refactor : 重构网络下载模块

新增通用下载接口，扩展了默认的Unity引擎下载器

Assets/YooAsset/Runtime/DiagnosticSystem/README.md

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+# DiagnosticSystem 诊断系统
+
+## 模块概述
+
+DiagnosticSystem 是 YooAsset 的**远程调试诊断系统**，提供运行时资源管理状态的实时可视化和性能分析能力。该系统通过编辑器窗口与运行时游戏进行双向通信，实时采集和展示资源加载、Bundle 管理、异步操作等调试信息。
+
+### 核心特性
+
+- **实时远程调试**：在 Unity 编辑器中查看游戏运行时的资源管理状态
+- **完整状态快照**：采集所有资源、Bundle、异步操作的实时信息
+- **历史数据回溯**：缓存最近 500 帧数据，支持时间回溯分析
+- **双模式采样**：支持单次采样和自动连续采样
+- **低性能开销**：按需采样，无需连续监控
+
+### 模块统计
+
+| 组件 | 职责 |
+|------|------|
+| 核心通信 | RemoteDebuggerInRuntime + 双连接层 |
+| 数据结构 | 5 个调试信息结构体 |
+| 命令系统 | RemoteCommand 命令定义 |
+| **总计** | 10 个核心文件，完整的远程诊断框架 |
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **实时可视化** | 在编辑器中实时查看运行时资源状态 |
+| **性能监控** | 收集加载耗时、引用计数、下载进度等性能指标 |
+| **内存诊断** | 追踪资源出生场景、引用计数，识别潜在内存泄漏 |
+| **操作追踪** | 显示异步操作树，包括嵌套和依赖关系 |
+| **低开销设计** | 按需采样而非连续监控，DEBUG 模式自动启用 |
+
+---
+
+## 文件结构
+
+```
+DiagnosticSystem/
+├── RemoteDebuggerDefine.cs        # 全局定义和常量
+├── RemoteCommand.cs                # 命令定义和序列化
+├── DebugReport.cs                  # 调试报告（顶层容器）
+├── DebugPackageData.cs             # 包级调试数据
+├── DebugProviderInfo.cs            # 资源加载器调试信息
+├── DebugBundleInfo.cs              # 资源包调试信息
+├── DebugOperationInfo.cs           # 异步操作调试信息
+├── RemoteDebuggerInRuntime.cs      # 运行时调试器主类
+├── RemotePlayerConnection.cs       # 编辑器模拟连接层
+└── RemoteEditorConnection.cs       # 运行时模拟连接层
+```
+
+---
+
+## 核心类说明
+
+### RemoteDebuggerDefine
+
+全局定义类，包含调试器版本和通信协议的 GUID 标识符。
+
+```csharp
+internal class RemoteDebuggerDefine
+{
+    // 调试器版本（用于版本校验）
+    public const string DebuggerVersion = "2.3.3";
+
+    // 消息标识符（GUID）
+    public static readonly Guid kMsgPlayerSendToEditor =
+        new Guid("e34a5702dd353724aa315fb8011f08c3");  // 运行时→编辑器
+
+    public static readonly Guid kMsgEditorSendToPlayer =
+        new Guid("4d1926c9df5b052469a1c63448b7609a");  // 编辑器→运行时
+}
+```
+
+### RemoteCommand
+
+命令定义类，用于编辑器向运行时发送采样指令。
+
+```csharp
+internal enum ERemoteCommand
+{
+    SampleOnce = 0,  // 单次采样
+    SampleAuto = 1,  // 自动采样（连续）
+}
+
+[Serializable]
+internal class RemoteCommand
+{
+    public int CommandType;      // ERemoteCommand 枚举值
+    public string CommandParam;  // 命令参数
+
+    // 序列化/反序列化（JSON 格式）
+    public static byte[] Serialize(RemoteCommand command)
+    {
+        return Encoding.UTF8.GetBytes(JsonUtility.ToJson(command));
+    }
+
+    public static RemoteCommand Deserialize(byte[] data)
+    {
+        return JsonUtility.FromJson<RemoteCommand>(Encoding.UTF8.GetString(data));
+    }
+}
+```
+
+**命令示例：**
+
+```json
+// 单次采样
+{
+  "CommandType": 0,
+  "CommandParam": ""
+}
+
+// 开启自动采样
+{
+  "CommandType": 1,
+  "CommandParam": "open"
+}
+
+// 关闭自动采样
+{
+  "CommandType": 1,
+  "CommandParam": "close"
+}
+```
+
+### DebugReport
+
+调试报告容器，包含完整的系统状态快照。
+
+```csharp
+[Serializable]
+internal class DebugReport
+{
+    // 调试器版本（用于版本校验）
+    public string DebuggerVersion = RemoteDebuggerDefine.DebuggerVersion;
+
+    // 游戏帧数
+    public int FrameCount;
+
+    // 包级调试数据列表（一个游戏可能有多个资源包）
+    public List<DebugPackageData> PackageDatas = new List<DebugPackageData>(10);
+
+    // 序列化/反序列化
+    public static byte[] Serialize(DebugReport debugReport);
+    public static DebugReport Deserialize(byte[] data);
+}
+```
+
+### DebugPackageData
+
+包级调试数据，包含单个资源包的所有诊断信息。
+
+```csharp
+[Serializable]
+internal class DebugPackageData
+{
+    // 资源包名称
+    public string PackageName;
+
+    // 资源加载器列表
+    public List<DebugProviderInfo> ProviderInfos = new List<DebugProviderInfo>(1000);
+
+    // 资源包列表
+    public List<DebugBundleInfo> BundleInfos = new List<DebugBundleInfo>(1000);
+
+    // 异步操作列表
+    public List<DebugOperationInfo> OperationInfos = new List<DebugOperationInfo>(1000);
+
+    // 运行时查询字典（非序列化，按需构建）
+    [NonSerialized]
+    public Dictionary<string, DebugBundleInfo> BundleInfoDic;
+
+    // 延迟解析字典
+    public DebugBundleInfo GetBundleInfo(string bundleName);
+}
+```
+
+### DebugProviderInfo
+
+资源加载器（Provider）的调试信息。
+
+```csharp
+[Serializable]
+internal struct DebugProviderInfo : IComparer<DebugProviderInfo>, IComparable<DebugProviderInfo>
+{
+    public string PackageName;           // 所属包名
+    public string AssetPath;             // 资源路径（如 "Assets/Prefabs/Player.prefab"）
+    public string SpawnScene;            // 资源加载时的活跃场景名
+    public string BeginTime;             // 加载开始时间（格式：HH:mm:ss.fff）
+    public long LoadingTime;             // 加载耗时（单位：毫秒）
+    public int RefCount;                 // 引用计数
+    public string Status;                // 加载状态（None/Processing/Succeed/Failed）
+    public List<string> DependBundles;   // 依赖的资源包名列表
+
+    // 按 AssetPath 字母排序
+    public int CompareTo(DebugProviderInfo other);
+}
+```
+
+**关键诊断价值：**
+- `SpawnScene`：追踪资源在哪个场景被加载，帮助识别资源泄漏
+- `LoadingTime`：性能分析，识别加载慢的资源
+- `RefCount`：引用计数监控，RefCount > 0 表示资源仍在使用
+- `DependBundles`：依赖分析，理解资源加载的完整依赖链
+
+### DebugBundleInfo
+
+资源包（Bundle）的调试信息。
+
+```csharp
+[Serializable]
+internal struct DebugBundleInfo : IComparer<DebugBundleInfo>, IComparable<DebugBundleInfo>
+{
+    public string BundleName;              // 资源包名称
+    public int RefCount;                   // 引用计数（当前有多少个 Provider 在使用）
+    public string Status;                  // 加载状态
+    public List<string> ReferenceBundles;  // 反向依赖（谁引用了我）
+
+    // 按 BundleName 字母排序
+    public int CompareTo(DebugBundleInfo other);
+}
+```
+
+**关键诊断价值：**
+- `RefCount`：Bundle 引用计数，为 0 时可以被卸载
+- `ReferenceBundles`：反向依赖分析，了解 Bundle 被哪些其他 Bundle 依赖
+
+### DebugOperationInfo
+
+异步操作的调试信息，支持递归树结构。
+
+```csharp
+[Serializable]
+internal struct DebugOperationInfo : IComparer<DebugOperationInfo>, IComparable<DebugOperationInfo>
+{
+    public string OperationName;   // 操作类名（如 "LoadAssetOperation"）
+    public string OperationDesc;   // 操作说明（自定义描述）
+    public uint Priority;          // 优先级（用于操作排序）
+    public float Progress;         // 进度（0.0 - 1.0）
+    public string BeginTime;       // 操作开始时间
+    public long ProcessTime;       // 处理耗时（单位：毫秒）
+    public string Status;          // 操作状态（None/Processing/Succeed/Failed）
+    public List<DebugOperationInfo> Childs;  // 子操作列表（支持嵌套树结构）
+
+    public int CompareTo(DebugOperationInfo other);
+}
+```
+
+**递归树结构示例：**
+```
+InitializationOperation
+├─ LoadManifestOperation
+│  ├─ LoadBundleFileOperation (manifest.bundle)
+│  └─ DeserializeManifestOperation
+└─ InitFileSystemOperation
+```
+
+**关键诊断价值：**
+- `OperationName`：操作类型识别
+- `ProcessTime`：性能瓶颈分析
+- `Childs`：操作依赖关系可视化
+
+---
+
+## 通信系统
+
+### RemoteDebuggerInRuntime
+
+运行时调试器主类，负责接收命令、采样数据、发送报告。
+
+```csharp
+internal class RemoteDebuggerInRuntime : MonoBehaviour
+{
+    // 采样控制标志
+    private static bool _sampleOnce = false;      // 单次采样
+    private static bool _autoSample = false;      // 连续采样
+
+    // 运行时初始化
+    [RuntimeInitializeOnLoadMethod]
+    private static void RuntimeInitializeOnLoad()
+    {
+        _sampleOnce = false;
+        _autoSample = false;
+    }
+
+    private void Awake()
+    {
+        RemotePlayerConnection.Instance.Initialize();
+    }
+
+    private void OnEnable()
+    {
+        // 注册命令接收回调
+        RemotePlayerConnection.Instance.Register(
+            RemoteDebuggerDefine.kMsgEditorSendToPlayer,
+            OnHandleEditorMessage);
+    }
+
+    private void LateUpdate()
+    {
+        // 采样逻辑（在一帧的最后执行）
+        if (_autoSample || _sampleOnce)
+        {
+            _sampleOnce = false;
+            var debugReport = YooAssets.GetDebugReport();
+            var data = DebugReport.Serialize(debugReport);
+
+            RemotePlayerConnection.Instance.Send(
+                RemoteDebuggerDefine.kMsgPlayerSendToEditor,
+                data);
+        }
+    }
+
+    private static void OnHandleEditorMessage(MessageEventArgs args)
+    {
+        var command = RemoteCommand.Deserialize(args.data);
+
+        if (command.CommandType == (int)ERemoteCommand.SampleOnce)
+        {
+            _sampleOnce = true;
+        }
+        else if (command.CommandType == (int)ERemoteCommand.SampleAuto)
+        {
+            _autoSample = (command.CommandParam == "open");
+        }
+    }
+}
+```
+
+**关键设计点：**
+1. **LateUpdate 时机**：确保该帧所有资源加载完成后再采样
+2. **状态重置**：`[RuntimeInitializeOnLoadMethod]` 确保编辑器重新编译时重置状态
+3. **DEBUG 模式自动启用**：通过 `#if DEBUG` 条件编译自动添加组件
+
+### 双连接层架构
+
+YooAsset 支持两种通信模式：
+
+| 模式 | 使用场景 | 实现方式 |
+|------|----------|----------|
+| **编辑器模拟模式** | 开发调试 | `RemotePlayerConnection` + `RemoteEditorConnection`（虚拟连接） |
+| **发布版本** | 运营期监控 | Unity 的 `PlayerConnection` API（真实网络） |
+
+#### RemotePlayerConnection（编辑器模拟模式）
+
+```csharp
+internal class RemotePlayerConnection
+{
+    private static RemotePlayerConnection _instance;
+    private readonly Dictionary<Guid, UnityAction<MessageEventArgs>> _messageCallbacks;
+
+    public static RemotePlayerConnection Instance
+    {
+        get
+        {
+            if (_instance == null)
+                _instance = new RemotePlayerConnection();
+            return _instance;
+        }
+    }
+
+    public void Register(Guid messageID, UnityAction<MessageEventArgs> callback)
+    {
+        _messageCallbacks.Add(messageID, callback);
+    }
+
+    public void Send(Guid messageID, byte[] data)
+    {
+        // 在编辑器模拟模式下，发送给虚拟编辑器连接
+        RemoteEditorConnection.Instance.HandlePlayerMessage(messageID, data);
+    }
+
+    internal void HandleEditorMessage(Guid messageID, byte[] data)
+    {
+        if (_messageCallbacks.TryGetValue(messageID, out var callback))
+        {
+            callback.Invoke(new MessageEventArgs { playerId = 0, data = data });
+        }
+    }
+}
+```
+
+#### RemoteEditorConnection（运行时模拟模式）
+
+```csharp
+internal class RemoteEditorConnection
+{
+    private static RemoteEditorConnection _instance;
+    private readonly Dictionary<Guid, UnityAction<MessageEventArgs>> _messageCallbacks;
+
+    public static RemoteEditorConnection Instance
+    {
+        get
+        {
+            if (_instance == null)
+                _instance = new RemoteEditorConnection();
+            return _instance;
+        }
+    }
+
+    public void Register(Guid messageID, UnityAction<MessageEventArgs> callback)
+    {
+        _messageCallbacks.Add(messageID, callback);
+    }
+
+    public void Send(Guid messageID, byte[] data)
+    {
+        // 发送给虚拟运行时连接
+        RemotePlayerConnection.Instance.HandleEditorMessage(messageID, data);
+    }
+
+    internal void HandlePlayerMessage(Guid messageID, byte[] data)
+    {
+        if (_messageCallbacks.TryGetValue(messageID, out var callback))
+        {
+            callback.Invoke(new MessageEventArgs { playerId = 0, data = data });
+        }
+    }
+}
+```
+
+---
+
+## 通信协议
+
+### 协议规范
+
+**协议版本：** 2.3.3
+
+**编码格式：**
+```
+C# 对象 → JsonUtility.ToJson() → JSON 字符串 → Encoding.UTF8.GetBytes() → byte[]
+```
+
+**消息类型：**
+
+| 方向 | GUID | 数据类型 | 说明 |
+|------|------|----------|------|
+| 编辑器→运行时 | `4d1926c9df5b052469a1c63448b7609a` | `RemoteCommand` | 采样命令 |
+| 运行时→编辑器 | `e34a5702dd353724aa315fb8011f08c3` | `DebugReport` | 调试报告 |
+
+### 双向通信流程
+
+```
+[编辑器 UI]
+  │
+  ├─ 用户点击 "Sample" 按钮
+  │   └─ 发送 RemoteCommand (SampleOnce)
+  │
+  └─ 用户开启 "Record" 开关
+      └─ 发送 RemoteCommand (SampleAuto, "open")
+
+      ↓ RemoteEditorConnection.Send()
+      ↓
+      RemotePlayerConnection.HandleEditorMessage()
+      ↓ 触发回调
+
+[运行时]
+  RemoteDebuggerInRuntime.OnHandleEditorMessage()
+  ↓
+  设置采样标志 (_sampleOnce 或 _autoSample)
+  ↓
+  LateUpdate 中采样
+  ↓
+  YooAssets.GetDebugReport()
+    ├─ 收集所有 ResourcePackage 数据
+    ├─ DebugProviderInfo[] (从 ProviderDic)
+    ├─ DebugBundleInfo[] (从 LoaderDic)
+    └─ DebugOperationInfo[] (从 _operations)
+  ↓
+  DebugReport.Serialize()
+  ↓
+  RemotePlayerConnection.Send()
+  ↓
+  RemoteEditorConnection.HandlePlayerMessage()
+  ↓
+
+[编辑器]
+  AssetBundleDebuggerWindow.OnHandlePlayerMessage()
+  ↓
+  版本校验 (DebuggerVersion)
+  ↓
+  RemotePlayerSession.AddDebugReport()
+  ↓
+  缓存到历史记录 (最多 500 帧)
+  ↓
+  UI 刷新显示
+```
+
+### 版本校验机制
+
+```csharp
+// 编辑器端版本校验
+private void OnHandlePlayerMessage(MessageEventArgs args)
+{
+    var debugReport = DebugReport.Deserialize(args.data);
+
+    // 版本校验
+    if (debugReport.DebuggerVersion != RemoteDebuggerDefine.DebuggerVersion)
+    {
+        Debug.LogWarning(
+            $"Debugger versions are inconsistent : " +
+            $"{debugReport.DebuggerVersion} != {RemoteDebuggerDefine.DebuggerVersion}");
+        return;  // 丢弃不兼容的数据
+    }
+
+    // 处理数据...
+}
+```
+
+**设计意图：** 防止编辑器和运行时的调试器版本不一致导致的数据格式错误。
+
+---
+
+## 数据收集流程
+
+### 完整采样流程
+
+```
+RemoteDebuggerInRuntime.LateUpdate()
+  ↓
+检查 _sampleOnce 或 _autoSample 标志
+  ↓ YES
+调用 YooAssets.GetDebugReport()
+  │
+  ├─ 初始化 DebugReport
+  ├─ 设置 FrameCount = Time.frameCount
+  ├─ 遍历每个 ResourcePackage：
+  │   │
+  │   └─ package.GetDebugPackageData()
+  │       │
+  │       ├─ 创建 DebugPackageData
+  │       ├─ 设置 PackageName
+  │       │
+  │       ├─ 收集 ProviderInfos：
+  │       │   ResourceManager.GetDebugProviderInfos()
+  │       │   遍历 ProviderDic：
+  │       │     └─ 每个 ProviderOperation 提供：
+  │       │         - MainAssetInfo.AssetPath
+  │       │         - SpawnScene（场景名）
+  │       │         - BeginTime（开始时间）
+  │       │         - ProcessTime（耗时）
+  │       │         - RefCount（引用计数）
+  │       │         - Status（加载状态）
+  │       │         - GetDebugDependBundles()（依赖列表）
+  │       │
+  │       ├─ 收集 BundleInfos：
+  │       │   ResourceManager.GetDebugBundleInfos()
+  │       │   遍历 LoaderDic：
+  │       │     └─ 每个 LoadBundleFileOperation 提供：
+  │       │         - BundleName
+  │       │         - RefCount
+  │       │         - Status
+  │       │         - FilterReferenceBundles()（反向依赖）
+  │       │
+  │       └─ 收集 OperationInfos：
+  │           OperationSystem.GetDebugOperationInfos(PackageName)
+  │           遍历 _operations（按 PackageName 过滤）：
+  │             └─ 递归构建操作树：
+  │                 - GetType().Name（操作类名）
+  │                 - GetOperationDesc()（自定义描述）
+  │                 - Priority（优先级）
+  │                 - Progress（进度）
+  │                 - BeginTime（开始时间）
+  │                 - ProcessTime（耗时）
+  │                 - Status（状态）
+  │                 - Childs（子操作列表）
+  │
+  └─ 返回 DebugReport
+```
+
+### 性能指标收集
+
+#### 资源加载耗时
+
+```csharp
+// AsyncOperationBase 中的自动计时
+private Stopwatch _watch = null;
+
+internal void InternalStart()
+{
+    if (_watch == null)
+    {
+        BeginTime = SpawnTimeToString(UnityEngine.Time.realtimeSinceStartup);
+        _watch = Stopwatch.StartNew();
+    }
+}
+
+internal void InternalUpdate()
+{
+    ProcessTime = _watch.ElapsedMilliseconds;
+    // ... 持续计时
+}
+```
+
+#### 场景信息追踪
+
+```csharp
+// ProviderOperation.cs
+[Conditional("DEBUG")]  // 仅在 DEBUG 模式下启用
+public void InitProviderDebugInfo()
+{
+    SpawnScene = UnityEngine.SceneManagement.SceneManager.GetActiveScene().name;
+}
+```
+
+#### 引用计数监控
+
+```csharp
+// ProviderOperation 和 LoadBundleFileOperation 都维护 RefCount
+public int RefCount { get; }  // 当前被引用的次数
+```
+
+---
+
+## 与其他模块的交互
+
+```
+YooAssets (全局入口)
+    │
+    ├─ 初始化阶段：
+    │   #if DEBUG
+    │   _driver.AddComponent<RemoteDebuggerInRuntime>();
+    │   #endif
+    │
+    └─ 数据收集入口：
+        GetDebugReport()
+            ├─ 遍历所有 ResourcePackage
+            └─ 构建 DebugReport
+
+ResourcePackage (资源包)
+    │
+    └─ GetDebugPackageData()
+        ├─ 调用 ResourceManager.GetDebugProviderInfos()
+        ├─ 调用 ResourceManager.GetDebugBundleInfos()
+        └─ 调用 OperationSystem.GetDebugOperationInfos()
+
+ResourceManager (资源管理器)
+    │
+    ├─ GetDebugProviderInfos()
+    │   └─ 遍历 ProviderDic (Dictionary<string, ProviderOperation>)
+    │
+    └─ GetDebugBundleInfos()
+        └─ 遍历 LoaderDic (Dictionary<string, LoadBundleFileOperation>)
+
+OperationSystem (操作系统)
+    │
+    └─ GetDebugOperationInfos(packageName)
+        └─ 遍历 _operations (List<AsyncOperationBase>)
+            └─ 递归收集子操作 (Childs)
+
+AsyncOperationBase (异步操作基类)
+    │
+    ├─ BeginTime：操作开始时间
+    ├─ ProcessTime：累计处理耗时
+    ├─ Status：操作状态
+    ├─ Progress：进度
+    └─ GetOperationDesc()：自定义描述
+
+ProviderOperation (资源提供者)
+    │
+    ├─ SpawnScene：加载时的活跃场景
+    └─ GetDebugDependBundles()：依赖包列表
+
+LoadBundleFileOperation (Bundle 加载器)
+    │
+    ├─ RefCount：引用计数
+    └─ LoadBundleInfo：Bundle 信息
+```
+
+---
+
+## 使用场景
+
+### 场景 1：运行时资源泄漏诊断
+
+**问题：** 游戏切换场景后内存持续增长，怀疑有资源未释放。
+
+**诊断步骤：**
+1. 打开 AssetBundle Debugger 窗口
+2. 开启 Record 模式（自动采样）
+3. 切换场景前后观察 ProviderInfos 列表
+4. 检查 `RefCount > 0` 且 `SpawnScene` 为旧场景的资源
+5. 定位未释放的资源和对应的代码位置
+
+**关键字段：**
+- `SpawnScene`：资源在哪个场景被加载
+- `RefCount`：引用计数，应该为 0
+- `AssetPath`：资源路径，定位具体资源
+
+### 场景 2：资源加载性能分析
+
+**问题：** 首次加载场景卡顿严重。
+
+**诊断步骤：**
+1. 单次采样（Sample Once）
+2. 切换到 Asset View
+3. 按 `LoadingTime` 降序排序
+4. 识别加载耗时最长的资源
+5. 分析 `DependBundles` 了解依赖链
+
+**关键字段：**
+- `LoadingTime`：加载耗时（毫秒）
+- `DependBundles`：依赖的 Bundle 列表
+- `Status`：加载状态
+
+### 场景 3：Bundle 引用分析
+
+**问题：** 某个 Bundle 无法被卸载。
+
+**诊断步骤：**
+1. 切换到 Bundle View
+2. 搜索目标 Bundle
+3. 检查 `RefCount` 和 `ReferenceBundles`
+4. 追踪哪些资源正在使用该 Bundle
+5. 定位未释放的资源引用
+
+**关键字段：**
+- `RefCount`：Bundle 引用计数
+- `ReferenceBundles`：反向依赖列表
+- `Status`：Bundle 加载状态
+
+### 场景 4：异步操作监控
+
+**问题：** 复杂的初始化流程卡住，不知道在哪个步骤。
+
+**诊断步骤：**
+1. 切换到 Operation View
+2. 查看操作树结构
+3. 检查 `Status` 为 `Processing` 的操作
+4. 分析 `Progress` 了解进度
+5. 通过 `Childs` 了解操作依赖关系
+
+**关键字段：**
+- `OperationName`：操作类型
+- `OperationDesc`：操作描述
+- `Progress`：进度（0.0 - 1.0）
+- `Childs`：子操作列表
+
+---
+
+## 数据导出
+
+### JSON 导出功能
+
+编辑器窗口支持导出当前帧的完整调试数据为 JSON 文件。
+
+**导出示例：**
+
+```json
+{
+  "DebuggerVersion": "2.3.3",
+  "FrameCount": 1234,
+  "PackageDatas": [
+    {
+      "PackageName": "DefaultPackage",
+      "ProviderInfos": [
+        {
+          "PackageName": "DefaultPackage",
+          "AssetPath": "Assets/Prefabs/Player.prefab",
+          "SpawnScene": "GameScene",
+          "BeginTime": "12:34:56.789",
+          "LoadingTime": 45,
+          "RefCount": 1,
+          "Status": "Succeed",
+          "DependBundles": [
+            "assets_prefabs.bundle"
+          ]
+        }
+      ],
+      "BundleInfos": [
+        {
+          "BundleName": "assets_prefabs.bundle",
+          "RefCount": 1,
+          "Status": "Succeed",
+          "ReferenceBundles": []
+        }
+      ],
+      "OperationInfos": [
+        {
+          "OperationName": "LoadAssetOperation",
+          "OperationDesc": "Load assets_prefabs.bundle",
+          "Priority": 0,
+          "Progress": 1.0,
+          "BeginTime": "12:34:56.745",
+          "ProcessTime": 44,
+          "Status": "Succeed",
+          "Childs": []
+        }
+      ]
+    }
+  ]
+}
+```
+
+**用途：**
+- 离线分析和归档
+- 性能数据对比
+- 问题复现和追踪
+
+---
+
+## 系统架构图
+
+```
+┌─────────────────────────────────────────────────────────────────────┐
+│                        Unity Editor Window                           │
+│                   AssetBundleDebuggerWindow                          │
+│  ┌──────────────────────────────────────────────────────────────┐   │
+│  │ UI Controls:                                                  │   │
+│  │  - Sample Button (SampleOnce)                               │   │
+│  │  - Record Toggle (SampleAuto)                               │   │
+│  │  - View Mode Menu (Asset/Bundle/Operation View)            │   │
+│  │  - Frame Slider (历史帧导航)                                │   │
+│  │  - Search Field (关键词搜索)                                │   │
+│  │  - Export Button (JSON 导出)                                │   │
+│  └──────────────────────────────────────────────────────────────┘   │
+└────────────┬──────────────────────────────────────────────────────────┘
+             │
+       ┌─────▼───────────────────────────────────┐
+       │  RemoteEditorConnection (虚拟连接)       │
+       │  - Register callbacks                   │
+       │  - Send/Receive commands & reports      │
+       └─────┬──────────────────────────────┬────┘
+             │                              │
+    ┌────────▼─────────────┐    ┌──────────▼───────────────┐
+    │  RemoteCommand       │    │  DebugReport             │
+    │  (Serialize)         │    │  (Deserialize)           │
+    │  ↓ JSON              │    │  ← JSON                  │
+    │  ↓ UTF-8 bytes       │    │  ← UTF-8 bytes           │
+    └────────┬─────────────┘    └──────────┬───────────────┘
+             │                              │
+             │    ═══════════════════════   │
+             │    Internet / Emulation      │
+             │    ═══════════════════════   │
+             │                              │
+    ┌────────▼─────────────┐    ┌──────────▼───────────────┐
+    │  PlayerConnection    │    │  RemotePlayerConnection  │
+    │  (真实连接)          │    │  (虚拟连接)              │
+    │  或模拟连接          │    │                          │
+    └────────┬─────────────┘    └──────────┬───────────────┘
+             │                              │
+             └──────────────┬───────────────┘
+                            │
+                     ┌──────▼──────────────────────────────┐
+                     │  RemoteDebuggerInRuntime             │
+                     │  (MonoBehaviour)                     │
+                     │  ┌──────────────────────────────┐   │
+                     │  │ _sampleOnce (bool)           │   │
+                     │  │ _autoSample (bool)           │   │
+                     │  └──────────────────────────────┘   │
+                     │  ┌──────────────────────────────┐   │
+                     │  │ Awake() - 初始化连接         │   │
+                     │  │ OnEnable() - 注册回调        │   │
+                     │  │ LateUpdate() - 采样触发      │   │
+                     │  │ OnHandleEditorMessage() - 收命令│  │
+                     │  └──────────────────────────────┘   │
+                     └──────────┬──────────────────────────┘
+                                │
+                         ┌──────▼────────────────────┐
+                         │  YooAssets.GetDebugReport() │
+                         │  (全系统数据收集入口)      │
+                         └──────┬────────────────────┘
+                                │
+                    ┌───────────┼───────────┐
+                    │           │           │
+         ┌──────────▼──┐  ┌─────▼────┐  ┌──▼─────────────┐
+         │ResourcePkg 1│  │ResourcePkg2  │ResourcePackageN│
+         └──────┬──────┘  └────┬─────┘  └──┬──────────┘
+                │               │          │
+                └───────────────┼──────────┘
+                                │
+                    ┌───────────▼──────────┐
+                    │ DebugPackageData     │
+                    │ ┌─────────────────┐  │
+                    │ │ PackageName     │  │
+                    │ │ ProviderInfos[] │  │
+                    │ │ BundleInfos[]   │  │
+                    │ │ OperationInfos[]│  │
+                    │ └─────────────────┘  │
+                    └─────────────────────┘
+```
+
+---
+
+## 注意事项
+
+1. **DEBUG 模式自动启用**
+   - 诊断系统仅在 `DEBUG` 模式下启用（通过 `#if DEBUG` 条件编译）
+   - Release 构建中不会包含诊断代码，无性能开销
+
+2. **版本兼容性**
+   - 编辑器和运行时的调试器版本必须一致
+   - 版本不一致的数据会被自动丢弃
+
+3. **历史数据限制**
+   - 最多缓存 500 帧历史数据（可配置）
+   - 超过限制后，最早的数据会被移除
+
+4. **JSON 序列化深度限制**
+   - Unity JsonUtility 序列化深度限制为 10 层
+   - 操作树（Childs）嵌套过深可能导致序列化失败
+
+5. **性能开销**
+   - 单次采样：低开销，仅在需要时采集
+   - 自动采样：每帧采集，有一定性能开销，建议仅在需要时开启
+
+6. **LateUpdate 时机**
+   - 采样在 LateUpdate 中执行，确保该帧所有操作已更新
+   - 避免在采样过程中资源状态发生变化
+
+7. **非序列化字典**
+   - `DebugPackageData.BundleInfoDic` 使用 `[NonSerialized]` 标记
+   - 字典在首次查询时才构建，减少序列化开销
+
+8. **场景追踪条件编译**
+   - `SpawnScene` 字段仅在 DEBUG 模式下赋值（`[Conditional("DEBUG")]`）
+   - Release 构建中该字段为空字符串
+
+---
+
+## 性能优化建议
+
+1. **按需采样**
+   - 优先使用单次采样（Sample Once）
+   - 仅在需要连续监控时开启自动采样（Record）
+
+2. **及时关闭 Record**
+   - 分析完成后及时关闭自动采样
+   - 避免不必要的性能开销
+
+3. **合理设置历史缓存**
+   - 根据内存情况调整 `MaxReportCount`
+   - 默认 500 帧已足够大多数分析场景
+
+4. **导出数据离线分析**
+   - 对于复杂的性能问题，导出 JSON 数据
+   - 在编辑器外使用专业工具进行分析
+
+5. **Release 构建移除诊断代码**
+   - 确保 Release 构建使用 Release 配置
+   - 诊断代码通过 `#if DEBUG` 自动移除

Assets/YooAsset/Runtime/DiagnosticSystem/README.md.meta

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Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadBackend.meta

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   externalObjects: {}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadBackend/UnityWebRequestBackend.cs

@@ -0,0 +1,110 @@
+using System;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest 下载后台
+    /// </summary>
+    /// <remarks>
+    /// 基于 Unity 内置 UnityWebRequest 实现的下载后台。
+    /// 支持自定义 UnityWebRequest 创建方式，例如添加证书验证、代理设置等。
+    /// </remarks>
+    internal sealed class UnityWebRequestBackend : IDownloadBackend
+    {
+        private readonly UnityWebRequestCreator _webRequestCreator;
+
+        /// <summary>
+        /// 后端名称
+        /// </summary>
+        public string Name
+        {
+            get { return nameof(UnityWebRequestBackend); }
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest 下载后端（使用默认创建方式）
+        /// </summary>
+        public UnityWebRequestBackend() : this(null)
+        {
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest 下载后端
+        /// </summary>
+        /// <param name="webRequestCreator">
+        /// 自定义 UnityWebRequest 创建委托（可选）。
+        /// 如果为 null，则使用默认的 UnityWebRequest 构造方式。
+        /// </param>
+        public UnityWebRequestBackend(UnityWebRequestCreator webRequestCreator)
+        {
+            _webRequestCreator = webRequestCreator;
+        }
+
+        /// <summary>
+        /// 驱动更新
+        /// </summary>
+        /// <remarks>
+        /// UnityWebRequest 由 Unity 引擎自动驱动，无需额外更新。
+        /// </remarks>
+        public void Update()
+        {
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        public void Dispose()
+        {
+            // 无需释放资源
+        }
+
+        /// <summary>
+        /// 创建 HEAD 请求
+        /// </summary>
+        public IDownloadHeadRequest CreateHeadRequest(DownloadDataRequestArgs args)
+        {
+            return new UnityWebRequestHeadDownloader(args, _webRequestCreator);
+        }
+
+        /// <summary>
+        /// 创建文件下载请求
+        /// </summary>
+        public IDownloadFileRequest CreateFileRequest(DownloadFileRequestArgs args)
+        {
+            return new UnityWebRequestFileDownloader(args, _webRequestCreator);
+        }
+
+        /// <summary>
+        /// 创建字节下载请求
+        /// </summary>
+        public IDownloadBytesRequest CreateBytesRequest(DownloadDataRequestArgs args)
+        {
+            return new UnityWebRequestBytesDownloader(args, _webRequestCreator);
+        }
+
+        /// <summary>
+        /// 创建文本下载请求
+        /// </summary>
+        public IDownloadTextRequest CreateTextRequest(DownloadDataRequestArgs args)
+        {
+            return new UnityWebRequestTextDownloader(args, _webRequestCreator);
+        }
+
+        /// <summary>
+        /// 创建 AssetBundle 下载请求
+        /// </summary>
+        public IDownloadAssetBundleRequest CreateAssetBundleRequest(DownloadAssetBundleRequestArgs args)
+        {
+            return new UnityWebRequestAssetBundleDownloader(args, _webRequestCreator);
+        }
+
+        /// <summary>
+        /// 创建模拟下载请求
+        /// </summary>
+        public IDownloadFileRequest CreateSimulateRequest(DownloadSimulateRequestArgs args)
+        {
+            return new VirtualFileDownloader(args);
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadBackend/UnityWebRequestBackend.cs.meta

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+  userData: 
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+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadBackend/UnityWebRequestCreator.cs

@@ -0,0 +1,10 @@
+using UnityEngine.Networking;
+using UnityEngine;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 自定义下载器的请求委托
+    /// </summary>
+    public delegate UnityWebRequest UnityWebRequestCreator(string url, string method);
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadBackend/UnityWebRequestCreator.cs.meta

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Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest.meta

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+guid: 1d30af9086de4fb282c2cdd3d26244c0
+folderAsset: yes
+DefaultImporter:
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestAssetBundleDownloader.cs

@@ -0,0 +1,90 @@
+using System;
+using UnityEngine;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest AssetBundle 下载器
+    /// </summary>
+    /// <remarks>
+    /// 下载并加载 Unity AssetBundle 资源包。
+    /// 支持 Unity 内置缓存机制和 CRC 校验。
+    /// </remarks>
+    internal sealed class UnityWebRequestAssetBundleDownloader : UnityWebRequestDownloaderBase, IDownloadAssetBundleRequest
+    {
+        private readonly DownloadAssetBundleRequestArgs _args;
+        private DownloadHandlerAssetBundle _downloadHandler;
+
+        /// <summary>
+        /// 下载结果（AssetBundle 对象）
+        /// </summary>
+        public AssetBundle Result { get; private set; }
+
+        /// <summary>
+        /// 构造 AssetBundle 下载器
+        /// </summary>
+        /// <param name="args">AssetBundle 下载参数</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        public UnityWebRequestAssetBundleDownloader(DownloadAssetBundleRequestArgs args, UnityWebRequestCreator webRequestCreator)
+            : base(args.URL, webRequestCreator)
+        {
+            _args = args;
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest
+        /// </summary>
+        protected override void CreateWebRequest()
+        {
+            _downloadHandler = CreateAssetBundleDownloadHandler();
+            _webRequest = CreateUnityWebRequestGet(URL);
+            _webRequest.downloadHandler = _downloadHandler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+            ApplyRequestOptions(_args.Timeout, _args.WatchdogTime, _args.Headers);
+        }
+
+        /// <summary>
+        /// 请求成功时的回调
+        /// </summary>
+        protected override void OnRequestSucceed()
+        {
+            AssetBundle assetBundle = _downloadHandler.assetBundle;
+            if (assetBundle == null)
+            {
+                Status = EDownloadRequestStatus.Failed;
+                Error = $"[{GetType().Name}] URL: {URL} - AssetBundle object is null";
+            }
+            else
+            {
+                Result = assetBundle;
+            }
+        }
+
+        /// <summary>
+        /// 创建 AssetBundle 下载处理器
+        /// </summary>
+        private DownloadHandlerAssetBundle CreateAssetBundleDownloadHandler()
+        {
+            DownloadHandlerAssetBundle handler;
+
+            if (_args.DisableUnityWebCache)
+            {
+                // 禁用 Unity 缓存
+                handler = new DownloadHandlerAssetBundle(URL, _args.UnityCRC);
+            }
+            else
+            {
+                if (string.IsNullOrEmpty(_args.FileHash))
+                    throw new YooInternalException("File hash is null or empty !");
+
+                // 使用 Unity 缓存
+                // 说明：The file hash defining the version of the asset bundle.
+                Hash128 fileHash = Hash128.Parse(_args.FileHash);
+                handler = new DownloadHandlerAssetBundle(URL, fileHash, _args.UnityCRC);
+            }
+
+            return handler;
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestAssetBundleDownloader.cs.meta

@@ -1,5 +1,5 @@
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   serializedVersion: 2

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestBytesDownloader.cs

@@ -0,0 +1,52 @@
+using System;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest 字节下载器
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容保存到内存中的字节数组。
+    /// </remarks>
+    internal sealed class UnityWebRequestBytesDownloader : UnityWebRequestDownloaderBase, IDownloadBytesRequest
+    {
+        private readonly DownloadDataRequestArgs _args;
+
+        /// <summary>
+        /// 下载结果（字节数组）
+        /// </summary>
+        public byte[] Result { get; private set; }
+
+        /// <summary>
+        /// 构造字节数组下载器
+        /// </summary>
+        /// <param name="args">数据下载参数</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        public UnityWebRequestBytesDownloader(DownloadDataRequestArgs args, UnityWebRequestCreator webRequestCreator)
+            : base(args.URL, webRequestCreator)
+        {
+            _args = args;
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest
+        /// </summary>
+        protected override void CreateWebRequest()
+        {
+            var handler = new DownloadHandlerBuffer();
+            _webRequest = CreateUnityWebRequestGet(URL);
+            _webRequest.downloadHandler = handler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+            ApplyRequestOptions(_args.Timeout, _args.WatchdogTime, _args.Headers);
+        }
+
+        /// <summary>
+        /// 请求成功时的回调
+        /// </summary>
+        protected override void OnRequestSucceed()
+        {
+            Result = _webRequest.downloadHandler.data;
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestBytesDownloader.cs.meta

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   serializedVersion: 2

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestDownloaderBase.cs

@@ -0,0 +1,293 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest 下载器基类
+    /// </summary>
+    /// <remarks>
+    /// 封装 UnityWebRequest 的通用下载逻辑，包括状态管理、进度追踪等。
+    /// 子类只需实现 CreateWebRequest 方法来创建特定类型的下载请求。
+    /// </remarks>
+    internal abstract class UnityWebRequestDownloaderBase : IDownloadRequest
+    {
+        private readonly UnityWebRequestCreator _webRequestCreator;
+        protected UnityWebRequest _webRequest;
+
+        // 看门狗相关
+        private int _watchdogTime = 0;
+        private bool _watchdogAborted = false;
+        private long _lastDownloadBytes = -1;
+        private double _lastGetDataTime;
+
+        #region 接口实现
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        public string URL { get; }
+
+        /// <summary>
+        /// 是否完成
+        /// </summary>
+        /// <remarks>
+        /// 每次调用都会主动轮询请求 PollingRequest
+        /// </remarks>
+        public bool IsDone
+        {
+            get
+            {
+                PollingRequest();
+                return Status == EDownloadRequestStatus.Succeed
+                    || Status == EDownloadRequestStatus.Failed
+                    || Status == EDownloadRequestStatus.Aborted;
+            }
+        }
+
+        /// <summary>
+        /// 请求状态
+        /// </summary>
+        public EDownloadRequestStatus Status { get; protected set; }
+
+        /// <summary>
+        /// 当前下载进度（0f - 1f）
+        /// </summary>
+        public float DownloadProgress { get; private set; }
+
+        /// <summary>
+        /// 当前请求已接收的字节数
+        /// </summary>
+        public long DownloadedBytes { get; private set; }
+
+        /// <summary>
+        /// HTTP 返回码
+        /// </summary>
+        public long HttpCode { get; private set; }
+
+        /// <summary>
+        /// 错误信息
+        /// </summary>
+        public string Error { get; protected set; }
+        #endregion
+
+        /// <summary>
+        /// 构造下载器基类
+        /// </summary>
+        /// <param name="url">请求地址</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        protected UnityWebRequestDownloaderBase(string url, UnityWebRequestCreator webRequestCreator)
+        {
+            URL = url;
+            _webRequestCreator = webRequestCreator;
+            Status = EDownloadRequestStatus.None;
+        }
+
+        /// <summary>
+        /// 发起请求
+        /// </summary>
+        public void SendRequest()
+        {
+            if (Status == EDownloadRequestStatus.None)
+            {
+                Status = EDownloadRequestStatus.Running;
+
+                try
+                {
+                    CreateWebRequest();
+
+                    if (_webRequest == null)
+                    {
+                        Status = EDownloadRequestStatus.Failed;
+                        Error = $"[{GetType().Name}] Created web request is null.";
+                    }
+                    else
+                    {
+                        _webRequest.SendWebRequest();
+                    }
+                }
+                catch (Exception ex)
+                {
+                    Status = EDownloadRequestStatus.Failed;
+                    Error = $"[{GetType().Name}] Failed to create web request : {ex.Message}";
+                }
+            }
+        }
+
+        /// <summary>
+        /// 轮询请求
+        /// </summary>
+        public void PollingRequest()
+        {
+            if (Status != EDownloadRequestStatus.Running)
+                return;
+
+            DownloadProgress = _webRequest.downloadProgress;
+            DownloadedBytes = (long)_webRequest.downloadedBytes;
+
+            CheckWatchdog();
+            if (_webRequest.isDone == false)
+                return;
+
+            HttpCode = _webRequest.responseCode;
+#if UNITY_2020_3_OR_NEWER
+            bool isSuccess = _webRequest.result == UnityWebRequest.Result.Success;
+#else
+            bool isSuccess = !_webRequest.isNetworkError && !_webRequest.isHttpError;
+#endif
+
+            if (isSuccess)
+            {
+                Status = EDownloadRequestStatus.Succeed;
+                OnRequestSucceed();
+            }
+            else
+            {
+                Status = EDownloadRequestStatus.Failed;
+                Error = $"[{GetType().Name}] URL: {URL} - 错误: {_webRequest.error}";
+                OnRequestFailed();
+            }
+
+            // 完成后释放
+            DisposeWebRequest();
+        }
+
+        /// <summary>
+        /// 中止请求
+        /// </summary>
+        public void AbortRequest()
+        {
+            if (Status == EDownloadRequestStatus.None || Status == EDownloadRequestStatus.Running)
+            {
+                Status = EDownloadRequestStatus.Aborted;
+                if (_webRequest != null)
+                    _webRequest.Abort();
+            }
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        public void Dispose()
+        {
+            DisposeWebRequest();
+        }
+
+
+        /// <summary>
+        /// 创建 UnityWebRequest（子类实现）
+        /// </summary>
+        protected abstract void CreateWebRequest();
+
+        /// <summary>
+        /// 请求成功时的回调（子类可重写）
+        /// </summary>
+        protected virtual void OnRequestSucceed()
+        {
+        }
+
+        /// <summary>
+        /// 请求失败时的回调（子类可重写）
+        /// </summary>
+        protected virtual void OnRequestFailed()
+        {
+        }
+
+
+        /// <summary>
+        /// 创建 UnityWebRequest GET 请求
+        /// </summary>
+        /// <param name="requestUrl">请求地址</param>
+        /// <returns>UnityWebRequest 实例</returns>
+        protected UnityWebRequest CreateUnityWebRequestGet(string requestUrl)
+        {
+            if (_webRequestCreator != null)
+                return _webRequestCreator.Invoke(requestUrl, UnityWebRequest.kHttpVerbGET);
+
+            return new UnityWebRequest(requestUrl, UnityWebRequest.kHttpVerbGET);
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest HEAD 请求
+        /// </summary>
+        /// <param name="requestUrl">请求地址</param>
+        /// <returns>UnityWebRequest 实例</returns>
+        protected UnityWebRequest CreateUnityWebRequestHead(string requestUrl)
+        {
+            if (_webRequestCreator != null)
+                return _webRequestCreator.Invoke(requestUrl, UnityWebRequest.kHttpVerbHEAD);
+
+            return new UnityWebRequest(requestUrl, UnityWebRequest.kHttpVerbHEAD);
+        }
+
+        /// <summary>
+        /// 应用通用请求参数
+        /// </summary>
+        protected void ApplyRequestOptions(int timeout, int watchdogTime, Dictionary<string, string> headers)
+        {
+            if (_webRequest == null)
+                throw new YooInternalException("Web request is null !");
+
+            // 设置看门狗超时时间
+            _watchdogTime = watchdogTime;
+
+            // 设置响应的超时时间
+            if (timeout > 0)
+                _webRequest.timeout = timeout;
+
+            // 设置响应头
+            if (headers != null)
+            {
+                foreach (var header in headers)
+                {
+                    _webRequest.SetRequestHeader(header.Key, header.Value);
+                }
+            }
+        }
+
+        /// <summary>
+        /// 检测看门狗
+        /// </summary>
+        private void CheckWatchdog()
+        {
+            if (_watchdogTime == 0)
+                return;
+            if (_watchdogAborted)
+                return;
+
+#if UNITY_2020_3_OR_NEWER
+            double realtimeSinceStartup = UnityEngine.Time.realtimeSinceStartupAsDouble;
+#else
+            double realtimeSinceStartup = UnityEngine.Time.realtimeSinceStartup;
+#endif
+
+            if (DownloadedBytes != _lastDownloadBytes)
+            {
+                _lastDownloadBytes = DownloadedBytes;
+                _lastGetDataTime = realtimeSinceStartup;
+            }
+            else
+            {
+                double deltaTime = realtimeSinceStartup - _lastGetDataTime;
+                if (deltaTime > _watchdogTime)
+                {
+                    _watchdogAborted = true;
+                    AbortRequest(); //看门狗终止网络请求
+                }
+            }
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        private void DisposeWebRequest()
+        {
+            if (_webRequest != null)
+            {
+                //注意：引擎底层会自动调用Abort方法
+                _webRequest.Dispose();
+                _webRequest = null;
+            }
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestDownloaderBase.cs.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 9e71e850eded0da43906cb4f7cb75629
+guid: 76b0712524ed69542914db8e44fa64fd
 MonoImporter:
   externalObjects: {}
   serializedVersion: 2

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestFileDownloader.cs

@@ -0,0 +1,56 @@
+using System;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest 文件下载器
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容保存到本地文件，支持断点续传和追加写入。
+    /// </remarks>
+    internal sealed class UnityWebRequestFileDownloader : UnityWebRequestDownloaderBase, IDownloadFileRequest
+    {
+        private readonly DownloadFileRequestArgs _args;
+
+        /// <summary>
+        /// 文件保存路径
+        /// </summary>
+        public string SavePath
+        {
+            get { return _args.SavePath; }
+        }
+
+        /// <summary>
+        /// 构造文件下载器
+        /// </summary>
+        /// <param name="args">文件下载参数</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        public UnityWebRequestFileDownloader(DownloadFileRequestArgs args, UnityWebRequestCreator webRequestCreator)
+            : base(args.URL, webRequestCreator)
+        {
+            _args = args;
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest
+        /// </summary>
+        protected override void CreateWebRequest()
+        {
+            var handler = new DownloadHandlerFile(_args.SavePath, _args.AppendToFile);
+            handler.removeFileOnAbort = _args.RemoveFileOnAbort;
+
+            _webRequest = CreateUnityWebRequestGet(URL);
+            _webRequest.downloadHandler = handler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+
+            // 断点续传：设置 Range 请求头
+            if (_args.ResumeFromBytes > 0)
+            {
+                _webRequest.SetRequestHeader("Range", $"bytes={_args.ResumeFromBytes}-");
+            }
+
+            ApplyRequestOptions(_args.Timeout, _args.WatchdogTime, _args.Headers);
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestFileDownloader.cs.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 375d88bcf5b9a6146adaf98ceb5369f8
+guid: 101a4be1bb0a85c4d84ecbf3e74f89e4
 MonoImporter:
   externalObjects: {}
   serializedVersion: 2

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestHeadDownloader.cs

@@ -0,0 +1,124 @@
+using System;
+using System.Collections.Generic;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest HEAD 请求下载器
+    /// </summary>
+    /// <remarks>
+    /// 仅获取响应头信息，不下载实际内容。
+    /// 用于检查资源是否存在、获取资源大小、检查缓存有效性等场景。
+    /// </remarks>
+    internal sealed class UnityWebRequestHeadDownloader : UnityWebRequestDownloaderBase, IDownloadHeadRequest
+    {
+        // 注意：缓存响应头（因为 WebRequest 释放后无法获取）
+        private Dictionary<string, string> _cachedResponseHeaders;
+        private readonly DownloadDataRequestArgs _args;
+
+        /// <summary>
+        /// 获取 ETag 响应头
+        /// </summary>
+        public string ETag
+        {
+            get { return GetResponseHeader("ETag"); }
+        }
+
+        /// <summary>
+        /// 获取 Last-Modified 响应头
+        /// </summary>
+        public string LastModified
+        {
+            get { return GetResponseHeader("Last-Modified"); }
+        }
+
+        /// <summary>
+        /// 获取 Content-Type 响应头
+        /// </summary>
+        public string ContentType
+        {
+            get { return GetResponseHeader("Content-Type"); }
+        }
+
+        /// <summary>
+        /// 获取 Content-Length 响应头
+        /// 预期下载的总字节数
+        /// </summary>
+        public long ContentLength
+        {
+            get
+            {
+                string contentLengthStr = GetResponseHeader("Content-Length");
+                if (string.IsNullOrEmpty(contentLengthStr))
+                    return -1;
+
+                if (long.TryParse(contentLengthStr, out long contentLength))
+                {
+                    return contentLength;
+                }
+                else
+                {
+                    return -1;
+                }
+            }
+        }
+
+        /// <summary>
+        /// 构造 HEAD 请求下载器
+        /// </summary>
+        /// <param name="args">数据下载参数</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        public UnityWebRequestHeadDownloader(DownloadDataRequestArgs args, UnityWebRequestCreator webRequestCreator)
+                            : base(args.URL, webRequestCreator)
+        {
+            _args = args;
+        }
+
+        /// <summary>
+        /// 获取响应头信息
+        /// </summary>
+        /// <param name="name">响应头名称（不区分大小写）</param>
+        /// <returns>响应头的值，如果不存在或请求未完成则返回 null</returns>
+        public string GetResponseHeader(string name)
+        {
+            if (_cachedResponseHeaders == null)
+                return null;
+
+            // 注意：UnityWebRequest 的响应头 key 是小写的
+            string lowerName = name.ToLowerInvariant();
+            if (_cachedResponseHeaders.TryGetValue(lowerName, out string value))
+                return value;
+
+            return null;
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest
+        /// </summary>
+        protected override void CreateWebRequest()
+        {
+            _webRequest = CreateUnityWebRequestHead(URL);
+            _webRequest.downloadHandler = null; // HEAD 请求不需要 DownloadHandler
+            ApplyRequestOptions(_args.Timeout, _args.WatchdogTime, _args.Headers);
+        }
+
+        /// <summary>
+        /// 请求成功时的回调
+        /// </summary>
+        protected override void OnRequestSucceed()
+        {
+            var headers = _webRequest.GetResponseHeaders();
+            if (headers != null)
+            {
+                _cachedResponseHeaders = new Dictionary<string, string>(headers.Count, StringComparer.OrdinalIgnoreCase);
+                foreach (var kvp in headers)
+                {
+                    string name = kvp.Key.ToLowerInvariant();
+                    string value = kvp.Value;
+                    _cachedResponseHeaders[name] = value;
+                }
+            }
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestHeadDownloader.cs.meta

@@ -0,0 +1,11 @@
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+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestTextDownloader.cs

@@ -0,0 +1,52 @@
+using System;
+using UnityEngine.Networking;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// UnityWebRequest 文本下载器
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容解析为 UTF-8 文本字符串。
+    /// </remarks>
+    internal sealed class UnityWebRequestTextDownloader : UnityWebRequestDownloaderBase, IDownloadTextRequest
+    {
+        private readonly DownloadDataRequestArgs _args;
+
+        /// <summary>
+        /// 下载结果（文本字符串）
+        /// </summary>
+        public string Result { get; private set; }
+
+        /// <summary>
+        /// 构造文本下载器
+        /// </summary>
+        /// <param name="args">数据下载参数</param>
+        /// <param name="webRequestCreator">UnityWebRequest 创建器（可选）</param>
+        public UnityWebRequestTextDownloader(DownloadDataRequestArgs args, UnityWebRequestCreator webRequestCreator)
+            : base(args.URL, webRequestCreator)
+        {
+            _args = args;
+        }
+
+        /// <summary>
+        /// 创建 UnityWebRequest
+        /// </summary>
+        protected override void CreateWebRequest()
+        {
+            var handler = new DownloadHandlerBuffer();
+            _webRequest = CreateUnityWebRequestGet(URL);
+            _webRequest.downloadHandler = handler;
+            _webRequest.disposeDownloadHandlerOnDispose = true;
+            ApplyRequestOptions(_args.Timeout, _args.WatchdogTime, _args.Headers);
+        }
+
+        /// <summary>
+        /// 请求成功时的回调
+        /// </summary>
+        protected override void OnRequestSucceed()
+        {
+            Result = _webRequest.downloadHandler.text;
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/UnityWebRequestTextDownloader.cs.meta

@@ -0,0 +1,11 @@
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+  serializedVersion: 2
+  defaultReferences: []
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+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/VirtualFileDownloader.cs

@@ -0,0 +1,150 @@
+using System;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 模拟下载器
+    /// </summary>
+    /// <remarks>
+    /// 用于编辑器模式下模拟下载进度，不进行实际网络请求。
+    /// 根据配置的下载速度模拟进度变化。
+    /// </remarks>
+    internal sealed class VirtualFileDownloader : IDownloadFileRequest
+    {
+        private readonly DownloadSimulateRequestArgs _args;
+        private double _lastUpdateTime;
+
+        /// <summary>
+        /// 文件保存路径（模拟下载不需要）
+        /// </summary>
+        public string SavePath
+        {
+            get { return null; }
+        }
+
+        #region 接口实现
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        public string URL { get; }
+
+        /// <summary>
+        /// 是否完成
+        /// </summary>
+        public bool IsDone
+        {
+            get
+            {
+                PollingRequest();
+                return Status == EDownloadRequestStatus.Succeed
+                    || Status == EDownloadRequestStatus.Failed
+                    || Status == EDownloadRequestStatus.Aborted;
+            }
+        }
+
+        /// <summary>
+        /// 请求状态
+        /// </summary>
+        public EDownloadRequestStatus Status { get; private set; }
+
+        /// <summary>
+        /// 当前下载进度（0f - 1f）
+        /// </summary>
+        public float DownloadProgress { get; private set; }
+
+        /// <summary>
+        /// 当前请求已接收的字节数
+        /// </summary>
+        public long DownloadedBytes { get; private set; }
+
+        /// <summary>
+        /// HTTP 返回码（模拟固定返回 200）
+        /// </summary>
+        public long HttpCode { get; private set; }
+
+        /// <summary>
+        /// 错误信息
+        /// </summary>
+        public string Error { get; private set; }
+        #endregion
+
+        /// <summary>
+        /// 构造模拟下载器
+        /// </summary>
+        /// <param name="args">模拟下载参数</param>
+        public VirtualFileDownloader(DownloadSimulateRequestArgs args)
+        {
+            _args = args;
+            URL = args.URL;
+            Status = EDownloadRequestStatus.None;
+        }
+
+        /// <summary>
+        /// 发起请求
+        /// </summary>
+        public void SendRequest()
+        {
+            if (Status == EDownloadRequestStatus.None)
+            {
+                Status = EDownloadRequestStatus.Running;
+                _lastUpdateTime = GetUnityEngineRealtime();
+            }
+        }
+
+        /// <summary>
+        /// 轮询请求
+        /// </summary>
+        public void PollingRequest()
+        {
+            if (Status != EDownloadRequestStatus.Running)
+                return;
+
+            double currentTime = GetUnityEngineRealtime();
+            double deltaTime = currentTime - _lastUpdateTime;
+            _lastUpdateTime = currentTime;
+
+            // 计算本帧下载的字节数
+            long downloadBytes = (long)(_args.DownloadSpeed * deltaTime);
+            DownloadedBytes += downloadBytes;
+
+            if (_args.FileSize > 0)
+                DownloadProgress = (float)DownloadedBytes / _args.FileSize;
+
+            // 检查是否完成
+            if (DownloadedBytes >= _args.FileSize)
+            {
+                HttpCode = 200;
+                DownloadProgress = 1f;
+                DownloadedBytes = _args.FileSize;
+                Status = EDownloadRequestStatus.Succeed;
+            }
+        }
+
+        /// <summary>
+        /// 中止请求
+        /// </summary>
+        public void AbortRequest()
+        {
+            if (Status == EDownloadRequestStatus.None || Status == EDownloadRequestStatus.Running)
+            {
+                Status = EDownloadRequestStatus.Aborted;
+            }
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        public void Dispose()
+        {
+        }
+
+        private double GetUnityEngineRealtime()
+        {
+#if UNITY_2020_3_OR_NEWER
+            return UnityEngine.Time.realtimeSinceStartupAsDouble;
+#else
+            return UnityEngine.Time.realtimeSinceStartup;
+#endif
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DefaultDownloadRequest/VirtualFileDownloader.cs.meta

@@ -0,0 +1,11 @@
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Assets/YooAsset/Runtime/DownloadSystem/DownloadDefine.cs

@@ -1,118 +0,0 @@
-
-namespace YooAsset
-{
-    /// <summary>
-    /// 下载器结束
-    /// </summary>
-    public struct DownloaderFinishData
-    {
-        /// <summary>
-        /// 所属包裹名称
-        /// </summary>
-        public string PackageName;
-
-        /// <summary>
-        /// 是否成功
-        /// </summary>
-        public bool Succeed;
-    }
-
-    /// <summary>
-    /// 下载器相关的更新数据
-    /// </summary>
-    public struct DownloadUpdateData
-    {
-        /// <summary>
-        /// 所属包裹名称
-        /// </summary>
-        public string PackageName;
-
-        /// <summary>
-        /// 下载进度 (0-1f)
-        /// </summary>
-        public float Progress;
-
-        /// <summary>
-        /// 下载文件总数
-        /// </summary>
-        public int TotalDownloadCount;
-
-        /// <summary>
-        /// 当前完成的下载文件数量
-        /// </summary>
-        public int CurrentDownloadCount;
-
-        /// <summary>
-        /// 下载数据总大小（单位：字节）
-        /// </summary>
-        public long TotalDownloadBytes;
-
-        /// <summary>
-        /// 当前完成的下载数据大小（单位：字节）
-        /// </summary>
-        public long CurrentDownloadBytes;
-    }
-
-    /// <summary>
-    /// 下载器相关的错误数据
-    /// </summary>
-    public struct DownloadErrorData
-    {
-        /// <summary>
-        /// 所属包裹名称
-        /// </summary>
-        public string PackageName;
-
-        /// <summary>
-        /// 下载失败的文件名称
-        /// </summary>
-        public string FileName;
-
-        /// <summary>
-        /// 错误信息
-        /// </summary>
-        public string ErrorInfo;
-    }
-
-    /// <summary>
-    /// 下载器相关的文件数据
-    /// </summary>
-    public struct DownloadFileData
-    {
-        /// <summary>
-        /// 所属包裹名称
-        /// </summary>
-        public string PackageName;
-
-        /// <summary>
-        /// 下载的文件名称
-        /// </summary>
-        public string FileName;
-
-        /// <summary>
-        /// 下载的文件大小
-        /// </summary>
-        public long FileSize;
-    }
-
-    /// <summary>
-    /// 导入文件的信息
-    /// </summary>
-    public struct ImportFileInfo
-    {
-        /// <summary>
-        /// 本地文件路径
-        /// </summary>
-        public string FilePath;
-
-        /// <summary>
-        /// 资源包名称
-        /// </summary>
-        public string BundleName;
-
-        /// <summary>
-        /// 资源包GUID
-        /// </summary>
-        public string BundleGUID;
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/DownloadSystemDefine.cs

@@ -0,0 +1,443 @@
+using System.Collections.Generic;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 下载器结束
+    /// </summary>
+    public struct DownloaderFinishData
+    {
+        /// <summary>
+        /// 所属包裹名称
+        /// </summary>
+        public string PackageName;
+
+        /// <summary>
+        /// 是否成功
+        /// </summary>
+        public bool Succeed;
+    }
+
+    /// <summary>
+    /// 下载器相关的更新数据
+    /// </summary>
+    public struct DownloadUpdateData
+    {
+        /// <summary>
+        /// 所属包裹名称
+        /// </summary>
+        public string PackageName;
+
+        /// <summary>
+        /// 下载进度 (0-1f)
+        /// </summary>
+        public float Progress;
+
+        /// <summary>
+        /// 下载文件总数
+        /// </summary>
+        public int TotalDownloadCount;
+
+        /// <summary>
+        /// 当前完成的下载文件数量
+        /// </summary>
+        public int CurrentDownloadCount;
+
+        /// <summary>
+        /// 下载数据总大小（单位：字节）
+        /// </summary>
+        public long TotalDownloadBytes;
+
+        /// <summary>
+        /// 当前完成的下载数据大小（单位：字节）
+        /// </summary>
+        public long CurrentDownloadBytes;
+    }
+
+    /// <summary>
+    /// 下载器相关的错误数据
+    /// </summary>
+    public struct DownloadErrorData
+    {
+        /// <summary>
+        /// 所属包裹名称
+        /// </summary>
+        public string PackageName;
+
+        /// <summary>
+        /// 下载失败的文件名称
+        /// </summary>
+        public string FileName;
+
+        /// <summary>
+        /// 错误信息
+        /// </summary>
+        public string ErrorInfo;
+    }
+
+    /// <summary>
+    /// 下载器相关的文件数据
+    /// </summary>
+    public struct DownloadFileData
+    {
+        /// <summary>
+        /// 所属包裹名称
+        /// </summary>
+        public string PackageName;
+
+        /// <summary>
+        /// 下载的文件名称
+        /// </summary>
+        public string FileName;
+
+        /// <summary>
+        /// 下载的文件大小
+        /// </summary>
+        public long FileSize;
+    }
+
+    /// <summary>
+    /// 导入文件的信息
+    /// </summary>
+    public struct ImportFileInfo
+    {
+        /// <summary>
+        /// 本地文件路径
+        /// </summary>
+        public string FilePath;
+
+        /// <summary>
+        /// 资源包名称
+        /// </summary>
+        public string BundleName;
+
+        /// <summary>
+        /// 资源包GUID
+        /// </summary>
+        public string BundleGUID;
+    }
+
+
+    /// <summary>
+    /// 下载请求状态
+    /// </summary>
+    internal enum EDownloadRequestStatus
+    {
+        /// <summary>
+        /// 未开始
+        /// </summary>
+        None,
+
+        /// <summary>
+        /// 进行中
+        /// </summary>
+        Running,
+
+        /// <summary>
+        /// 已成功
+        /// </summary>
+        Succeed,
+
+        /// <summary>
+        /// 已失败
+        /// </summary>
+        Failed,
+
+        /// <summary>
+        /// 已中止
+        /// </summary>
+        Aborted,
+    }
+
+    /// <summary>
+    /// 文件下载请求参数
+    /// </summary>
+    /// <remarks>
+    /// 用于将下载内容保存到本地文件的请求配置。
+    /// 支持断点续传和追加写入模式。
+    /// </remarks>
+    internal struct DownloadFileRequestArgs
+    {
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        public readonly string URL;
+
+        /// <summary>
+        /// 响应的超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 当 Timeout 设置为 0 时，不应用超时。
+        /// 设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
+        /// </remarks>
+        public readonly int Timeout;
+
+        /// <summary>
+        /// 看门狗超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 用于监控下载任务的数据接收情况。
+        /// 规则说明：
+        /// 1. 当设置值为 0 时，表示禁用看门狗监控。
+        /// 2. 每次接收到下载数据时，看门狗计时器会重置。
+        /// 3. 若在设定的时间范围内未收到任何数据，任务将被自动终止。
+        /// </remarks>
+        public readonly int WatchdogTime;
+
+        /// <summary>
+        /// 文件保存路径
+        /// </summary>
+        public readonly string SavePath;
+
+        /// <summary>
+        /// 是否追加写入文件
+        /// </summary>
+        /// <remarks>
+        /// 配合 ResumeFromBytes 使用，用于断点续传场景。
+        /// </remarks>
+        public readonly bool AppendToFile;
+
+        /// <summary>
+        /// 中止请求时是否删除目标文件
+        /// </summary>
+        public readonly bool RemoveFileOnAbort;
+
+        /// <summary>
+        /// 断点续传的起始字节（小于等于 0 表示不启用）
+        /// </summary>
+        /// <remarks>
+        /// 推荐由后端自动设置 Range 请求头："bytes={ResumeFromBytes}-"。
+        /// </remarks>
+        public readonly long ResumeFromBytes;
+
+        /// <summary>
+        /// 自定义请求头（可选）
+        /// </summary>
+        public Dictionary<string, string> Headers;
+
+        /// <summary>
+        /// 构造文件下载请求参数
+        /// </summary>
+        public DownloadFileRequestArgs(
+            string url,
+            string savePath,
+            int timeout,
+            int watchdogTime,
+            bool appendToFile = false,
+            bool removeFileOnAbort = true,
+            long resumeFromBytes = 0)
+        {
+            URL = url;
+            SavePath = savePath;
+            Timeout = timeout;
+            WatchdogTime = watchdogTime;
+            AppendToFile = appendToFile;
+            RemoveFileOnAbort = removeFileOnAbort;
+            ResumeFromBytes = resumeFromBytes;
+            Headers = null;
+        }
+
+        /// <summary>
+        /// 添加请求头数据
+        /// </summary>
+        public void AddRequestHeader(string name, string value)
+        {
+            if (Headers == null)
+                Headers = new Dictionary<string, string>(10);
+            Headers.Add(name, value);
+        }
+    }
+
+    /// <summary>
+    /// 数据下载请求参数（通用）
+    /// </summary>
+    /// <remarks>
+    /// 用于下载到内存的请求配置。
+    /// 可用于字节数组（bytes）或文本（text）下载。
+    /// </remarks>
+    internal struct DownloadDataRequestArgs
+    {
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        public readonly string URL;
+
+        /// <summary>
+        /// 响应的超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 当 Timeout 设置为 0 时，不应用超时。
+        /// 设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
+        /// </remarks>
+        public readonly int Timeout;
+
+        /// <summary>
+        /// 看门狗超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 用于监控下载任务的数据接收情况。
+        /// 规则说明：
+        /// 1. 当设置值为 0 时，表示禁用看门狗监控。
+        /// 2. 每次接收到下载数据时，看门狗计时器会重置。
+        /// 3. 若在设定的时间范围内未收到任何数据，任务将被自动终止。
+        /// </remarks>
+        public readonly int WatchdogTime;
+
+        /// <summary>
+        /// 自定义请求头（可选）
+        /// </summary>
+        public Dictionary<string, string> Headers;
+
+        /// <summary>
+        /// 构造数据下载请求参数
+        /// </summary>
+        /// <param name="url">请求地址</param>
+        /// <param name="options">通用请求参数</param>
+        public DownloadDataRequestArgs(string url, int timeout, int watchdogTime)
+        {
+            URL = url;
+            Timeout = timeout;
+            WatchdogTime = watchdogTime;
+            Headers = null;
+        }
+
+        /// <summary>
+        /// 添加请求头数据
+        /// </summary>
+        public void AddRequestHeader(string name, string value)
+        {
+            if (Headers == null)
+                Headers = new Dictionary<string, string>(10);
+            Headers.Add(name, value);
+        }
+    }
+
+    /// <summary>
+    /// AssetBundle 下载请求参数
+    /// </summary>
+    /// <remarks>
+    /// 用于下载并加载 Unity AssetBundle 的请求配置。
+    /// 支持 Unity 内置缓存机制和 CRC 校验。
+    /// </remarks>
+    internal struct DownloadAssetBundleRequestArgs
+    {
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        public readonly string URL;
+
+        /// <summary>
+        /// 响应的超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 当 Timeout 设置为 0 时，不应用超时。
+        /// 设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
+        /// </remarks>
+        public readonly int Timeout;
+
+        /// <summary>
+        /// 看门狗超时时间（单位：秒）
+        /// </summary>
+        /// <remarks>
+        /// 用于监控下载任务的数据接收情况。
+        /// 规则说明：
+        /// 1. 当设置值为 0 时，表示禁用看门狗监控。
+        /// 2. 每次接收到下载数据时，看门狗计时器会重置。
+        /// 3. 若在设定的时间范围内未收到任何数据，任务将被自动终止。
+        /// </remarks>
+        public readonly int WatchdogTime;
+
+        /// <summary>
+        /// 禁用 Unity 的网络缓存
+        /// </summary>
+        public readonly bool DisableUnityWebCache;
+
+        /// <summary>
+        /// AssetBundle 文件哈希（用于 UnityWebRequest 的缓存）
+        /// </summary>
+        /// <remarks>
+        /// 仅当 DisableUnityWebCache 为 false 时需要。
+        /// </remarks>
+        public readonly string FileHash;
+
+        /// <summary>
+        /// Unity CRC 校验值
+        /// </summary>
+        public readonly uint UnityCRC;
+
+        /// <summary>
+        /// 自定义请求头（可选）
+        /// </summary>
+        public Dictionary<string, string> Headers;
+
+        /// <summary>
+        /// 构造 AssetBundle 下载请求参数
+        /// </summary>
+        public DownloadAssetBundleRequestArgs(
+            string url,
+            int timeout,
+            int watchdogTime,
+            bool disableUnityWebCache = true,
+            string fileHash = null,
+            uint unityCrc = 0)
+        {
+            URL = url;
+            Timeout = timeout;
+            WatchdogTime = watchdogTime;
+            DisableUnityWebCache = disableUnityWebCache;
+            FileHash = fileHash;
+            UnityCRC = unityCrc;
+            Headers = null;
+        }
+
+        /// <summary>
+        /// 添加请求头数据
+        /// </summary>
+        public void AddRequestHeader(string name, string value)
+        {
+            if (Headers == null)
+                Headers = new Dictionary<string, string>(10);
+            Headers.Add(name, value);
+        }
+    }
+
+    /// <summary>
+    /// 模拟下载请求参数
+    /// </summary>
+    /// <remarks>
+    /// 用于编辑器模式下模拟下载进度，不进行实际网络请求。
+    /// </remarks>
+    internal struct DownloadSimulateRequestArgs
+    {
+        /// <summary>
+        /// 请求地址（仅用于标识）
+        /// </summary>
+        public readonly string URL;
+
+        /// <summary>
+        /// 模拟的文件大小（字节）
+        /// </summary>
+        public readonly long FileSize;
+
+        /// <summary>
+        /// 模拟的下载速度（字节/秒）
+        /// </summary>
+        /// <remarks>
+        /// 用于计算模拟的下载进度。
+        /// </remarks>
+        public readonly long DownloadSpeed;
+
+        /// <summary>
+        /// 构造模拟下载请求参数
+        /// </summary>
+        /// <param name="url">请求地址（仅用于标识）</param>
+        /// <param name="fileSize">模拟的文件大小（字节）</param>
+        /// <param name="downloadSpeed">模拟的下载速度（字节/秒），默认 1MB/s</param>
+        public DownloadSimulateRequestArgs(string url, long fileSize, long downloadSpeed = 1024 * 1024)
+        {
+            URL = url;
+            FileSize = fileSize;
+            DownloadSpeed = downloadSpeed > 0 ? downloadSpeed : 1024 * 1024;
+        }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/DownloadSystemDefine.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: eb0480e877454f7c944f66a01646b6d4
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/DownloadSystemHelper.cs

@@ -3,32 +3,8 @@ using UnityEngine;
 
 namespace YooAsset
 {
-    /// <summary>
-    /// 自定义下载器的请求委托
-    /// </summary>
-    public delegate UnityWebRequest UnityWebRequestDelegate(string url);
-
     internal class DownloadSystemHelper
     {
-#if UNITY_EDITOR
-        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.SubsystemRegistration)]
-        private static void OnRuntimeInitialize()
-        {
-            UnityWebRequestCreater = null;
-        }
-#endif
-
-        public static UnityWebRequestDelegate UnityWebRequestCreater = null;
-        public static UnityWebRequest NewUnityWebRequestGet(string requestURL)
-        {
-            UnityWebRequest webRequest;
-            if (UnityWebRequestCreater != null)
-                webRequest = UnityWebRequestCreater.Invoke(requestURL);
-            else
-                webRequest = new UnityWebRequest(requestURL, UnityWebRequest.kHttpVerbGET);
-            return webRequest;
-        }
-
         /// <summary>
         /// 获取WWW加载本地资源的路径
         /// </summary>
@@ -81,7 +57,7 @@ namespace YooAsset
 #elif UNITY_STANDALONE_LINUX
             url = StringUtility.Format("file:///root/{0}", path);
 #else
-            throw new System.NotImplementedException();
+            throw new System.NotSupportedException($"[{nameof(DownloadSystemHelper.ConvertToWWWPath)}] not implemented platform: {UnityEngine.Application.platform}");
 #endif
 
             // For some special cases when users have special characters in their devices, url paths can not be identified correctly.
@@ -94,8 +70,12 @@ namespace YooAsset
         public static bool IsRequestLocalFile(string url)
         {
             //TODO UNITY_STANDALONE_OSX平台目前无法确定
+
+            // 本地文件传输协议
             if (url.StartsWith("file:"))
                 return true;
+
+            // JAR文件协议
             if (url.StartsWith("jar:file:"))
                 return true;
 

Assets/YooAsset/Runtime/DownloadSystem/Interface.meta

@@ -1,5 +1,5 @@
 fileFormatVersion: 2
-guid: 4630dac2050606043bb146325fdce6ad
+guid: d724672f4d6f24b4db435d10eef6c40d
 folderAsset: yes
 DefaultImporter:
   externalObjects: {}

Assets/YooAsset/Runtime/DownloadSystem/Interface/IDownloadBackend.cs

@@ -0,0 +1,78 @@
+using System;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 下载后台接口
+    /// </summary>
+    /// <remarks>
+    /// 不同网络库（UnityWebRequest / BestHTTP / 自研）实现该接口，用于创建具体下载请求。
+    /// 每个后台实例是独立的，不共享全局状态。
+    /// </remarks>
+    internal interface IDownloadBackend : IDisposable
+    {
+        /// <summary>
+        /// 后台名称（用于日志与调试）
+        /// </summary>
+        string Name { get; }
+
+        /// <summary>
+        /// 驱动更新
+        /// </summary>
+        /// <remarks>
+        /// 部分第三方网络库需要在 Unity 主线程中周期性调用 Update 进行驱动。
+        /// 不需要驱动的后台可实现为空方法。
+        /// </remarks>
+        void Update();
+
+        /// <summary>
+        /// 创建 HEAD 请求
+        /// </summary>
+        /// <remarks>
+        /// 仅获取响应头信息，不下载实际内容。
+        /// 用于检查资源是否存在、获取资源大小、检查缓存有效性等场景。
+        /// </remarks>
+        /// <param name="args">数据请求参数</param>
+        /// <returns>HEAD 请求实例</returns>
+        IDownloadHeadRequest CreateHeadRequest(DownloadDataRequestArgs args);
+
+        /// <summary>
+        /// 创建文件下载请求
+        /// </summary>
+        /// <param name="args">文件下载参数</param>
+        /// <returns>文件下载请求实例</returns>
+        IDownloadFileRequest CreateFileRequest(DownloadFileRequestArgs args);
+
+        /// <summary>
+        /// 创建内存下载请求（字节数组）
+        /// </summary>
+        /// <param name="args">数据下载参数</param>
+        /// <returns>字节下载请求实例</returns>
+        IDownloadBytesRequest CreateBytesRequest(DownloadDataRequestArgs args);
+
+        /// <summary>
+        /// 创建文本下载请求
+        /// </summary>
+        /// <param name="args">数据下载参数</param>
+        /// <returns>文本下载请求实例</returns>
+        IDownloadTextRequest CreateTextRequest(DownloadDataRequestArgs args);
+
+        /// <summary>
+        /// 创建 AssetBundle 下载请求
+        /// </summary>
+        /// <param name="args">AssetBundle 下载参数</param>
+        /// <returns>AssetBundle 下载请求实例</returns>
+        IDownloadAssetBundleRequest CreateAssetBundleRequest(DownloadAssetBundleRequestArgs args);
+
+        /// <summary>
+        /// 创建模拟下载请求
+        /// </summary>
+        /// <remarks>
+        /// 用于编辑器模式下模拟下载进度，不进行实际网络请求。
+        /// 可用于测试下载流程和 UI 展示。
+        /// </remarks>
+        /// <param name="args">模拟下载参数</param>
+        /// <returns>模拟下载请求实例</returns>
+        IDownloadFileRequest CreateSimulateRequest(DownloadSimulateRequestArgs args);
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/Interface/IDownloadBackend.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: e88c026ebbfb40258aad52ad1c2feb70
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/Interface/IDownloadRequest.cs

@@ -0,0 +1,194 @@
+using System;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 可轮询的下载请求接口
+    /// </summary>
+    /// <remarks>
+    /// 上层通常会在每帧轮询 Status IsDone，并在完成后读取结果。
+    /// </remarks>
+    internal interface IDownloadRequest : IDisposable
+    {
+        /// <summary>
+        /// 请求地址
+        /// </summary>
+        string URL { get; }
+
+        /// <summary>
+        /// 是否完成（成功/失败/中止）
+        /// </summary>
+        bool IsDone { get; }
+
+        /// <summary>
+        /// 请求状态
+        /// </summary>
+        EDownloadRequestStatus Status { get; }
+
+        /// <summary>
+        /// 当前下载进度（0f - 1f）
+        /// </summary>
+        /// <remarks>
+        /// 部分情况下无法准确获取总长度，可返回 0。
+        /// </remarks>
+        float DownloadProgress { get; }
+
+        /// <summary>
+        /// 当前请求已接收的字节数
+        /// </summary>
+        /// <remarks>
+        /// 断点续传场景下，该值仅表示"本次请求新增下载的字节数"，不包含已存在的本地文件长度。
+        /// </remarks>
+        long DownloadedBytes { get; }
+
+        /// <summary>
+        /// HTTP 返回码
+        /// </summary>
+        /// <remarks>
+        /// 非 HTTP 协议可返回 0。使用 long 类型以兼容各种协议的返回码。
+        /// </remarks>
+        long HttpCode { get; }
+
+        /// <summary>
+        /// 错误信息
+        /// </summary>
+        /// <remarks>
+        /// 失败时不为空。
+        /// </remarks>
+        string Error { get; }
+
+        /// <summary>
+        /// 发起请求
+        /// </summary>
+        void SendRequest();
+
+        /// <summary>
+        /// 轮询请求
+        /// </summary>
+        void PollingRequest();
+
+        /// <summary>
+        /// 中止请求
+        /// </summary>
+        void AbortRequest();
+    }
+
+    /// <summary>
+    /// HEAD 请求接口（仅获取响应头）
+    /// </summary>
+    /// <remarks>
+    /// 用于检查资源是否存在、获取资源大小、检查缓存有效性等场景。
+    /// 不下载实际内容，仅获取响应头信息。
+    /// </remarks>
+    internal interface IDownloadHeadRequest : IDownloadRequest
+    {
+        /// <summary>
+        /// 获取 ETag 响应头
+        /// </summary>
+        /// <remarks>
+        /// 用于缓存验证，如果服务器未返回则为 null。
+        /// </remarks>
+        string ETag { get; }
+
+        /// <summary>
+        /// 获取 Last-Modified 响应头
+        /// </summary>
+        /// <remarks>
+        /// 资源最后修改时间，如果服务器未返回则为 null。
+        /// </remarks>
+        string LastModified { get; }
+
+        /// <summary>
+        /// 获取 Content-Type 响应头
+        /// </summary>
+        /// <remarks>
+        /// 资源的 MIME 类型，如果服务器未返回则为 null。
+        /// </remarks>
+        string ContentType { get; }
+
+        /// <summary>
+        /// 预期下载的总字节数（Content-Length）
+        /// </summary>
+        /// <remarks>
+        /// 从响应头 Content-Length 获取。
+        /// 如果服务器未返回或请求未完成，返回 -1。
+        /// 用于更准确的进度计算。
+        /// </remarks>
+        long ContentLength { get; }
+
+        /// <summary>
+        /// 获取响应头信息
+        /// </summary>
+        /// <param name="name">响应头名称（不区分大小写）</param>
+        /// <returns>响应头的值，如果不存在或请求未完成则返回 null</returns>
+        /// <remarks>
+        /// 常用响应头：Content-Length、Content-Type、ETag、Last-Modified 等。
+        /// </remarks>
+        string GetResponseHeader(string name);
+    }
+
+    /// <summary>
+    /// 文件下载请求接口
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容保存到指定的本地文件路径。
+    /// </remarks>
+    internal interface IDownloadFileRequest : IDownloadRequest
+    {
+        /// <summary>
+        /// 文件保存路径
+        /// </summary>
+        string SavePath { get; }
+    }
+
+    /// <summary>
+    /// 内存下载请求接口（字节数组）
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容保存到内存中的字节数组。
+    /// </remarks>
+    internal interface IDownloadBytesRequest : IDownloadRequest
+    {
+        /// <summary>
+        /// 下载结果（字节数组）
+        /// </summary>
+        /// <remarks>
+        /// 仅在请求成功时可用，失败时为 null。
+        /// </remarks>
+        byte[] Result { get; }
+    }
+
+    /// <summary>
+    /// 文本下载请求接口
+    /// </summary>
+    /// <remarks>
+    /// 将下载内容解析为 UTF-8 文本字符串。
+    /// </remarks>
+    internal interface IDownloadTextRequest : IDownloadRequest
+    {
+        /// <summary>
+        /// 下载结果（文本字符串）
+        /// </summary>
+        /// <remarks>
+        /// 仅在请求成功时可用，失败时为 null。
+        /// </remarks>
+        string Result { get; }
+    }
+
+    /// <summary>
+    /// AssetBundle 下载请求接口
+    /// </summary>
+    /// <remarks>
+    /// 下载并加载 Unity AssetBundle 资源包。
+    /// </remarks>
+    internal interface IDownloadAssetBundleRequest : IDownloadRequest
+    {
+        /// <summary>
+        /// 下载结果（AssetBundle 对象）
+        /// </summary>
+        /// <remarks>
+        /// 仅在请求成功时可用，失败时为 null。
+        /// </remarks>
+        UnityEngine.AssetBundle Result { get; }
+    }
+}

Assets/YooAsset/Runtime/DownloadSystem/Interface/IDownloadRequest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 2a2aafeb309243f4959394a97d66b19f
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityAssetBundleRequestOperation.cs

@@ -1,113 +0,0 @@
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityAssetBundleRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            Done,
-        }
-
-        private UnityWebRequestAsyncOperation _requestOperation;
-        private DownloadHandlerAssetBundle _downloadhandler;
-        private readonly PackageBundle _packageBundle;
-        private readonly bool _disableUnityWebCache;
-        private ESteps _steps = ESteps.None;
-
-        /// <summary>
-        /// 请求结果
-        /// </summary>
-        public AssetBundle Result { private set; get; }
-
-        internal UnityAssetBundleRequestOperation(PackageBundle packageBundle, bool disableUnityWebCache, string url) : base(url)
-        {
-            _packageBundle = packageBundle;
-            _disableUnityWebCache = disableUnityWebCache;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.CreateRequest)
-            {
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = _requestOperation.progress;
-                if (_requestOperation.isDone == false)
-                    return;
-
-                if (CheckRequestResult())
-                {
-                    AssetBundle assetBundle = _downloadhandler.assetBundle;
-                    if (assetBundle == null)
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"URL : {_requestURL} Download handler asset bundle object is null !";
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Result = assetBundle;
-                        Status = EOperationStatus.Succeed;
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            _downloadhandler = CreateWebDownloadHandler();
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = _downloadhandler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _requestOperation = _webRequest.SendWebRequest();
-        }
-        private DownloadHandlerAssetBundle CreateWebDownloadHandler()
-        {
-            if (_disableUnityWebCache)
-            {
-                var downloadhandler = new DownloadHandlerAssetBundle(_requestURL, _packageBundle.UnityCRC);
-#if UNITY_2020_3_OR_NEWER
-                downloadhandler.autoLoadAssetBundle = false;
-#endif
-                return downloadhandler;
-            }
-            else
-            {
-                // 注意：优先从浏览器缓存里获取文件
-                // The file hash defining the version of the asset bundle.
-                Hash128 fileHash = Hash128.Parse(_packageBundle.FileHash);
-                var downloadhandler = new DownloadHandlerAssetBundle(_requestURL, fileHash, _packageBundle.UnityCRC);
-#if UNITY_2020_3_OR_NEWER
-                downloadhandler.autoLoadAssetBundle = false;
-#endif
-                return downloadhandler;
-            }
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityVirtualBundleRequestOperation.cs

@@ -1,65 +0,0 @@
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityVirtualBundleRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            Download,
-            Done,
-        }
-
-        private readonly PackageBundle _bundle;
-        private readonly int _downloadSpeed;
-        private ESteps _steps = ESteps.None;
-
-        internal UnityVirtualBundleRequestOperation(PackageBundle packageBundle, int downloadSpeed, string url) : base(url)
-        {
-            _bundle = packageBundle;
-            _downloadSpeed = downloadSpeed;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.Download;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.Download)
-            {
-                // 模拟下载进度
-                float progress = 0;
-                if (DownloadedBytes > 0)
-                    progress = DownloadedBytes / _bundle.FileSize;
-                long downloadBytes = (long)((double)_downloadSpeed * Time.deltaTime);
-                
-                Progress = progress;
-                DownloadProgress = progress;
-                DownloadedBytes += downloadBytes;
-                if (DownloadedBytes < _bundle.FileSize)
-                    return;
-
-                Progress = 1f;
-                DownloadProgress = 1f;
-                DownloadedBytes = _bundle.FileSize;
-
-                _steps = ESteps.Done;
-                Status = EOperationStatus.Succeed;
-            }
-        }
-        internal override void InternalWaitForAsyncComplete()
-        {
-            if (_steps != ESteps.Done)
-            {
-                _steps = ESteps.Done;
-                Status = EOperationStatus.Failed;
-                Error = $"Try load bundle {_bundle.BundleName} from remote !";
-            }
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebCacheRequestOperation.cs

@@ -1,89 +0,0 @@
-using System.Collections;
-using System.Collections.Generic;
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityWebCacheRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            Done,
-        }
-
-        private UnityWebRequestAsyncOperation _requestOperation;
-        private readonly Dictionary<string, string> _headers = new Dictionary<string, string>();
-        private ESteps _steps = ESteps.None;
-
-
-        internal UnityWebCacheRequestOperation(string url) : base(url)
-        {
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.CreateRequest)
-            {
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = _requestOperation.progress;
-                if (_requestOperation.isDone == false)
-                    return;
-
-                if (CheckRequestResult())
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Succeed;
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-        }
-
-        /// <summary>
-        /// 设置请求头信息
-        /// </summary>
-        public void SetRequestHeader(string name, string value)
-        {
-            _headers.Add(name, value);
-        }
-
-        private void CreateWebRequest()
-        {
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-
-            // 设置消息头
-            foreach (var keyValuePair in _headers)
-            {
-                string name = keyValuePair.Key;
-                string value = keyValuePair.Value;
-                _webRequest.SetRequestHeader(name, value);
-            }
-
-            _requestOperation = _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebDataRequestOperation.cs

@@ -1,96 +0,0 @@
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityWebDataRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            Done,
-        }
-
-        private UnityWebRequestAsyncOperation _requestOperation;
-        private ESteps _steps = ESteps.None;
-
-        /// <summary>
-        /// 响应的超时时间（单位：秒），在经过Timeout的秒数后尝试中止。
-        /// 注意：当Timeout设置为0时，不会应用超时。
-        /// 注意：设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
-        /// </summary>
-        private readonly int _timeout;
-
-        /// <summary>
-        /// 请求结果
-        /// </summary>
-        public byte[] Result { private set; get; }
-
-
-        internal UnityWebDataRequestOperation(string url, int timeout) : base(url)
-        {
-            _timeout = timeout;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.CreateRequest)
-            {
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = _requestOperation.progress;
-                if (_requestOperation.isDone == false)
-                    return;
-
-                if (CheckRequestResult())
-                {
-                    var fileData = _webRequest.downloadHandler.data;
-                    if (fileData == null || fileData.Length == 0)
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"URL : {_requestURL} Download handler data is null or empty !";
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Result = fileData;
-                        Status = EOperationStatus.Succeed;
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            DownloadHandlerBuffer handler = new DownloadHandlerBuffer();
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.timeout = _timeout;
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _requestOperation = _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebDataRequestOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: b7557eb146572de49a1ec9b3f3c0b706
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebFileRequestOperation.cs

@@ -1,83 +0,0 @@
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityWebFileRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            Done,
-        }
-
-        private UnityWebRequestAsyncOperation _requestOperation;
-        private readonly string _fileSavePath;
-        private ESteps _steps = ESteps.None;
-
-        /// <summary>
-        /// 响应的超时时间（单位：秒），在经过Timeout的秒数后尝试中止。
-        /// 注意：当Timeout设置为0时，不会应用超时。
-        /// 注意：设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
-        /// </summary>
-        private readonly int _timeout;
-
-
-        internal UnityWebFileRequestOperation(string url, string fileSavePath, int timeout) : base(url)
-        {
-            _fileSavePath = fileSavePath;
-            _timeout = timeout;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.CreateRequest)
-            {
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = _requestOperation.progress;
-                if (_requestOperation.isDone == false)
-                    return;
-
-                if (CheckRequestResult())
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Succeed;
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            DownloadHandlerFile handler = new DownloadHandlerFile(_fileSavePath);
-            handler.removeFileOnAbort = true;
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.timeout = _timeout;
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _requestOperation = _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebFileRequestOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 2ab5f2486d06e2642ba7aa9c9623430e
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebRequestOperation.cs

@@ -1,98 +0,0 @@
-using System;
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal abstract class UnityWebRequestOperation : AsyncOperationBase
-    {
-        protected UnityWebRequest _webRequest;
-        protected readonly string _requestURL;
-        private bool _isAbort = false;
-
-        /// <summary>
-        /// HTTP返回码
-        /// </summary>
-        public long HttpCode { private set; get; }
-
-        /// <summary>
-        /// 当前下载的字节数
-        /// </summary>
-        public long DownloadedBytes { protected set; get; }
-
-        /// <summary>
-        /// 当前下载进度（0f - 1f）
-        /// </summary>
-        public float DownloadProgress { protected set; get; }
-
-        /// <summary>
-        /// 请求的URL地址
-        /// </summary>
-        public string URL
-        {
-            get { return _requestURL; }
-        }
-
-        internal UnityWebRequestOperation(string url)
-        {
-            _requestURL = url;
-        }
-        internal override void InternalAbort()
-        {
-            //TODO
-            // 1. 编辑器下停止运行游戏的时候主动终止下载任务
-            // 2. 真机上销毁包裹的时候主动终止下载任务
-            if (_isAbort == false)
-            {
-                if (_webRequest != null)
-                {
-                    _webRequest.Abort();
-                    _isAbort = true;
-                }
-            }
-        }
-
-        /// <summary>
-        /// 释放下载器
-        /// </summary>
-        protected void DisposeRequest()
-        {
-            if (_webRequest != null)
-            {
-                //注意：引擎底层会自动调用Abort方法
-                _webRequest.Dispose();
-                _webRequest = null;
-            }
-        }
-
-        /// <summary>
-        /// 检测请求结果
-        /// </summary>
-        protected bool CheckRequestResult()
-        {
-            HttpCode = _webRequest.responseCode;
-
-#if UNITY_2020_3_OR_NEWER
-            if (_webRequest.result != UnityWebRequest.Result.Success)
-            {
-                Error = $"URL : {_requestURL} Error : {_webRequest.error}";
-                return false;
-            }
-            else
-            {
-                return true;
-            }
-#else
-            if (_webRequest.isNetworkError || _webRequest.isHttpError)
-            {
-                Error = $"URL : {_requestURL} Error : {_webRequest.error}";
-                return false;
-            }
-            else
-            {
-                return true;
-            }
-#endif
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebRequestOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 4e5c3c1a1655a8b41b585c6811201583
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebTextRequestOperation.cs

@@ -1,96 +0,0 @@
-using UnityEngine.Networking;
-using UnityEngine;
-
-namespace YooAsset
-{
-    internal class UnityWebTextRequestOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            Done,
-        }
-
-        private UnityWebRequestAsyncOperation _requestOperation;
-        private ESteps _steps = ESteps.None;
-
-        /// <summary>
-        /// 响应的超时时间（单位：秒），在经过Timeout的秒数后尝试中止。
-        /// 注意：当Timeout设置为0时，不会应用超时。
-        /// 注意：设置的超时值可能应用于Android上的每个URL重定向，这可能会导致响应时间增加。
-        /// </summary>
-        private readonly int _timeout;
-
-        /// <summary>
-        /// 请求结果
-        /// </summary>
-        public string Result { private set; get; }
-
-
-        internal UnityWebTextRequestOperation(string url, int timeout) : base(url)
-        {
-            _timeout = timeout;
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            if (_steps == ESteps.CreateRequest)
-            {
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = _requestOperation.progress;
-                if (_requestOperation.isDone == false)
-                    return;
-
-                if (CheckRequestResult())
-                {
-                    var fileText = _webRequest.downloadHandler.text;
-                    if (string.IsNullOrEmpty(fileText))
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"URL : {_requestURL} Download handler text is null or empty !";
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Result = fileText;
-                        Status = EOperationStatus.Succeed;
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            DownloadHandlerBuffer handler = new DownloadHandlerBuffer();
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.timeout = _timeout;
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _requestOperation = _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/DownloadSystem/Operation/Internal/UnityWebTextRequestOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: a488de5dcd6f4c448a47c4b574d5c9bc
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/README.md

@@ -0,0 +1,567 @@
+# DownloadSystem 下载模块
+
+## 模块概述
+
+DownloadSystem 是 YooAsset 资源管理系统的**底层网络下载层**，负责处理所有 HTTP 网络请求。该模块提供了统一的下载接口抽象，支持文件下载、断点续传、并发请求（由上层调度）、看门狗监控等功能。
+
+### 核心职责
+
+- HTTP/HTTPS 文件下载
+- 断点续传支持
+- 看门狗超时保护
+- 多种下载类型（文件/字节/文本/AssetBundle）
+- 可插拔的网络库后端
+
+---
+
+## 边界与上层协作
+
+DownloadSystem 的职责是提供“可替换后端 + 统一请求接口 + 轮询式生命周期”的基础能力：
+
+- **本模块不负责并发队列/限流调度**：并发通常由上层同时创建多个 request 并自行控制并发数。
+- **本模块不负责重试/回退策略**：失败后的重试、切换 CDN、降级等策略通常由上层系统实现。
+- **本模块不负责持久化下载任务**：断点续传依赖本地已有文件与 `Range` 请求头，并由上层管理断点信息。
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **可扩展性** | 支持可插拔的网络库后端（UnityWebRequest/BestHTTP/自研） |
+| **鲁棒性** | 看门狗超时保护、自动清理失败文件、完整错误信息 |
+| **高性能** | 轮询模式无阻塞、支持并发请求（并发数由上层调度） |
+| **易用性** | 流畅的参数构建 API、清晰的状态转换 |
+
+---
+
+## 架构概念
+
+### 分层架构
+
+```
+┌─────────────────────────────────────────────────────────┐
+│                    上层调用者                            │
+│              (FileSystem / ResourceManager)              │
+└─────────────────────────┬───────────────────────────────┘
+                          │
+┌─────────────────────────▼───────────────────────────────┐
+│                  IDownloadBackend                        │
+│                    (后端接口)                            │
+│         定义网络库合约，工厂模式创建请求                   │
+└─────────────────────────┬───────────────────────────────┘
+                          │
+┌─────────────────────────▼───────────────────────────────┐
+│                  IDownloadRequest                        │
+│                    (请求接口)                            │
+│           轮询式生命周期管理，状态机驱动                   │
+└─────────────────────────┬───────────────────────────────┘
+                          │
+┌─────────────────────────▼───────────────────────────────┐
+│              UnityWebRequest / 其他网络库                 │
+│                    (底层实现)                            │
+└─────────────────────────────────────────────────────────┘
+```
+
+### 核心组件
+
+- **后端层 (IDownloadBackend)**: 定义网络库实现合约，通过工厂方法创建各类请求
+- **请求层 (IDownloadRequest)**: 统一的请求生命周期管理，支持轮询驱动
+- **参数层 (Args 结构体)**: 配置下载行为（超时、断点续传、看门狗等）
+
+---
+
+## 文件结构
+
+```
+DownloadSystem/
+├── Interface/                                # 接口定义
+│   ├── IDownloadBackend.cs                   # 后端接口（工厂模式）
+│   └── IDownloadRequest.cs                   # 请求接口层次结构
+│
+├── DefaultDownloadBackend/                   # 默认后端实现
+│   ├── UnityWebRequestBackend.cs             # UnityWebRequest 后端
+│   └── UnityWebRequestCreator.cs             # UnityWebRequest 创建委托
+│
+├── DefaultDownloadRequest/                   # 默认请求实现
+│   ├── UnityWebRequestDownloaderBase.cs      # 基础下载器（抽象类）
+│   ├── UnityWebRequestFileDownloader.cs      # 文件下载器
+│   ├── UnityWebRequestHeadDownloader.cs      # HEAD 请求器
+│   ├── UnityWebRequestBytesDownloader.cs     # 字节下载器
+│   ├── UnityWebRequestTextDownloader.cs      # 文本下载器
+│   ├── UnityWebRequestAssetBundleDownloader.cs # AssetBundle 下载器
+│   └── VirtualFileDownloader.cs              # 模拟下载器（编辑器用）
+│
+├── DownloadSystemDefine.cs                   # 枚举、结构体定义
+├── DownloadSystemHelper.cs                   # 工具函数
+└── WebRequestCounter.cs                      # 请求失败计数器
+```
+
+---
+
+## 接口说明
+
+### IDownloadBackend（后端接口）
+
+定义网络库实现的合约，通过工厂方法创建各类下载请求。
+
+```csharp
+public interface IDownloadBackend
+{
+    /// <summary>
+    /// 后端标识名称（用于日志/调试）
+    /// </summary>
+    string Name { get; }
+
+    /// <summary>
+    /// 定期驱动更新（部分第三方库需要）
+    /// </summary>
+    void Update();
+
+    // 工厂方法 - 创建各类请求
+    IDownloadHeadRequest CreateHeadRequest(DownloadDataRequestArgs args);
+    IDownloadFileRequest CreateFileRequest(DownloadFileRequestArgs args);
+    IDownloadBytesRequest CreateBytesRequest(DownloadDataRequestArgs args);
+    IDownloadTextRequest CreateTextRequest(DownloadDataRequestArgs args);
+    IDownloadAssetBundleRequest CreateAssetBundleRequest(DownloadAssetBundleRequestArgs args);
+    IDownloadFileRequest CreateSimulateRequest(DownloadSimulateRequestArgs args);
+}
+```
+
+### IDownloadRequest（基础请求接口）
+
+所有下载请求的通用接口，定义生命周期和状态管理。
+
+```csharp
+public interface IDownloadRequest : IDisposable
+{
+    // 元信息
+    string URL { get; }
+
+    // 生命周期
+    bool IsDone { get; }                      // 每次访问自动轮询
+    EDownloadRequestStatus Status { get; }
+
+    // 进度跟踪
+    float DownloadProgress { get; }           // 0f - 1f
+    long DownloadedBytes { get; }             // 本次请求新增字节数
+
+    // 诊断信息
+    long HttpCode { get; }
+    string Error { get; }
+
+    // 生命周期方法
+    void SendRequest();                       // 发起请求
+    void PollingRequest();                    // 轮询状态
+    void AbortRequest();                      // 中止请求
+}
+```
+
+### 专化请求接口
+
+| 接口 | 用途 | 特有属性 |
+|------|------|----------|
+| `IDownloadHeadRequest` | HEAD 请求，获取响应头 | `ETag`, `LastModified`, `ContentLength`, `ContentType` |
+| `IDownloadFileRequest` | 文件下载到本地 | `SavePath` |
+| `IDownloadBytesRequest` | 下载到内存（字节数组） | `byte[] Result` |
+| `IDownloadTextRequest` | 下载文本内容 | `string Result` |
+| `IDownloadAssetBundleRequest` | 下载并加载 AssetBundle | `AssetBundle Result` |
+
+---
+
+## 结构体定义
+
+### 请求状态枚举
+
+```csharp
+public enum EDownloadRequestStatus
+{
+    None,       // 未开始
+    Running,    // 进行中
+    Succeed,    // 已成功
+    Failed,     // 已失败
+    Aborted     // 已中止（用户中止或看门狗超时）
+}
+```
+
+### 请求参数结构体
+
+#### DownloadFileRequestArgs（文件下载参数）
+
+```csharp
+public struct DownloadFileRequestArgs
+{
+    public string URL;                    // 请求地址
+    public int Timeout;                   // 响应超时（秒），0=无限制
+    public int WatchdogTime;              // 看门狗超时（秒）
+
+    public string SavePath;               // 文件保存路径
+    public bool AppendToFile;             // 追加写入（断点续传）
+    public bool RemoveFileOnAbort;        // 中止时删除文件
+    public long ResumeFromBytes;          // 断点续传起始位置
+
+    public Dictionary<string, string> Headers;  // 自定义请求头
+}
+```
+
+#### DownloadDataRequestArgs（数据下载参数）
+
+```csharp
+public struct DownloadDataRequestArgs
+{
+    public string URL;                    // 请求地址
+    public int Timeout;                   // 响应超时（秒）
+    public int WatchdogTime;              // 看门狗超时（秒）
+    public Dictionary<string, string> Headers;  // 自定义请求头
+}
+```
+
+#### DownloadAssetBundleRequestArgs（AssetBundle 下载参数）
+
+```csharp
+public struct DownloadAssetBundleRequestArgs
+{
+    public string URL;                    // 请求地址
+    public int Timeout;                   // 响应超时
+    public int WatchdogTime;              // 看门狗超时
+
+    public bool DisableUnityWebCache;     // 禁用 Unity 缓存（推荐 true）
+    public string FileHash;               // 文件哈希（缓存启用时需要）
+    public uint UnityCRC;                 // Unity CRC 校验值
+
+    public Dictionary<string, string> Headers;
+}
+```
+
+#### DownloadSimulateRequestArgs（模拟下载参数）
+
+```csharp
+public struct DownloadSimulateRequestArgs
+{
+    public string URL;            // 标识符
+    public long FileSize;         // 模拟文件大小
+    public long DownloadSpeed;    // 模拟速度（字节/秒），默认 1MB/s
+}
+```
+
+### 回调数据结构体
+
+| 结构体 | 用途 | 关键字段 |
+|--------|------|----------|
+| `DownloaderFinishData` | 下载完成回调 | `PackageName`, `Succeed` |
+| `DownloadUpdateData` | 进度更新回调 | `Progress`, `TotalDownloadBytes`, `CurrentDownloadBytes` |
+| `DownloadErrorData` | 下载错误回调 | `FileName`, `ErrorInfo` |
+| `DownloadFileData` | 文件完成回调 | `FileName`, `FileSize` |
+| `ImportFileInfo` | 导入文件元数据 | `FilePath`, `BundleName`, `BundleGUID` |
+
+---
+
+## 核心类说明
+
+### UnityWebRequestBackend
+
+默认的后端实现，基于 Unity 的 UnityWebRequest API。
+
+**特性：**
+- 支持自定义 UnityWebRequest 创建方式（证书验证、代理等）
+- 无需手动调用 Update()，UnityWebRequest 自动驱动
+
+```csharp
+// 自定义 UnityWebRequest 创建（建议通过 backend 构造函数传入）
+UnityWebRequestCreator creator = (url, method) =>
+{
+    var request = new UnityWebRequest(url, method);
+    // 自定义配置...
+    return request;
+};
+
+IDownloadBackend backend = new UnityWebRequestBackend(creator);
+```
+
+### UnityWebRequestDownloaderBase
+
+抽象基类，封装所有下载器的通用逻辑。
+
+**职责：**
+- 管理请求生命周期和状态转换
+- 实现看门狗监控机制
+- 追踪下载进度和字节数
+- 处理超时和错误
+
+**生命周期：**
+
+```
+None ──► SendRequest() ──► Running ──► PollingRequest() ──┬──► Succeed
+                                                          ├──► Failed
+                                                          └──► Aborted
+```
+
+### 具体下载器
+
+| 下载器 | 实现接口 | 使用场景 |
+|--------|----------|----------|
+| `UnityWebRequestFileDownloader` | `IDownloadFileRequest` | 大文件下载到本地 |
+| `UnityWebRequestHeadDownloader` | `IDownloadHeadRequest` | 检查资源信息 |
+| `UnityWebRequestBytesDownloader` | `IDownloadBytesRequest` | 小文件内存加载 |
+| `UnityWebRequestTextDownloader` | `IDownloadTextRequest` | 文本文件下载 |
+| `UnityWebRequestAssetBundleDownloader` | `IDownloadAssetBundleRequest` | AB 包下载加载 |
+| `VirtualFileDownloader` | `IDownloadFileRequest` | 编辑器模拟下载 |
+
+---
+
+## 使用示例
+
+### 基础文件下载
+
+```csharp
+// 1. 创建后端和请求
+IDownloadBackend backend = new UnityWebRequestBackend();
+var args = new DownloadFileRequestArgs(
+    url: "https://example.com/file.zip",
+    savePath: "/path/to/save/file.zip",
+    timeout: 30,
+    watchdogTime: 0);
+IDownloadFileRequest request = backend.CreateFileRequest(args);
+
+// 2. 发起并轮询
+request.SendRequest();
+while (!request.IsDone)
+{
+    await Task.Yield();
+    // 可选：显示进度
+    float progress = request.DownloadProgress;
+}
+
+// 3. 检查结果
+if (request.Status == EDownloadRequestStatus.Succeed)
+{
+    Debug.Log("下载成功");
+}
+else
+{
+    Debug.LogError($"下载失败: {request.Error}");
+}
+
+// 4. 清理资源
+request.Dispose();
+```
+
+### 断点续传
+
+```csharp
+// 获取已下载的文件大小
+long existingFileSize = new FileInfo(savePath).Length;
+
+var args = new DownloadFileRequestArgs(
+    url: url,
+    savePath: savePath,
+    timeout: 30,
+    watchdogTime: 0,
+    appendToFile: true,                 // 追加写入
+    removeFileOnAbort: false,           // 中止时保留文件
+    resumeFromBytes: existingFileSize); // 断点位置
+
+IDownloadFileRequest request = backend.CreateFileRequest(args);
+request.SendRequest();
+// ... 轮询等待完成
+```
+
+### 看门狗保护
+
+```csharp
+var args = new DownloadFileRequestArgs(
+    url: url,
+    savePath: path,
+    timeout: 30,
+    watchdogTime: 30); // 30秒无数据自动中止
+
+IDownloadFileRequest request = backend.CreateFileRequest(args);
+request.SendRequest();
+
+while (!request.IsDone)
+{
+    await Task.Yield();
+}
+
+// 检查是否因看门狗超时而中止
+if (request.Status == EDownloadRequestStatus.Aborted)
+{
+    Debug.LogWarning("下载超时，已自动中止");
+}
+```
+
+### HEAD 请求获取文件信息
+
+```csharp
+var args = new DownloadDataRequestArgs(
+    url: "https://example.com/file.zip",
+    timeout: 30,
+    watchdogTime: 0);
+
+IDownloadHeadRequest request = backend.CreateHeadRequest(args);
+request.SendRequest();
+
+while (!request.IsDone)
+{
+    await Task.Yield();
+}
+
+if (request.Status == EDownloadRequestStatus.Succeed)
+{
+    long fileSize = request.ContentLength;
+    string etag = request.ETag;
+    string lastModified = request.LastModified;
+
+    Debug.Log($"文件大小: {fileSize}, ETag: {etag}");
+}
+```
+
+### 下载字节数据
+
+```csharp
+var args = new DownloadDataRequestArgs(
+    url: "https://example.com/data.json",
+    timeout: 30,
+    watchdogTime: 0);
+
+IDownloadBytesRequest request = backend.CreateBytesRequest(args);
+request.SendRequest();
+
+while (!request.IsDone)
+{
+    await Task.Yield();
+}
+
+if (request.Status == EDownloadRequestStatus.Succeed)
+{
+    byte[] data = request.Result;
+    // 处理数据...
+}
+```
+
+---
+
+## 设计模式
+
+### 工厂模式
+
+`IDownloadBackend` 作为工厂接口，创建各类下载请求对象：
+
+```
+IDownloadBackend
+    ├── CreateHeadRequest()    ──► IDownloadHeadRequest
+    ├── CreateFileRequest()    ──► IDownloadFileRequest
+    ├── CreateBytesRequest()   ──► IDownloadBytesRequest
+    ├── CreateTextRequest()    ──► IDownloadTextRequest
+    ├── CreateAssetBundleRequest() ──► IDownloadAssetBundleRequest
+    └── CreateSimulateRequest() ──► IDownloadFileRequest
+```
+
+### 策略模式
+
+通过实现 `IDownloadBackend` 接口，可以替换底层网络库：
+
+```
+IDownloadBackend (接口)
+    ├── UnityWebRequestBackend  (默认实现)
+    ├── BestHTTPBackend         (可扩展)
+    └── CustomBackend           (自定义)
+```
+
+### 状态机模式
+
+请求生命周期通过状态机管理：
+
+```
+┌──────┐    SendRequest()    ┌─────────┐
+│ None │ ──────────────────► │ Running │
+└──────┘                     └────┬────┘
+                                  │ PollingRequest()
+                    ┌─────────────┼─────────────┐
+                    ▼             ▼             ▼
+              ┌─────────┐  ┌──────────┐  ┌─────────┐
+              │ Succeed │  │  Failed  │  │ Aborted │
+              └─────────┘  └──────────┘  └─────────┘
+```
+
+### 看门狗模式
+
+监控数据接收，防止网络卡顿导致请求无限等待：
+
+```
+每帧轮询 PollingRequest()
+    │
+    ├── 收到新数据 ──► 重置计时器
+    │
+    └── 未收到数据 ──► 计时器累加
+                           │
+                           └── 超过 WatchdogTime ──► AbortRequest()
+```
+
+---
+
+## 类继承关系
+
+```
+IDownloadRequest (基础接口)
+    │
+    ├── IDownloadHeadRequest        (HEAD 请求)
+    ├── IDownloadFileRequest        (文件下载)
+    ├── IDownloadBytesRequest       (字节下载)
+    ├── IDownloadTextRequest        (文本下载)
+    └── IDownloadAssetBundleRequest (AssetBundle 下载)
+
+UnityWebRequestDownloaderBase (抽象基类)
+    │
+    ├── UnityWebRequestFileDownloader      ──► IDownloadFileRequest
+    ├── UnityWebRequestHeadDownloader      ──► IDownloadHeadRequest
+    ├── UnityWebRequestBytesDownloader     ──► IDownloadBytesRequest
+    ├── UnityWebRequestTextDownloader      ──► IDownloadTextRequest
+    └── UnityWebRequestAssetBundleDownloader ──► IDownloadAssetBundleRequest
+
+VirtualFileDownloader (独立实现) ──► IDownloadFileRequest
+```
+
+---
+
+## 工具类
+
+### DownloadSystemHelper
+
+提供跨平台的工具函数：
+
+| 方法 | 说明 |
+|------|------|
+| `ConvertToWWWPath()` | 转换本地路径为 WWW 协议 URL |
+| `IsRequestLocalFile()` | 判断是否本地文件请求 |
+
+### WebRequestCounter
+
+请求失败计数器，用于诊断统计：
+
+- 线程安全：内部使用 `Dictionary` 且未加锁，约定只在主线程调用；如需多线程统计请在外层加锁或改造实现
+- Key 规则：`$"{packageName}_{eventName}"`
+- 统计口径：**仅统计网络请求失败**（`IDownloadRequest.Status != Succeed` 时记录），不统计内容为空、校验失败、解析失败等业务层失败
+
+```csharp
+// 记录失败
+WebRequestCounter.RecordRequestFailed(packageName, eventName);
+
+// 查询失败次数
+int count = WebRequestCounter.GetRequestFailedCount(packageName, eventName);
+```
+
+---
+
+## 注意事项
+
+1. **资源释放**：使用完毕后务必调用 `Dispose()` 释放资源
+   - `AbortRequest()` 仅用于中止请求与切换状态，不等同于释放资源；无论成功/失败/中止都需要 `Dispose()`
+   - 推荐使用 `try/finally` 确保释放（尤其是上层可能提前中止的场景）
+2. **断点续传**：需要服务器支持 `Range` 请求头和 `206 Partial Content` 响应
+   - 若服务端不支持 Range 仍返回 200，全量内容可能会被追加写入，导致文件损坏
+3. **看门狗超时**：设置为 0 表示禁用，建议根据网络环境设置合理值
+4. **内存下载**：`IDownloadBytesRequest` 会将整个响应体加载到内存，不适合大文件
+5. **驱动更新**：部分第三方网络库实现的 backend 可能需要每帧调用 `IDownloadBackend.Update()` 进行驱动
+6. **中止语义**：`Aborted` 可能来自用户主动 `AbortRequest()` 或看门狗超时；中止场景下 `HttpCode/Error` 可能为默认值（例如 0/空）
+7. **线程安全**：所有下载请求的创建和轮询应在主线程进行

Assets/YooAsset/Runtime/DownloadSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 2c65d3ba8da65004b8d36dbeecc6c6be
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/DownloadSystem/WebRequestCounter.cs

@@ -1,9 +1,14 @@
-using System;
-using System.Collections;
 using System.Collections.Generic;
 
 namespace YooAsset
 {
+    /// <summary>
+    /// 网络请求失败计数器（诊断用）
+    /// </summary>
+    /// <remarks>
+    /// 线程安全：内部使用 Dictionary 且未加锁，约定只在 Unity 主线程调用。
+    /// 如需在多线程/回调线程调用，请在外层加锁或改为并发容器实现。
+    /// </remarks>
     internal class WebRequestCounter
     {
 #if UNITY_EDITOR
@@ -15,12 +20,12 @@ namespace YooAsset
 #endif
 
         /// <summary>
-        /// 记录网络请求失败事件的次数
+        /// 失败计数记录表（key = $"{packageName}_{eventName}"）
         /// </summary>
         private static readonly Dictionary<string, int> _requestFailedRecorder = new Dictionary<string, int>(1000);
 
         /// <summary>
-        /// 记录请求失败事件
+        /// 记录一次失败
         /// </summary>
         public static void RecordRequestFailed(string packageName, string eventName)
         {
@@ -31,14 +36,14 @@ namespace YooAsset
         }
 
         /// <summary>
-        /// 获取请求失败的次数
+        /// 获取失败次数
         /// </summary>
         public static int GetRequestFailedCount(string packageName, string eventName)
         {
             string key = $"{packageName}_{eventName}";
-            if (_requestFailedRecorder.ContainsKey(key) == false)
+            if (_requestFailedRecorder.TryGetValue(key, out int count))
-                _requestFailedRecorder.Add(key, 0);
+                return count;
-            return _requestFailedRecorder[key];
+            return 0;
         }
     }
 }

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/CatalogTools.cs

@@ -205,6 +205,9 @@ namespace YooAsset
         /// </summary>
         public static DefaultBuildinFileCatalog DeserializeFromBinary(byte[] binaryData)
         {
+            if (binaryData == null || binaryData.Length == 0)
+                throw new Exception("Catalog file data is null or empty !");
+
             // 创建缓存器
             BufferReader buffer = new BufferReader(binaryData);
 

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/DefaultBuildinFileSystem.cs

@@ -25,6 +25,11 @@ namespace YooAsset
         protected IFileSystem _unpackFileSystem;
         protected string _packageRoot;
 
+        /// <summary>
+        /// 下载后台接口
+        /// </summary>
+        public IDownloadBackend DownloadBackend { private set; get; }
+
         /// <summary>
         /// 包裹名称
         /// </summary>
@@ -53,6 +58,11 @@ namespace YooAsset
         }
 
         #region 自定义参数
+        /// <summary>
+        /// 自定义参数：UnityWebRequest 创建委托
+        /// </summary>
+        public UnityWebRequestCreator WebRequestCreator { private set; get; }
+
         /// <summary>
         /// 自定义参数：覆盖安装缓存清理模式
         /// </summary>
@@ -66,7 +76,7 @@ namespace YooAsset
         /// <summary>
         /// 自定义参数：初始化的时候缓存文件校验最大并发数
         /// </summary>
-        public int FileVerifyMaxConcurrency { private set; get; } = int.MaxValue;
+        public int FileVerifyMaxConcurrency { private set; get; } = 32;
 
         /// <summary>
         /// 自定义参数：数据文件追加文件格式
@@ -156,6 +166,13 @@ namespace YooAsset
                 var operation = new DBFSLoadRawBundleOperation(this, bundle);
                 return operation;
             }
+#if TUANJIE_1_7_OR_NEWER
+            else if (bundle.BundleType == (int)EBuildBundleType.InstantBundle)
+            {
+                var operation = new DBFSLoadInstantBundleOperation(this, bundle);
+                return operation;
+            }
+#endif
             else
             {
                 string error = $"{nameof(DefaultBuildinFileSystem)} not support load bundle type : {bundle.BundleType}";
@@ -166,7 +183,15 @@ namespace YooAsset
 
         public virtual void SetParameter(string name, object value)
         {
-            if (name == FileSystemParametersDefine.INSTALL_CLEAR_MODE)
+            if (name == FileSystemParametersDefine.DOWNLOAD_BACKEND)
+            {
+                DownloadBackend = (IDownloadBackend)value;
+            }
+            else if (name == FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR)
+            {
+                WebRequestCreator = (UnityWebRequestCreator)value;
+            }
+            else if (name == FileSystemParametersDefine.INSTALL_CLEAR_MODE)
             {
                 InstallClearMode = (EOverwriteInstallClearMode)value;
             }
@@ -225,10 +250,16 @@ namespace YooAsset
             else
                 _packageRoot = packageRoot;
 
+            // 创建默认的下载后台接口
+            if (DownloadBackend == null)
+                DownloadBackend = new UnityWebRequestBackend(WebRequestCreator);
+
             // 创建解压文件系统
             var remoteServices = new DefaultUnpackRemoteServices(_packageRoot);
             _unpackFileSystem = new DefaultUnpackFileSystem();
             _unpackFileSystem.SetParameter(FileSystemParametersDefine.REMOTE_SERVICES, remoteServices);
+            _unpackFileSystem.SetParameter(FileSystemParametersDefine.DOWNLOAD_BACKEND, DownloadBackend);
+            _unpackFileSystem.SetParameter(FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR, WebRequestCreator);
             _unpackFileSystem.SetParameter(FileSystemParametersDefine.INSTALL_CLEAR_MODE, InstallClearMode);
             _unpackFileSystem.SetParameter(FileSystemParametersDefine.FILE_VERIFY_LEVEL, FileVerifyLevel);
             _unpackFileSystem.SetParameter(FileSystemParametersDefine.FILE_VERIFY_MAX_CONCURRENCY, FileVerifyMaxConcurrency);
@@ -239,6 +270,17 @@ namespace YooAsset
         }
         public virtual void OnDestroy()
         {
+            if (_unpackFileSystem != null)
+            {
+                _unpackFileSystem.OnDestroy();
+                _unpackFileSystem = null;
+            }
+
+            if (DownloadBackend != null)
+            {
+                DownloadBackend.Dispose();
+                DownloadBackend = null;
+            }
         }
 
         public virtual bool Belong(PackageBundle bundle)

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/DBFSInitializeOperation.cs

@@ -78,7 +78,7 @@ namespace YooAsset
                     string packageVersion = _requestBuildinPackageVersionOp.PackageVersion;
                     string destFilePath = GetCopyPackageHashDestPath(packageVersion);
                     string sourceFilePath = _fileSystem.GetBuildinPackageHashFilePath(packageVersion);
-                    _copyBuildinHashFileOp = new CopyBuildinFileOperation(sourceFilePath, destFilePath);
+                    _copyBuildinHashFileOp = new CopyBuildinFileOperation(_fileSystem, sourceFilePath, destFilePath);
                     _copyBuildinHashFileOp.StartOperation();
                     AddChildOperation(_copyBuildinHashFileOp);
                 }
@@ -106,7 +106,7 @@ namespace YooAsset
                     string packageVersion = _requestBuildinPackageVersionOp.PackageVersion;
                     string destFilePath = GetCopyPackageManifestDestPath(packageVersion);
                     string sourceFilePath = _fileSystem.GetBuildinPackageManifestFilePath(packageVersion);
-                    _copyBuildinManifestFileOp = new CopyBuildinFileOperation(sourceFilePath, destFilePath);
+                    _copyBuildinManifestFileOp = new CopyBuildinFileOperation(_fileSystem, sourceFilePath, destFilePath);
                     _copyBuildinManifestFileOp.StartOperation();
                     AddChildOperation(_copyBuildinManifestFileOp);
                 }

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/internal/CopyBuildinFileOperation.cs

@@ -14,13 +14,15 @@ namespace YooAsset
             Done,
         }
 
-        private UnityWebFileRequestOperation _webFileRequestOp;
+        private readonly DefaultBuildinFileSystem _fileSystem;
         private readonly string _sourceFilePath;
         private readonly string _destFilePath;
+        private IDownloadFileRequest _webFileRequestOp;
         private ESteps _steps = ESteps.None;
 
-        public CopyBuildinFileOperation(string sourceFilePath, string destFilePath)
+        public CopyBuildinFileOperation(DefaultBuildinFileSystem fileSystem, string sourceFilePath, string destFilePath)
         {
+            _fileSystem = fileSystem;
             _sourceFilePath = sourceFilePath;
             _destFilePath = destFilePath;
         }
@@ -76,16 +78,15 @@ namespace YooAsset
                 if (_webFileRequestOp == null)
                 {
                     string url = DownloadSystemHelper.ConvertToWWWPath(_sourceFilePath);
-                    _webFileRequestOp = new UnityWebFileRequestOperation(url, _destFilePath, 60);
+                    var args = new DownloadFileRequestArgs(url, _destFilePath, 60, 0);
-                    _webFileRequestOp.StartOperation();
+                    _webFileRequestOp = _fileSystem.DownloadBackend.CreateFileRequest(args);
-                    AddChildOperation(_webFileRequestOp);
+                    _webFileRequestOp.SendRequest();
                 }
 
-                _webFileRequestOp.UpdateOperation();
                 if (_webFileRequestOp.IsDone == false)
                     return;
 
-                if (_webFileRequestOp.Status == EOperationStatus.Succeed)
+                if (_webFileRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/internal/LoadBuildinCatalogFileOperation.cs

@@ -15,7 +15,7 @@ namespace YooAsset
         }
 
         private readonly DefaultBuildinFileSystem _fileSystem;
-        private UnityWebDataRequestOperation _webDataRequestOp;
+        private IDownloadBytesRequest _webDataRequestOp;
         private byte[] _fileData;
         private ESteps _steps = ESteps.None;
 
@@ -57,16 +57,15 @@ namespace YooAsset
                 {
                     string filePath = _fileSystem.GetCatalogBinaryFileLoadPath();
                     string url = DownloadSystemHelper.ConvertToWWWPath(filePath);
-                    _webDataRequestOp = new UnityWebDataRequestOperation(url, 60);
+                    var args = new DownloadDataRequestArgs(url, 60, 0);
-                    _webDataRequestOp.StartOperation();
+                    _webDataRequestOp = _fileSystem.DownloadBackend.CreateBytesRequest(args);
-                    AddChildOperation(_webDataRequestOp);
+                    _webDataRequestOp.SendRequest();
                 }
 
-                _webDataRequestOp.UpdateOperation();
                 if (_webDataRequestOp.IsDone == false)
                     return;
 
-                if (_webDataRequestOp.Status == EOperationStatus.Succeed)
+                if (_webDataRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _fileData = _webDataRequestOp.Result;
                     _steps = ESteps.LoadCatalog;
@@ -87,11 +86,11 @@ namespace YooAsset
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;
                 }
-                catch (Exception e)
+                catch (Exception ex)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Failed;
-                    Error = $"Failed to load catalog file : {e.Message}";
+                    Error = $"Failed to load catalog file : {ex.Message}";
                 }
             }
         }

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/internal/LoadBuildinPackageManifestOperation.cs

@@ -17,7 +17,7 @@ namespace YooAsset
         private readonly DefaultBuildinFileSystem _fileSystem;
         private readonly string _packageVersion;
         private readonly string _packageHash;
-        private UnityWebDataRequestOperation _webDataRequestOp;
+        private IDownloadBytesRequest _webDataRequestOp;
         private DeserializeManifestOperation _deserializer;
         private byte[] _fileData;
         private ESteps _steps = ESteps.None;
@@ -63,16 +63,15 @@ namespace YooAsset
                 {
                     string filePath = _fileSystem.GetBuildinPackageManifestFilePath(_packageVersion);
                     string url = DownloadSystemHelper.ConvertToWWWPath(filePath);
-                    _webDataRequestOp = new UnityWebDataRequestOperation(url, 60);
+                    var args = new DownloadDataRequestArgs(url, 60, 0);
-                    _webDataRequestOp.StartOperation();
+                    _webDataRequestOp = _fileSystem.DownloadBackend.CreateBytesRequest(args);
-                    AddChildOperation(_webDataRequestOp);
+                    _webDataRequestOp.SendRequest();
                 }
 
-                _webDataRequestOp.UpdateOperation();
                 if (_webDataRequestOp.IsDone == false)
                     return;
 
-                if (_webDataRequestOp.Status == EOperationStatus.Succeed)
+                if (_webDataRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _fileData = _webDataRequestOp.Result;
                     _steps = ESteps.VerifyFileData;

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/internal/RequestBuildinPackageHashOperation.cs

@@ -15,7 +15,7 @@ namespace YooAsset
 
         private readonly DefaultBuildinFileSystem _fileSystem;
         private readonly string _packageVersion;
-        private UnityWebTextRequestOperation _webTextRequestOp;
+        private IDownloadTextRequest _webTextRequestOp;
         private ESteps _steps = ESteps.None;
 
         /// <summary>
@@ -58,16 +58,15 @@ namespace YooAsset
                 {
                     string filePath = _fileSystem.GetBuildinPackageHashFilePath(_packageVersion);
                     string url = DownloadSystemHelper.ConvertToWWWPath(filePath);
-                    _webTextRequestOp = new UnityWebTextRequestOperation(url, 60);
+                    var args = new DownloadDataRequestArgs(url, 60, 0);
-                    _webTextRequestOp.StartOperation();
+                    _webTextRequestOp = _fileSystem.DownloadBackend.CreateTextRequest(args);
-                    AddChildOperation(_webTextRequestOp);
+                    _webTextRequestOp.SendRequest();
                 }
 
-                _webTextRequestOp.UpdateOperation();
                 if (_webTextRequestOp.IsDone == false)
                     return;
 
-                if (_webTextRequestOp.Status == EOperationStatus.Succeed)
+                if (_webTextRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     PackageHash = _webTextRequestOp.Result;
                     _steps = ESteps.CheckResult;

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/Operation/internal/RequestBuildinPackageVersionOperation.cs

@@ -14,7 +14,7 @@ namespace YooAsset
         }
 
         private readonly DefaultBuildinFileSystem _fileSystem;
-        private UnityWebTextRequestOperation _webTextRequestOp;
+        private IDownloadTextRequest _webTextRequestOp;
         private ESteps _steps = ESteps.None;
 
         /// <summary>
@@ -56,16 +56,15 @@ namespace YooAsset
                 {
                     string filePath = _fileSystem.GetBuildinPackageVersionFilePath();
                     string url = DownloadSystemHelper.ConvertToWWWPath(filePath);
-                    _webTextRequestOp = new UnityWebTextRequestOperation(url, 60);
+                    var args = new DownloadDataRequestArgs(url, 60, 0);
-                    _webTextRequestOp.StartOperation();
+                    _webTextRequestOp = _fileSystem.DownloadBackend.CreateTextRequest(args);
-                    AddChildOperation(_webTextRequestOp);
+                    _webTextRequestOp.SendRequest();
                 }
 
-                _webTextRequestOp.UpdateOperation();
                 if (_webTextRequestOp.IsDone == false)
                     return;
 
-                if (_webTextRequestOp.Status == EOperationStatus.Succeed)
+                if (_webTextRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     PackageVersion = _webTextRequestOp.Result;
                     _steps = ESteps.CheckResult;

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/README.md

@@ -0,0 +1,488 @@
+# DefaultBuildinFileSystem 内置文件系统
+
+## 模块概述
+
+DefaultBuildinFileSystem 是 YooAsset 的**内置资源文件系统**，用于管理打包到应用程序中的资源文件（StreamingAssets）。该文件系统支持 AssetBundle 和原生文件的加载，并内置解压文件系统以处理 Android/OpenHarmony 平台的特殊需求。
+
+### 核心特性
+
+- **内置资源管理**：管理 StreamingAssets 目录下的资源文件
+- **Catalog 目录系统**：使用目录文件快速查询内置资源
+- **自动解压机制**：Android/OpenHarmony 平台自动解压加密和原生文件
+- **清单拷贝功能**：支持将内置清单拷贝到沙盒目录
+- **加密资源支持**：通过解密服务接口支持加密资源加载
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **跨平台支持** | 统一处理各平台 StreamingAssets 的访问差异 |
+| **高效查询** | 通过 Catalog 文件快速判断资源是否内置 |
+| **自动解压** | 自动处理 Android 平台无法直接访问的资源 |
+| **灵活配置** | 支持多种参数配置适应不同需求 |
+
+---
+
+## 文件结构
+
+```
+DefaultBuildinFileSystem/
+├── DefaultBuildinFileSystem.cs           # 文件系统主类
+├── DefaultBuildinFileSystemDefine.cs     # 常量定义
+├── DefaultBuildinFileCatalog.cs          # 内置资源目录结构
+├── CatalogDefine.cs                      # Catalog 文件格式定义
+├── CatalogTools.cs                       # Catalog 序列化工具
+└── Operation/                            # 操作类
+    ├── DBFSInitializeOperation.cs        # 初始化操作
+    ├── DBFSRequestPackageVersionOperation.cs   # 请求版本操作
+    ├── DBFSLoadPackageManifestOperation.cs     # 加载清单操作
+    ├── DBFSLoadBundleOperation.cs        # 加载资源包操作
+    └── internal/                         # 内部操作类
+        ├── CopyBuildinFileOperation.cs           # 拷贝内置文件操作
+        ├── LoadBuildinCatalogFileOperation.cs    # 加载 Catalog 文件操作
+        ├── LoadBuildinPackageManifestOperation.cs# 加载清单文件操作
+        ├── RequestBuildinPackageHashOperation.cs # 请求哈希文件操作
+        └── RequestBuildinPackageVersionOperation.cs # 请求版本文件操作
+```
+
+---
+
+## 核心类说明
+
+### DefaultBuildinFileSystem
+
+内置文件系统的主类，实现 `IFileSystem` 接口。
+
+#### 基本属性
+
+| 属性 | 类型 | 说明 |
+|------|------|------|
+| `PackageName` | `string` | 包裹名称 |
+| `FileRoot` | `string` | 文件根目录（StreamingAssets 下的包裹目录） |
+| `FileCount` | `int` | 已记录的内置文件数量 |
+| `DownloadBackend` | `IDownloadBackend` | 下载后台接口 |
+
+#### 自定义参数
+
+| 参数 | 类型 | 默认值 | 说明 |
+|------|------|--------|------|
+| `InstallClearMode` | `EOverwriteInstallClearMode` | `ClearAllManifestFiles` | 覆盖安装时的缓存清理模式 |
+| `FileVerifyLevel` | `EFileVerifyLevel` | `Middle` | 文件校验级别 |
+| `FileVerifyMaxConcurrency` | `int` | `32` | 文件校验最大并发数 |
+| `AppendFileExtension` | `bool` | `false` | 是否追加文件扩展名 |
+| `DisableCatalogFile` | `bool` | `false` | 禁用 Catalog 目录文件 |
+| `CopyBuildinPackageManifest` | `bool` | `false` | 是否拷贝内置清单到沙盒 |
+| `CopyBuildinPackageManifestDestRoot` | `string` | `null` | 清单拷贝目标目录 |
+| `UnpackFileSystemRoot` | `string` | `null` | 解压文件系统根目录 |
+| `DecryptionServices` | `IDecryptionServices` | `null` | 解密服务接口 |
+| `ManifestServices` | `IManifestRestoreServices` | `null` | 清单恢复服务接口 |
+| `CopyLocalFileServices` | `ICopyLocalFileServices` | `null` | 本地文件拷贝服务接口 |
+
+#### 核心方法
+
+```csharp
+// 生命周期
+void OnCreate(string packageName, string packageRoot);
+void OnDestroy();
+void SetParameter(string name, object value);
+
+// 异步操作
+FSInitializeFileSystemOperation InitializeFileSystemAsync();
+FSRequestPackageVersionOperation RequestPackageVersionAsync(bool appendTimeTicks, int timeout);
+FSLoadPackageManifestOperation LoadPackageManifestAsync(string packageVersion, int timeout);
+FSLoadBundleOperation LoadBundleFile(PackageBundle bundle);
+FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options);
+FSClearCacheFilesOperation ClearCacheFilesAsync(PackageManifest manifest, ClearCacheFilesOptions options);
+
+// 文件查询
+bool Belong(PackageBundle bundle);      // 检查是否属于内置文件
+bool Exists(PackageBundle bundle);      // 检查文件是否存在
+bool NeedDownload(PackageBundle bundle);// 始终返回 false
+bool NeedUnpack(PackageBundle bundle);  // 检查是否需要解压
+bool NeedImport(PackageBundle bundle);  // 始终返回 false
+
+// 文件访问
+string GetBundleFilePath(PackageBundle bundle);
+byte[] ReadBundleFileData(PackageBundle bundle);
+string ReadBundleFileText(PackageBundle bundle);
+```
+
+---
+
+## Catalog 目录系统
+
+### DefaultBuildinFileCatalog
+
+内置资源目录结构，记录所有内置资源文件的信息。
+
+```csharp
+[Serializable]
+internal class DefaultBuildinFileCatalog
+{
+    [Serializable]
+    public class FileWrapper
+    {
+        public string BundleGUID;   // 资源包 GUID
+        public string FileName;     // 文件名
+    }
+
+    public string FileVersion;      // 文件版本
+    public string PackageName;      // 包裹名称
+    public string PackageVersion;   // 包裹版本
+    public List<FileWrapper> Wrappers;  // 文件列表
+}
+```
+
+### CatalogDefine
+
+Catalog 文件格式常量定义。
+
+```csharp
+internal class CatalogDefine
+{
+    public const int FileMaxSize = 104857600;   // 文件极限大小（100MB）
+    public const uint FileSign = 0x133C5EE;     // 文件头标记
+    public const string FileVersion = "1.0.0";  // 文件格式版本
+}
+```
+
+### CatalogTools
+
+Catalog 文件的序列化和反序列化工具。
+
+| 方法 | 说明 |
+|------|------|
+| `CreateCatalogFile()` | 生成包裹的内置资源目录文件（编辑器） |
+| `CreateEmptyCatalogFile()` | 生成空的内置资源目录文件（编辑器） |
+| `SerializeToJson()` | 序列化为 JSON 文件 |
+| `DeserializeFromJson()` | 从 JSON 文件反序列化 |
+| `SerializeToBinary()` | 序列化为二进制文件 |
+| `DeserializeFromBinary()` | 从二进制文件反序列化 |
+
+---
+
+## 操作类说明
+
+### DBFSInitializeOperation
+
+初始化操作，执行以下步骤：
+
+```
+状态流程：
+┌─────────────────────────────────────────────────────────────┐
+│  CopyBuildinPackageManifest = true ?                        │
+│      │                                                      │
+│      ├── Yes ──► LoadBuildinPackageVersion                  │
+│      │               └── RequestBuildinPackageVersionOp     │
+│      │                       ↓                              │
+│      │           CopyBuildinPackageHash                     │
+│      │               └── CopyBuildinFileOperation           │
+│      │                       ↓                              │
+│      │           CopyBuildinPackageManifest                 │
+│      │               └── CopyBuildinFileOperation           │
+│      │                       ↓                              │
+│      └── No ─────────────────┘                              │
+│                              ↓                              │
+│                  InitUnpackFileSystem                       │
+│                      └── DefaultUnpackFileSystem.Init       │
+│                              ↓                              │
+│                  DisableCatalogFile = true ?                │
+│                      ├── Yes ──► Done (Succeed)             │
+│                      └── No ──► LoadCatalogFile             │
+│                                     └── LoadBuildinCatalog  │
+│                                             ↓               │
+│                                     RecordCatalogFile       │
+│                                             ↓               │
+│                                     Done (Succeed)          │
+└─────────────────────────────────────────────────────────────┘
+```
+
+### DBFSLoadBundleOperation
+
+加载资源包操作，支持多种资源类型。
+
+#### DBFSLoadAssetBundleOperation
+
+加载 AssetBundle 文件。
+
+```
+状态流程：
+LoadAssetBundle
+    ├── 加密资源 ──► DecryptionServices.LoadAssetBundle[Async]
+    └── 普通资源 ──► AssetBundle.LoadFromFile[Async]
+            ↓
+CheckResult
+    ├── 成功 ──► AssetBundleResult
+    └── 失败 ──► Error
+```
+
+#### DBFSLoadRawBundleOperation
+
+加载原生文件。
+
+```
+状态流程：
+LoadBuildinRawBundle
+    ├── Android 平台 ──► Error（不支持直接读取）
+    └── 其他平台 ──► RawBundleResult
+```
+
+#### DBFSLoadInstantBundleOperation
+
+加载团结引擎（Tuanjie）专用资源包（需要 `TUANJIE_1_7_OR_NEWER` 宏）。
+
+---
+
+## 内部操作类
+
+### LoadBuildinCatalogFileOperation
+
+加载 Catalog 目录文件。
+
+```
+状态流程：
+TryLoadFileData
+    ├── 文件存在 ──► File.ReadAllBytes
+    └── 文件不存在 ──► RequestFileData (UnityWebRequest)
+            ↓
+LoadCatalog
+    └── CatalogTools.DeserializeFromBinary
+```
+
+### CopyBuildinFileOperation
+
+拷贝内置文件到目标路径。
+
+```
+状态流程：
+CheckFileExist
+    ├── 目标已存在 ──► Done (Succeed)
+    └── 目标不存在 ──► TryCopyFile
+            ↓
+TryCopyFile
+    ├── 源文件存在 ──► File.Copy
+    └── 源文件不存在 ──► UnpackFile (UnityWebRequest)
+```
+
+---
+
+## 解压机制
+
+### 自动解压条件
+
+在 Android/OpenHarmony 平台上，以下情况需要解压到沙盒：
+
+```csharp
+protected virtual bool IsUnpackBundleFile(PackageBundle bundle)
+{
+#if UNITY_ANDROID || UNITY_OPENHARMONY
+    if (bundle.Encrypted)       // 加密资源
+        return true;
+    if (bundle.BundleType == RawBundle)  // 原生文件
+        return true;
+    return false;
+#else
+    return false;
+#endif
+}
+```
+
+### 解压文件系统
+
+内置文件系统在创建时会自动创建一个 `DefaultUnpackFileSystem` 实例：
+
+```csharp
+public virtual void OnCreate(string packageName, string packageRoot)
+{
+    // 创建解压文件系统
+    var remoteServices = new DefaultUnpackRemoteServices(_packageRoot);
+    _unpackFileSystem = new DefaultUnpackFileSystem();
+    _unpackFileSystem.SetParameter(REMOTE_SERVICES, remoteServices);
+    _unpackFileSystem.SetParameter(FILE_VERIFY_LEVEL, FileVerifyLevel);
+    // ... 其他参数
+    _unpackFileSystem.OnCreate(packageName, UnpackFileSystemRoot);
+}
+```
+
+---
+
+## 平台差异处理
+
+### Android 平台限制
+
+```
+┌─────────────────────────────────────────────────────────────┐
+│                     Android 平台特殊处理                     │
+├─────────────────────────────────────────────────────────────┤
+│  StreamingAssets 文件位于 APK 压缩包内，无法直接访问：        │
+│                                                             │
+│  ✓ AssetBundle.LoadFromFile    支持（Unity 内部处理）        │
+│  ✗ File.ReadAllBytes           不支持                       │
+│  ✗ File.Exists                 不支持                       │
+│  ✓ UnityWebRequest             支持（jar:file:// 协议）      │
+│                                                             │
+│  解决方案：                                                  │
+│  1. 加密资源 → 自动解压到沙盒                                │
+│  2. 原生文件 → 自动解压到沙盒                                │
+│  3. Catalog  → 使用 UnityWebRequest 读取                    │
+└─────────────────────────────────────────────────────────────┘
+```
+
+### WebGL 平台
+
+```csharp
+#if UNITY_WEBGL
+    _steps = ESteps.Done;
+    Status = EOperationStatus.Failed;
+    Error = $"{nameof(DefaultBuildinFileSystem)} is not support WEBGL platform !";
+#endif
+```
+
+WebGL 平台不支持 DefaultBuildinFileSystem，应使用 `DefaultWebServerFileSystem`。
+
+---
+
+## 使用示例
+
+### 基础配置
+
+```csharp
+// 创建内置文件系统参数
+var buildinParams = FileSystemParameters.CreateDefaultBuildinFileSystemParameters();
+
+// 初始化包裹
+var initParams = new OfflinePlayModeParameters();
+initParams.BuildinFileSystemParameters = buildinParams;
+var initOp = package.InitializeAsync(initParams);
+```
+
+### 配置解密服务
+
+```csharp
+var buildinParams = FileSystemParameters.CreateDefaultBuildinFileSystemParameters();
+
+// 设置解密服务
+buildinParams.AddParameter(
+    FileSystemParametersDefine.DECRYPTION_SERVICES,
+    new MyDecryptionServices()
+);
+```
+
+### 配置清单拷贝
+
+```csharp
+var buildinParams = FileSystemParameters.CreateDefaultBuildinFileSystemParameters();
+
+// 启用清单拷贝（用于离线模式切换到联机模式）
+buildinParams.AddParameter(
+    FileSystemParametersDefine.COPY_BUILDIN_PACKAGE_MANIFEST,
+    true
+);
+
+// 可选：指定拷贝目标目录
+buildinParams.AddParameter(
+    FileSystemParametersDefine.COPY_BUILDIN_PACKAGE_MANIFEST_DEST_ROOT,
+    "/custom/path"
+);
+```
+
+### 禁用 Catalog 文件
+
+```csharp
+var buildinParams = FileSystemParameters.CreateDefaultBuildinFileSystemParameters();
+
+// 禁用 Catalog（所有资源视为内置）
+buildinParams.AddParameter(
+    FileSystemParametersDefine.DISABLE_CATALOG_FILE,
+    true
+);
+```
+
+### 配置解压文件系统根目录
+
+```csharp
+var buildinParams = FileSystemParameters.CreateDefaultBuildinFileSystemParameters();
+
+// 设置解压文件系统的根目录
+buildinParams.AddParameter(
+    FileSystemParametersDefine.UNPACK_FILE_SYSTEM_ROOT,
+    "/custom/unpack/path"
+);
+```
+
+---
+
+## 参数常量
+
+```csharp
+// 安装清理
+FileSystemParametersDefine.INSTALL_CLEAR_MODE              // EOverwriteInstallClearMode
+
+// 文件校验
+FileSystemParametersDefine.FILE_VERIFY_LEVEL               // EFileVerifyLevel
+FileSystemParametersDefine.FILE_VERIFY_MAX_CONCURRENCY     // int
+
+// 文件配置
+FileSystemParametersDefine.APPEND_FILE_EXTENSION           // bool
+FileSystemParametersDefine.DISABLE_CATALOG_FILE            // bool
+
+// 清单拷贝
+FileSystemParametersDefine.COPY_BUILDIN_PACKAGE_MANIFEST   // bool
+FileSystemParametersDefine.COPY_BUILDIN_PACKAGE_MANIFEST_DEST_ROOT  // string
+
+// 解压配置
+FileSystemParametersDefine.UNPACK_FILE_SYSTEM_ROOT         // string
+
+// 服务接口
+FileSystemParametersDefine.DECRYPTION_SERVICES             // IDecryptionServices
+FileSystemParametersDefine.MANIFEST_SERVICES               // IManifestRestoreServices
+FileSystemParametersDefine.COPY_LOCAL_FILE_SERVICES        // ICopyLocalFileServices
+```
+
+---
+
+## 类继承关系
+
+```
+IFileSystem
+    └── DefaultBuildinFileSystem
+            └── (内部持有) DefaultUnpackFileSystem
+
+FSInitializeFileSystemOperation
+    └── DBFSInitializeOperation
+
+FSRequestPackageVersionOperation
+    └── DBFSRequestPackageVersionOperation
+
+FSLoadPackageManifestOperation
+    └── DBFSLoadPackageManifestOperation
+
+FSLoadBundleOperation
+    ├── DBFSLoadAssetBundleOperation
+    ├── DBFSLoadRawBundleOperation
+    └── DBFSLoadInstantBundleOperation (Tuanjie)
+
+AsyncOperationBase
+    ├── LoadBuildinCatalogFileOperation
+    ├── CopyBuildinFileOperation
+    ├── LoadBuildinPackageManifestOperation
+    ├── RequestBuildinPackageHashOperation
+    └── RequestBuildinPackageVersionOperation
+
+BundleResult
+    ├── AssetBundleResult  ← AssetBundle 资源
+    └── RawBundleResult    ← 原生文件
+```
+
+---
+
+## 注意事项
+
+1. **WebGL 不支持**：DefaultBuildinFileSystem 不支持 WebGL 平台
+2. **Android 限制**：Android 平台无法直接读取 StreamingAssets 中的原生文件
+3. **Catalog 文件**：构建时需要生成 Catalog 文件，否则需要禁用 Catalog 功能
+4. **解压目录**：解压的文件存储在 `UnpackFileSystemRoot` 指定的目录
+5. **加密资源**：加密资源在 Android/OpenHarmony 平台会自动解压到沙盒
+6. **清单拷贝**：启用清单拷贝可以支持从离线模式平滑切换到联机模式

Assets/YooAsset/Runtime/FileSystem/DefaultBuildinFileSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 7ec531875d1515b4496e0e9035e63661
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/DefaultCacheFileSystem.cs

@@ -23,10 +23,14 @@ namespace YooAsset
         protected string _cacheManifestFilesRoot;
 
         /// <summary>
-        /// 下载中心
+        /// 下载调度器
-        /// 说明：当异步操作任务终止的时候，所有下载子任务都会一同被终止！
         /// </summary>
-        public DownloadCenterOperation DownloadCenter { set; get; }
+        public DownloadSchedulerOperation DownloadScheduler { set; get; }
+
+        /// <summary>
+        /// 下载后台接口
+        /// </summary>
+        public IDownloadBackend DownloadBackend { private set; get; }
 
         /// <summary>
         /// 包裹名称
@@ -56,6 +60,11 @@ namespace YooAsset
         }
 
         #region 自定义参数
+        /// <summary>
+        /// 自定义参数：UnityWebRequest 创建委托
+        /// </summary>
+        public UnityWebRequestCreator WebRequestCreator { private set; get; }
+
         /// <summary>
         /// 自定义参数：远程服务接口的实例类
         /// </summary>
@@ -73,8 +82,10 @@ namespace YooAsset
 
         /// <summary>
         /// 自定义参数：初始化的时候缓存文件校验最大并发数
+        /// 默认值：32（推荐范围 1-128）
+        /// 说明：过大的值可能导致线程池任务过多，影响系统稳定性 
         /// </summary>
-        public int FileVerifyMaxConcurrency { private set; get; } = int.MaxValue;
+        public int FileVerifyMaxConcurrency { private set; get; } = 32;
 
         /// <summary>
         /// 自定义参数：数据文件追加文件格式
@@ -88,18 +99,22 @@ namespace YooAsset
 
         /// <summary>
         /// 自定义参数：最大并发连接数
+        /// 默认值：10（推荐范围 1-32）
+        /// 说明：过大的并发数可能被服务器限流，也会增加本地资源消耗 
         /// </summary>
-        public int DownloadMaxConcurrency { private set; get; } = int.MaxValue;
+        public int DownloadMaxConcurrency { private set; get; } = 10;
 
         /// <summary>
         /// 自定义参数：每帧发起的最大请求数
+        /// 默认值：5（推荐范围 1-10） 
+        /// 说明：避免单帧发起过多请求导致卡顿 
         /// </summary>
-        public int DownloadMaxRequestPerFrame { private set; get; } = int.MaxValue;
+        public int DownloadMaxRequestPerFrame { private set; get; } = 5;
 
         /// <summary>
         /// 自定义参数：下载任务的看门狗机制监控时间
         /// </summary>
-        public int DownloadWatchDogTime { private set; get; } = int.MaxValue;
+        public int DownloadWatchDogTime { private set; get; } = 0;
 
         /// <summary>
         /// 自定义参数：启用断点续传的最小尺寸
@@ -227,7 +242,15 @@ namespace YooAsset
 
         public virtual void SetParameter(string name, object value)
         {
-            if (name == FileSystemParametersDefine.REMOTE_SERVICES)
+            if (name == FileSystemParametersDefine.DOWNLOAD_BACKEND)
+            {
+                DownloadBackend = (IDownloadBackend)value;
+            }
+            else if (name == FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR)
+            {
+                WebRequestCreator = (UnityWebRequestCreator)value;
+            }
+            else if (name == FileSystemParametersDefine.REMOTE_SERVICES)
             {
                 RemoteServices = (IRemoteServices)value;
             }
@@ -242,7 +265,14 @@ namespace YooAsset
             else if (name == FileSystemParametersDefine.FILE_VERIFY_MAX_CONCURRENCY)
             {
                 int convertValue = Convert.ToInt32(value);
-                FileVerifyMaxConcurrency = Mathf.Clamp(convertValue, 1, int.MaxValue);
+                if (convertValue > 256)
+                {
+                    YooLogger.Warning($"FILE_VERIFY_MAX_CONCURRENCY value {convertValue} is too large, clamped to 256. Recommended range: 1 - 128.");
+                }
+
+                // 限制在合理范围内：1-256                                                                             
+                // 超过 256 的并发数对于文件验证来说没有意义，反而会增加线程池压力  
+                FileVerifyMaxConcurrency = Mathf.Clamp(convertValue, 1, 256);
             }
             else if (name == FileSystemParametersDefine.APPEND_FILE_EXTENSION)
             {
@@ -255,17 +285,27 @@ namespace YooAsset
             else if (name == FileSystemParametersDefine.DOWNLOAD_MAX_CONCURRENCY)
             {
                 int convertValue = Convert.ToInt32(value);
-                DownloadMaxConcurrency = Mathf.Clamp(convertValue, 1, int.MaxValue);
+                if (convertValue > 64)
+                {
+                    YooLogger.Warning($"DOWNLOAD_MAX_CONCURRENCY value {convertValue} is too large, clamped to 64. Recommended range: 1 - 32.");
+                }
+
+                DownloadMaxConcurrency = Mathf.Clamp(convertValue, 1, 64);
             }
             else if (name == FileSystemParametersDefine.DOWNLOAD_MAX_REQUEST_PER_FRAME)
             {
                 int convertValue = Convert.ToInt32(value);
-                DownloadMaxRequestPerFrame = Mathf.Clamp(convertValue, 1, int.MaxValue);
+                if (convertValue > 20)
+                {
+                    YooLogger.Warning($"DOWNLOAD_MAX_REQUEST_PER_FRAME value {convertValue} is too large, clamped to 20. Recommended range: 1 - 10.");
+                }
+
+                DownloadMaxRequestPerFrame = Mathf.Clamp(convertValue, 1, 20);
             }
             else if (name == FileSystemParametersDefine.DOWNLOAD_WATCH_DOG_TIME)
             {
                 int convertValue = Convert.ToInt32(value);
-                DownloadWatchDogTime = Mathf.Clamp(convertValue, 1, int.MaxValue);
+                DownloadWatchDogTime = Mathf.Clamp(convertValue, 0, int.MaxValue);
             }
             else if (name == FileSystemParametersDefine.RESUME_DOWNLOAD_MINMUM_SIZE)
             {
@@ -304,13 +344,23 @@ namespace YooAsset
             _cacheBundleFilesRoot = PathUtility.Combine(_packageRoot, DefaultCacheFileSystemDefine.BundleFilesFolderName);
             _cacheManifestFilesRoot = PathUtility.Combine(_packageRoot, DefaultCacheFileSystemDefine.ManifestFilesFolderName);
             _tempFilesRoot = PathUtility.Combine(_packageRoot, DefaultCacheFileSystemDefine.TempFilesFolderName);
+
+            // 创建默认的下载后台接口
+            if (DownloadBackend == null)
+                DownloadBackend = new UnityWebRequestBackend(WebRequestCreator);
         }
         public virtual void OnDestroy()
         {
-            if (DownloadCenter != null)
+            if (DownloadScheduler != null)
             {
-                DownloadCenter.AbortOperation();
+                DownloadScheduler.Dispose();
-                DownloadCenter = null;
+                DownloadScheduler = null;
+            }
+
+            if (DownloadBackend != null)
+            {
+                DownloadBackend.Dispose();
+                DownloadBackend = null;
             }
         }
 
@@ -476,7 +526,7 @@ namespace YooAsset
         {
             if (_records.ContainsKey(bundle.BundleGUID))
             {
-                throw new Exception("Should never get here !");
+                throw new YooInternalException();
             }
 
             string infoFilePath = GetBundleInfoFilePath(bundle);
@@ -498,9 +548,9 @@ namespace YooAsset
                 // 写入文件信息
                 WriteBundleInfoFile(infoFilePath, bundle.FileCRC, bundle.FileSize);
             }
-            catch (Exception e)
+            catch (Exception ex)
             {
-                YooLogger.Error($"Failed to write cache file ! {e.Message}");
+                YooLogger.Error($"Failed to write cache file ! {ex.Message}");
                 return false;
             }
 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Elements/RecordFileElement.cs

@@ -37,9 +37,9 @@ namespace YooAsset
                     return false;
                 }
             }
-            catch (Exception e)
+            catch (Exception ex)
             {
-                YooLogger.Error($"Failed to delete cache file ! {e.Message}");
+                YooLogger.Error($"Failed to delete cache file ! {ex.Message}");
                 return false;
             }
         }

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Elements/VerifyFileElement.cs

@@ -33,9 +33,9 @@ namespace YooAsset
             {
                 Directory.Delete(FileRootPath, true);
             }
-            catch (System.Exception e)
+            catch (System.Exception ex)
             {
-                YooLogger.Warning($"Failed to delete cache bundle folder : {e}");
+                YooLogger.Warning($"Failed to delete cache bundle folder : {ex}");
             }
         }
     }

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/DCFSInitializeOperation.cs

@@ -9,7 +9,7 @@ namespace YooAsset
             CheckAppFootPrint,
             SearchCacheFiles,
             VerifyCacheFiles,
-            CreateDownloadCenter,
+            CreateDownloadScheduler,
             Done,
         }
 
@@ -110,7 +110,7 @@ namespace YooAsset
 
                 if (_verifyCacheFilesOp.Status == EOperationStatus.Succeed)
                 {
-                    _steps = ESteps.CreateDownloadCenter;
+                    _steps = ESteps.CreateDownloadScheduler;
                     YooLogger.Log($"Package '{_fileSystem.PackageName}' '{_fileSystem.GetType().Name}' cached files count : {_fileSystem.FileCount}");
                 }
                 else
@@ -121,13 +121,13 @@ namespace YooAsset
                 }
             }
 
-            if (_steps == ESteps.CreateDownloadCenter)
+            if (_steps == ESteps.CreateDownloadScheduler)
             {
                 // 注意：下载中心作为独立任务运行！
-                if (_fileSystem.DownloadCenter == null)
+                if (_fileSystem.DownloadScheduler == null)
                 {
-                    _fileSystem.DownloadCenter = new DownloadCenterOperation(_fileSystem);
+                    _fileSystem.DownloadScheduler = new DownloadSchedulerOperation(_fileSystem);
-                    OperationSystem.StartOperation(_fileSystem.PackageName, _fileSystem.DownloadCenter);
+                    OperationSystem.StartOperation(_fileSystem.PackageName, _fileSystem.DownloadScheduler);
                 }
 
                 _steps = ESteps.Done;

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/DCFSLoadBundleOperation.cs

@@ -320,11 +320,11 @@ namespace YooAsset
                             File.Move(recordFileElement.DataFilePath, filePath);
                             _steps = ESteps.LoadCacheRawBundle;
                         }
-                        catch (Exception e)
+                        catch (Exception ex)
                         {
                             _steps = ESteps.Done;
                             Status = EOperationStatus.Failed;
-                            Error = $"Faild rename raw data file : {e.Message}";
+                            Error = $"Faild rename raw data file : {ex.Message}";
                         }
                     }
                     else

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadCenterOperation.cs

@@ -1,133 +0,0 @@
-using System;
-using System.Collections.Generic;
-
-namespace YooAsset
-{
-    internal class DownloadCenterOperation : AsyncOperationBase
-    {
-        private readonly DefaultCacheFileSystem _fileSystem;
-        protected readonly Dictionary<string, UnityDownloadFileOperation> _downloaders = new Dictionary<string, UnityDownloadFileOperation>(1000);
-        protected readonly List<string> _removeList = new List<string>(1000);
-
-        public DownloadCenterOperation(DefaultCacheFileSystem fileSystem)
-        {
-            _fileSystem = fileSystem;
-        }
-        internal override void InternalStart()
-        {
-        }
-        internal override void InternalUpdate()
-        {
-            // 获取可移除的下载器集合
-            _removeList.Clear();
-            foreach (var valuePair in _downloaders)
-            {
-                var downloader = valuePair.Value;
-                downloader.UpdateOperation();
-                if (downloader.IsDone)
-                {
-                    _removeList.Add(valuePair.Key);
-                    continue;
-                }
-
-                // 注意：主动终止引用计数为零的下载任务
-                if (downloader.RefCount <= 0)
-                {
-                    _removeList.Add(valuePair.Key);
-                    downloader.AbortOperation();
-                    continue;
-                }
-            }
-
-            // 移除下载器
-            foreach (var key in _removeList)
-            {
-                if (_downloaders.TryGetValue(key, out var downloader))
-                {
-                    Childs.Remove(downloader);
-                    _downloaders.Remove(key);
-                }
-            }
-
-            // 最大并发数检测
-            int processCount = GetProcessingOperationCount();
-            if (processCount != _downloaders.Count)
-            {
-                if (processCount < _fileSystem.DownloadMaxConcurrency)
-                {
-                    int startCount = _fileSystem.DownloadMaxConcurrency - processCount;
-                    if (startCount > _fileSystem.DownloadMaxRequestPerFrame)
-                        startCount = _fileSystem.DownloadMaxRequestPerFrame;
-
-                    foreach (var operationPair in _downloaders)
-                    {
-                        var operation = operationPair.Value;
-                        if (operation.Status == EOperationStatus.None)
-                        {
-                            operation.StartOperation();
-                            startCount--;
-                            if (startCount <= 0)
-                                break;
-                        }
-                    }
-                }
-            }
-        }
-
-        /// <summary>
-        /// 创建下载任务
-        /// </summary>
-        public UnityDownloadFileOperation DownloadFileAsync(PackageBundle bundle, string url)
-        {
-            // 查询旧的下载器
-            if (_downloaders.TryGetValue(bundle.BundleGUID, out var oldDownloader))
-            {
-                oldDownloader.Reference();
-                return oldDownloader;
-            }
-
-            // 创建新的下载器
-            UnityDownloadFileOperation newDownloader;
-            bool isRequestLocalFile = DownloadSystemHelper.IsRequestLocalFile(url);
-            if (isRequestLocalFile)
-            {
-                newDownloader = new UnityDownloadLocalFileOperation(_fileSystem, bundle, url);
-                AddChildOperation(newDownloader);
-                _downloaders.Add(bundle.BundleGUID, newDownloader);
-            }
-            else
-            {
-                if (bundle.FileSize >= _fileSystem.ResumeDownloadMinimumSize)
-                {
-                    newDownloader = new UnityDownloadResumeFileOperation(_fileSystem, bundle, url);
-                    AddChildOperation(newDownloader);
-                    _downloaders.Add(bundle.BundleGUID, newDownloader);
-                }
-                else
-                {
-                    newDownloader = new UnityDownloadNormalFileOperation(_fileSystem, bundle, url);
-                    AddChildOperation(newDownloader);
-                    _downloaders.Add(bundle.BundleGUID, newDownloader);
-                }
-            }
-
-            newDownloader.Reference();
-            return newDownloader;
-        }
-
-        /// <summary>
-        /// 获取正在进行中的下载器总数
-        /// </summary>
-        private int GetProcessingOperationCount()
-        {
-            int count = 0;
-            foreach (var operationPair in _downloaders)
-            {
-                var operation = operationPair.Value;
-                if (operation.Status != EOperationStatus.None)
-                    count++;
-            }
-            return count;
-        }
-    }
-}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadCenterOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 768ef2df3433df245a26fec28d022e45
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageBundleOperation.cs

@@ -1,4 +1,5 @@
-using UnityEngine;
+using System.IO;
+using UnityEngine;
 
 namespace YooAsset
 {
@@ -17,7 +18,7 @@ namespace YooAsset
         // 下载参数
         protected readonly DefaultCacheFileSystem _fileSystem;
         protected readonly DownloadFileOptions _options;
-        private UnityDownloadFileOperation _unityDownloadFileOp;
+        private DownloadAndCacheFileOperation _downloadFileOp;
 
         protected int _requestCount = 0;
         protected float _tryAgainTimer = 0;
@@ -67,7 +68,7 @@ namespace YooAsset
                 }
 
                 string url = GetRequestURL();
-                _unityDownloadFileOp = _fileSystem.DownloadCenter.DownloadFileAsync(Bundle, url);
+                _downloadFileOp = _fileSystem.DownloadScheduler.DownloadAndCacheFileAsync(Bundle, url);
                 _steps = ESteps.CheckRequest;
             }
 
@@ -75,20 +76,16 @@ namespace YooAsset
             if (_steps == ESteps.CheckRequest)
             {
                 if (IsWaitForAsyncComplete)
-                    _unityDownloadFileOp.WaitForAsyncComplete();
+                    _downloadFileOp.WaitForAsyncComplete();
 
-                // 因为并发数量限制，下载器可能被挂起！
+                _downloadFileOp.UpdateOperation();
-                if (_unityDownloadFileOp.Status == EOperationStatus.None)
+                Progress = _downloadFileOp.Progress;
+                DownloadedBytes = _downloadFileOp.DownloadedBytes;
+                DownloadProgress = _downloadFileOp.DownloadProgress;
+                if (_downloadFileOp.IsDone == false)
                     return;
 
-                _unityDownloadFileOp.UpdateOperation();
+                if (_downloadFileOp.Status == EOperationStatus.Succeed)
-                Progress = _unityDownloadFileOp.Progress;
-                DownloadedBytes = _unityDownloadFileOp.DownloadedBytes;
-                DownloadProgress = _unityDownloadFileOp.DownloadProgress;
-                if (_unityDownloadFileOp.IsDone == false)
-                    return;
-
-                if (_unityDownloadFileOp.Status == EOperationStatus.Succeed)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;
@@ -98,13 +95,13 @@ namespace YooAsset
                     if (IsWaitForAsyncComplete == false && _failedTryAgain > 0)
                     {
                         _steps = ESteps.TryAgain;
-                        YooLogger.Warning($"Failed download : {_unityDownloadFileOp.URL} Try again !");
+                        YooLogger.Warning($"Failed download : {_downloadFileOp.URL} Try again !");
                     }
                     else
                     {
                         _steps = ESteps.Done;
                         Status = EOperationStatus.Failed;
-                        Error = _unityDownloadFileOp.Error;
+                        Error = _downloadFileOp.Error;
                         YooLogger.Error(Error);
                     }
                 }
@@ -141,9 +138,9 @@ namespace YooAsset
             // 注意：取消下载任务的时候引用计数减一
             if (_steps != ESteps.Done)
             {
-                if (_unityDownloadFileOp != null)
+                if (_downloadFileOp != null)
                 {
-                    _unityDownloadFileOp.Release();
+                    _downloadFileOp.Release();
                 }
             }
         }

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageHashOperation.cs

@@ -15,7 +15,7 @@ namespace YooAsset
         private readonly DefaultCacheFileSystem _fileSystem;
         private readonly string _packageVersion;
         private readonly int _timeout;
-        private UnityWebFileRequestOperation _webFileRequestOp;
+        private IDownloadFileRequest _webFileRequestOp;
         private int _requestCount = 0;
         private ESteps _steps = ESteps.None;
 
@@ -57,16 +57,16 @@ namespace YooAsset
                     string savePath = _fileSystem.GetCachePackageHashFilePath(_packageVersion);
                     string fileName = YooAssetSettingsData.GetPackageHashFileName(_fileSystem.PackageName, _packageVersion);
                     string webURL = GetWebRequestURL(fileName);
-                    _webFileRequestOp = new UnityWebFileRequestOperation(webURL, savePath, _timeout);
+                    int watchdogTime = _fileSystem.DownloadWatchDogTime;
-                    _webFileRequestOp.StartOperation();
+                    var args = new DownloadFileRequestArgs(webURL, savePath, _timeout, watchdogTime);
-                    AddChildOperation(_webFileRequestOp);
+                    _webFileRequestOp = _fileSystem.DownloadBackend.CreateFileRequest(args);
+                    _webFileRequestOp.SendRequest();
                 }
 
-                _webFileRequestOp.UpdateOperation();
                 if (_webFileRequestOp.IsDone == false)
                     return;
 
-                if (_webFileRequestOp.Status == EOperationStatus.Succeed)
+                if (_webFileRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/DownloadPackageManifestOperation.cs

@@ -15,7 +15,7 @@ namespace YooAsset
         private readonly DefaultCacheFileSystem _fileSystem;
         private readonly string _packageVersion;
         private readonly int _timeout;
-        private UnityWebFileRequestOperation _webFileRequestOp;
+        private IDownloadFileRequest _webFileRequestOp;
         private int _requestCount = 0;
         private ESteps _steps = ESteps.None;
 
@@ -57,16 +57,16 @@ namespace YooAsset
                     string savePath = _fileSystem.GetCachePackageManifestFilePath(_packageVersion);
                     string fileName = YooAssetSettingsData.GetManifestBinaryFileName(_fileSystem.PackageName, _packageVersion);
                     string webURL = GetDownloadRequestURL(fileName);
-                    _webFileRequestOp = new UnityWebFileRequestOperation(webURL, savePath, _timeout);
+                    int watchdogTime = _fileSystem.DownloadWatchDogTime;
-                    _webFileRequestOp.StartOperation();
+                    var args = new DownloadFileRequestArgs(webURL, savePath, _timeout, watchdogTime);
-                    AddChildOperation(_webFileRequestOp);
+                    _webFileRequestOp = _fileSystem.DownloadBackend.CreateFileRequest(args);
+                    _webFileRequestOp.SendRequest();
                 }
 
-                _webFileRequestOp.UpdateOperation();
                 if (_webFileRequestOp.IsDone == false)
                     return;
 
-                if (_webFileRequestOp.Status == EOperationStatus.Succeed)
+                if (_webFileRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/RequestRemotePackageVersionOperation.cs

@@ -13,7 +13,7 @@ namespace YooAsset
         private readonly DefaultCacheFileSystem _fileSystem;
         private readonly bool _appendTimeTicks;
         private readonly int _timeout;
-        private UnityWebTextRequestOperation _webTextRequestOp;
+        private IDownloadTextRequest _webTextRequestOp;
         private int _requestCount = 0;
         private ESteps _steps = ESteps.None;
 
@@ -45,17 +45,17 @@ namespace YooAsset
                 {
                     string fileName = YooAssetSettingsData.GetPackageVersionFileName(_fileSystem.PackageName);
                     string url = GetWebRequestURL(fileName);
-                    _webTextRequestOp = new UnityWebTextRequestOperation(url, _timeout);
+                    int watchDogTime = _fileSystem.DownloadWatchDogTime;
-                    _webTextRequestOp.StartOperation();
+                    var args = new DownloadDataRequestArgs(url, _timeout, watchDogTime);
-                    AddChildOperation(_webTextRequestOp);
+                    _webTextRequestOp = _fileSystem.DownloadBackend.CreateTextRequest(args);
+                    _webTextRequestOp.SendRequest();
                 }
 
-                _webTextRequestOp.UpdateOperation();
+                Progress = _webTextRequestOp.DownloadProgress;
-                Progress = _webTextRequestOp.Progress;
                 if (_webTextRequestOp.IsDone == false)
                     return;
 
-                if (_webTextRequestOp.Status == EOperationStatus.Succeed)
+                if (_webTextRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     PackageVersion = _webTextRequestOp.Result;
                     if (string.IsNullOrEmpty(PackageVersion))

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: bf9991076b60f0f459846f54b0ca6698
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheFileOperation.cs

@@ -0,0 +1,51 @@
+
+namespace YooAsset
+{
+    internal abstract class DownloadAndCacheFileOperation : AsyncOperationBase
+    {
+        /// <summary>
+        /// 引用计数
+        /// </summary>
+        public int RefCount { private set; get; }
+
+        /// <summary>
+        /// 下载地址
+        /// </summary>
+        public readonly string URL;
+
+        /// <summary>
+        /// 下载进度
+        /// </summary>
+        public float DownloadProgress { get; protected set; }
+
+        /// <summary>
+        /// 下载字节
+        /// </summary>
+        public long DownloadedBytes { get; protected set; }
+
+        public DownloadAndCacheFileOperation(string url)
+        {
+            URL = url;
+        }
+        internal override string InternalGetDesc()
+        {
+            return $"RefCount : {RefCount}";
+        }
+
+        /// <summary>
+        /// 减少引用计数
+        /// </summary>
+        public void Release()
+        {
+            RefCount--;
+        }
+
+        /// <summary>
+        /// 增加引用计数
+        /// </summary>
+        public void Reference()
+        {
+            RefCount++;
+        }
+    }
+}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheFileOperation.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 2954a64fd419d5a4b9d0a102260d193c
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheLocalFileOperation.cs

@@ -1,94 +1,79 @@
 using System.IO;
-using UnityEngine;
-using UnityEngine.Networking;
 
 namespace YooAsset
 {
-    internal sealed class UnityDownloadLocalFileOperation : UnityDownloadFileOperation
+    internal sealed class DownloadAndCacheLocalFileOperation : DownloadAndCacheFileOperation
     {
+        private enum ESteps
+        {
+            None,
+            CheckCopy,
+            CopyLocalFile,
+            CreateRequest,
+            CheckRequest,
+            VerifyBundleFile,
+            CacheBundleFile,
+            Done,
+        }
+
+        private readonly DefaultCacheFileSystem _fileSystem;
+        private readonly PackageBundle _bundle;
+        private readonly string _tempFilePath;
+        private IDownloadRequest _request;
         private VerifyTempFileOperation _verifyOperation;
         private ESteps _steps = ESteps.None;
 
-        internal UnityDownloadLocalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url)
+        internal DownloadAndCacheLocalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url) : base(url)
-            : base(fileSystem, bundle, url)
         {
+            _fileSystem = fileSystem;
+            _bundle = bundle;
+            _tempFilePath = _fileSystem.GetTempFilePath(_bundle);
         }
         internal override void InternalStart()
         {
-            if (_fileSystem.CopyLocalFileServices != null)
+            _steps = ESteps.CheckCopy;
-                _steps = ESteps.CopyLocalFile;
-            else
-                _steps = ESteps.CreateRequest;
         }
         internal override void InternalUpdate()
         {
             if (_steps == ESteps.None || _steps == ESteps.Done)
                 return;
 
-            // 创建下载器
+            // 检测文件拷贝
-            if (_steps == ESteps.CreateRequest)
+            if (_steps == ESteps.CheckCopy)
             {
+                // 删除历史缓存文件
                 FileUtility.CreateFileDirectory(_tempFilePath);
                 if (File.Exists(_tempFilePath))
                     File.Delete(_tempFilePath);
 
-                CreateWebRequest();
+                if (_fileSystem.CopyLocalFileServices != null)
-                _steps = ESteps.Download;
+                    _steps = ESteps.CopyLocalFile;
-            }
-
-            // 检测下载结果
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-
-                UpdateWatchDog();
-                if (_webRequest.isDone == false)
-                    return;
-
-                // 检查网络错误
-                if (CheckRequestResult())
-                {
-                    _steps = ESteps.VerifyFile;
-                }
                 else
-                {
+                    _steps = ESteps.CreateRequest;
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
             }
 
-                // 注意：最终释放请求器
+            // 拷贝本地文件
-                DisposeRequest();
-            }
-
-            // 拷贝内置文件
             if (_steps == ESteps.CopyLocalFile)
             {
-                FileUtility.CreateFileDirectory(_tempFilePath);
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-
                 try
                 {
                     //TODO 团结引擎，在某些机型（红米），拷贝包内文件会小概率失败！需要借助其它方式来拷贝包内文件。
                     var localFileInfo = new LocalFileInfo();
                     localFileInfo.PackageName = _fileSystem.PackageName;
                     localFileInfo.BundleName = _bundle.BundleName;
-                    localFileInfo.SourceFileURL = _requestURL;
+                    localFileInfo.SourceFileURL = URL;
                     _fileSystem.CopyLocalFileServices.CopyFile(localFileInfo, _tempFilePath);
                     if (File.Exists(_tempFilePath))
                     {
                         DownloadProgress = 1f;
                         DownloadedBytes = _bundle.FileSize;
-                        Progress = DownloadProgress;
+                        _steps = ESteps.VerifyBundleFile;
-                        _steps = ESteps.VerifyFile;
                     }
                     else
                     {
                         _steps = ESteps.Done;
                         Status = EOperationStatus.Failed;
-                        Error = $"Failed copy local file : {_requestURL}";
+                        Error = $"Failed copy local file : {URL}";
                     }
                 }
                 catch (System.Exception ex)
@@ -99,8 +84,44 @@ namespace YooAsset
                 }
             }
 
-            // 验证下载文件
+            // 创建下载请求
-            if (_steps == ESteps.VerifyFile)
+            if (_steps == ESteps.CreateRequest)
+            {
+                int watchdogTime = _fileSystem.DownloadWatchDogTime;
+                int timeout = 0; //注意：文件下载不做超时检测
+                var args = new DownloadFileRequestArgs(URL, _tempFilePath, timeout, watchdogTime);
+                _request = _fileSystem.DownloadBackend.CreateFileRequest(args);
+                _request.SendRequest();
+                _steps = ESteps.CheckRequest;
+            }
+
+            // 检测下载结果
+            if (_steps == ESteps.CheckRequest)
+            {
+                DownloadProgress = _request.DownloadProgress;
+                DownloadedBytes = _request.DownloadedBytes;
+                Progress = DownloadProgress;
+                if (_request.IsDone == false)
+                    return;
+
+                // 检查网络错误
+                if (_request.Status == EDownloadRequestStatus.Succeed)
+                {
+                    _steps = ESteps.VerifyBundleFile;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = _request.Error;
+                }
+
+                // 最终释放请求器
+                _request.Dispose();
+            }
+
+            // 验证下载结果
+            if (_steps == ESteps.VerifyBundleFile)
             {
                 if (_verifyOperation == null)
                 {
@@ -118,6 +139,23 @@ namespace YooAsset
                     return;
 
                 if (_verifyOperation.Status == EOperationStatus.Succeed)
+                {
+                    _steps = ESteps.CacheBundleFile;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = _verifyOperation.Error;
+
+                    // 注意：验证失败后直接删除文件
+                    if (File.Exists(_tempFilePath))
+                        File.Delete(_tempFilePath);
+                }
+            }
+
+            // 缓存文件
+            if (_steps == ESteps.CacheBundleFile)
             {
                 if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
                 {
@@ -130,41 +168,32 @@ namespace YooAsset
                     Status = EOperationStatus.Failed;
                     Error = $"{_fileSystem.GetType().FullName} failed to write file !";
                 }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                    Error = _verifyOperation.Error;
-                }
 
-                // 注意：验证完成后直接删除文件
+                // 注意：缓存完成后直接删除临时文件
                 if (File.Exists(_tempFilePath))
                     File.Delete(_tempFilePath);
             }
         }
+        internal override void InternalAbort()
+        {
+            if (_request != null)
+                _request.AbortRequest();
+        }
         internal override void InternalWaitForAsyncComplete()
         {
             while (true)
             {
+                //TODO 更新下载后台，防止无限挂起
+                _fileSystem.DownloadBackend.Update();
+
                 //TODO 等待导入或解压本地文件完毕，该操作会挂起主线程！
                 InternalUpdate();
                 if (IsDone)
                     break;
 
-                // 短暂休眠避免完全卡死
+                //TODO 短暂休眠避免完全卡死
                 System.Threading.Thread.Sleep(1);
             }
         }
-
-        private void CreateWebRequest()
-        {
-            DownloadHandlerFile handler = new DownloadHandlerFile(_tempFilePath);
-            handler.removeFileOnAbort = true;
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _webRequest.SendWebRequest();
-        }
     }
 }

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheLocalFileOperation.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 47700ac672942834f8d5a7c59783d88e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheRemoteFileOperation.cs

@@ -0,0 +1,206 @@
+using System.IO;
+
+namespace YooAsset
+{
+    internal sealed class DownloadAndCacheRemoteFileOperation : DownloadAndCacheFileOperation
+    {
+        private enum ESteps
+        {
+            None,
+            CreateRequest,
+            CheckRequest,
+            VerifyBundleFile,
+            CacheBundleFile,
+            Done,
+        }
+
+        private readonly DefaultCacheFileSystem _fileSystem;
+        private readonly PackageBundle _bundle;
+        private readonly string _tempFilePath;
+        private bool _enableResume = false;
+        private long _fileOriginLength = 0;
+        private IDownloadRequest _request;
+        private VerifyTempFileOperation _verifyOperation;
+        private ESteps _steps = ESteps.None;
+
+        internal DownloadAndCacheRemoteFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url) : base(url)
+        {
+            _fileSystem = fileSystem;
+            _bundle = bundle;
+            _tempFilePath = _fileSystem.GetTempFilePath(_bundle);
+        }
+        internal override void InternalStart()
+        {
+            _steps = ESteps.CreateRequest;
+        }
+        internal override void InternalUpdate()
+        {
+            if (_steps == ESteps.None || _steps == ESteps.Done)
+                return;
+
+            // 创建下载请求
+            if (_steps == ESteps.CreateRequest)
+            {
+                FileUtility.CreateFileDirectory(_tempFilePath);
+
+                _enableResume = _bundle.FileSize >= _fileSystem.ResumeDownloadMinimumSize;
+                if (_enableResume)
+                {
+                    _request = CreateResumeRequest();
+                    _request.SendRequest();
+                    _steps = ESteps.CheckRequest;
+                }
+                else
+                {
+                    _request = CreateNormalRequest();
+                    _request.SendRequest();
+                    _steps = ESteps.CheckRequest;
+                }
+            }
+
+            // 检测下载结果
+            if (_steps == ESteps.CheckRequest)
+            {
+                DownloadProgress = _request.DownloadProgress;
+                DownloadedBytes = _fileOriginLength + _request.DownloadedBytes;
+                Progress = DownloadProgress;
+                if (_request.IsDone == false)
+                    return;
+
+                // 检查网络错误
+                if (_request.Status == EDownloadRequestStatus.Succeed)
+                {
+                    _steps = ESteps.VerifyBundleFile;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = _request.Error;
+                }
+
+                // 在遇到特殊错误的时候删除文件
+                if (_enableResume)
+                    ClearTempFileWhenError(_request.HttpCode);
+
+                // 最终释放请求器
+                _request.Dispose();
+            }
+
+            // 验证下载结果
+            if (_steps == ESteps.VerifyBundleFile)
+            {
+                if (_verifyOperation == null)
+                {
+                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
+                    _verifyOperation = new VerifyTempFileOperation(element);
+                    _verifyOperation.StartOperation();
+                    AddChildOperation(_verifyOperation);
+                }
+
+                if (IsWaitForAsyncComplete)
+                    _verifyOperation.WaitForAsyncComplete();
+
+                _verifyOperation.UpdateOperation();
+                if (_verifyOperation.IsDone == false)
+                    return;
+
+                if (_verifyOperation.Status == EOperationStatus.Succeed)
+                {
+                    _steps = ESteps.CacheBundleFile;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = _verifyOperation.Error;
+
+                    // 注意：验证失败后直接删除文件
+                    if (File.Exists(_tempFilePath))
+                        File.Delete(_tempFilePath);
+                }
+            }
+
+            // 缓存文件
+            if (_steps == ESteps.CacheBundleFile)
+            {
+                if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Succeed;
+                }
+                else
+                {
+                    _steps = ESteps.Done;
+                    Status = EOperationStatus.Failed;
+                    Error = $"{_fileSystem.GetType().FullName} failed to write file !";
+                }
+
+                // 注意：缓存完成后直接删除临时文件
+                if (File.Exists(_tempFilePath))
+                    File.Delete(_tempFilePath);
+            }
+        }
+        internal override void InternalAbort()
+        {
+            if (_request != null)
+                _request.AbortRequest();
+        }
+        internal override void InternalWaitForAsyncComplete()
+        {
+            if (_steps != ESteps.Done)
+            {
+                // 注意：不中断下载任务，保持后台继续下载
+                YooLogger.Error($"Try load bundle {_bundle.BundleName} from remote : {URL} !");
+            }
+        }
+
+        private IDownloadRequest CreateResumeRequest()
+        {
+            // 获取下载起始位置
+            if (File.Exists(_tempFilePath))
+            {
+                FileInfo fileInfo = new FileInfo(_tempFilePath);
+                if (fileInfo.Length >= _bundle.FileSize)
+                {
+                    File.Delete(_tempFilePath);
+                }
+                else
+                {
+                    _fileOriginLength = fileInfo.Length;
+                }
+            }
+
+            int watchdogTime = _fileSystem.DownloadWatchDogTime;
+            int timeout = 0; //注意：文件下载不做超时检测
+            bool appendToFile = true;
+            bool removeFileOnAbort = false;
+            long resumeFromBytes = _fileOriginLength;
+            var args = new DownloadFileRequestArgs(URL, _tempFilePath, timeout, watchdogTime, appendToFile, removeFileOnAbort, resumeFromBytes);
+            return _fileSystem.DownloadBackend.CreateFileRequest(args);
+        }
+        private IDownloadRequest CreateNormalRequest()
+        {
+            // 删除历史缓存文件
+            if (File.Exists(_tempFilePath))
+                File.Delete(_tempFilePath);
+
+            int watchdogTime = _fileSystem.DownloadWatchDogTime;
+            int timeout = 0; //注意：文件下载不做超时检测
+            var args = new DownloadFileRequestArgs(URL, _tempFilePath, timeout, watchdogTime);
+            return _fileSystem.DownloadBackend.CreateFileRequest(args);
+        }
+        private void ClearTempFileWhenError(long httpCode)
+        {
+            if (_fileSystem.ResumeDownloadResponseCodes == null)
+                return;
+
+            //说明：如果遇到以下错误返回码，验证失败直接删除文件
+            if (_fileSystem.ResumeDownloadResponseCodes.Contains(httpCode))
+            {
+                if (File.Exists(_tempFilePath))
+                    File.Delete(_tempFilePath);
+            }
+        }
+    }
+}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadAndCacheRemoteFileOperation.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: ad910a81855976e44b4f1f09051910b0
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadSchedulerOperation.cs

@@ -0,0 +1,189 @@
+using System;
+using System.Collections.Generic;
+
+namespace YooAsset
+{
+    /// <summary>
+    /// 下载调度器
+    /// </summary>
+    /// <remarks>
+    /// 管理所有活跃的下载任务，控制并发数量。
+    /// </remarks>
+    internal class DownloadSchedulerOperation : AsyncOperationBase, IDisposable
+    {
+        private readonly DefaultCacheFileSystem _fileSystem;
+        private readonly Dictionary<string, DownloadAndCacheFileOperation> _downloaders = new Dictionary<string, DownloadAndCacheFileOperation>(1000);
+        private readonly List<string> _removeList = new List<string>(1000);
+
+        /// <summary>
+        /// 是否已暂停
+        /// </summary>
+        public bool Paused { get; private set; } = false;
+
+        /// <summary>
+        /// 当前活跃的下载任务数
+        /// </summary>
+        public int ActiveDownloadCount { get; private set; }
+
+        /// <summary>
+        /// 当前等待中的下载任务数
+        /// </summary>
+        public int PendingDownloadCount
+        {
+            get
+            {
+                return _downloaders.Count - ActiveDownloadCount;
+            }
+        }
+
+
+        /// <summary>
+        /// 构造下载中心
+        /// </summary>
+        public DownloadSchedulerOperation(DefaultCacheFileSystem fileSystem)
+        {
+            _fileSystem = fileSystem;
+        }
+        internal override void InternalStart()
+        {
+        }
+        internal override void InternalUpdate()
+        {
+            // 驱动下载后台
+            _fileSystem.DownloadBackend.Update();
+
+            // 获取可移除的下载器集合
+            _removeList.Clear();
+            foreach (var valuePair in _downloaders)
+            {
+                var downloader = valuePair.Value;
+                downloader.UpdateOperation();
+                if (downloader.IsDone)
+                {
+                    _removeList.Add(valuePair.Key);
+                    continue;
+                }
+
+                // 注意：主动终止引用计数为零的下载任务
+                if (downloader.RefCount <= 0)
+                {
+                    _removeList.Add(valuePair.Key);
+                    downloader.AbortOperation();
+                    continue;
+                }
+            }
+
+            // 移除下载器
+            foreach (var key in _removeList)
+            {
+                if (_downloaders.TryGetValue(key, out var downloader))
+                {
+                    RemoveChildOperation(downloader);
+                    _downloaders.Remove(key);
+                }
+            }
+
+            // 暂停时不启动新任务
+            if (Paused)
+                return;
+
+            // 最大并发数检测
+            ActiveDownloadCount = GetProcessingOperationCount();
+            if (ActiveDownloadCount != _downloaders.Count)
+            {
+                int maxConcurrency = _fileSystem.DownloadMaxConcurrency;
+                int maxRequestPerFrame = _fileSystem.DownloadMaxRequestPerFrame;
+                if (ActiveDownloadCount < maxConcurrency)
+                {
+                    int startCount = maxConcurrency - ActiveDownloadCount;
+                    if (startCount > maxRequestPerFrame)
+                        startCount = maxRequestPerFrame;
+
+                    foreach (var operationPair in _downloaders)
+                    {
+                        var operation = operationPair.Value;
+                        if (operation.Status == EOperationStatus.None)
+                        {
+                            operation.StartOperation();
+                            startCount--;
+                            if (startCount <= 0)
+                                break;
+                        }
+                    }
+                }
+            }
+        }
+        internal override string InternalGetDesc()
+        {
+            return $"{_fileSystem.GetType().FullName}";
+        }
+
+        /// <summary>
+        /// 中止所有下载任务
+        /// </summary>
+        public void AbortAll()
+        {
+            foreach (var valuePair in _downloaders)
+            {
+                valuePair.Value.AbortOperation();
+            }
+            _downloaders.Clear();
+        }
+
+        /// <summary>
+        /// 释放资源
+        /// </summary>
+        public void Dispose()
+        {
+            AbortAll();
+        }
+
+        /// <summary>
+        /// 创建下载任务
+        /// </summary>
+        /// <param name="bundle">资源包信息</param>
+        /// <param name="url">下载地址</param>
+        /// <returns>下载操作</returns>
+        public DownloadAndCacheFileOperation DownloadAndCacheFileAsync(PackageBundle bundle, string url)
+        {
+            // 查询旧的下载器
+            if (_downloaders.TryGetValue(bundle.BundleGUID, out var oldDownloader))
+            {
+                oldDownloader.Reference();
+                return oldDownloader;
+            }
+
+            // 创建新的下载器
+            DownloadAndCacheFileOperation newDownloader;
+            bool isRequestLocalFile = DownloadSystemHelper.IsRequestLocalFile(url);
+            if (isRequestLocalFile)
+            {
+                newDownloader = new DownloadAndCacheLocalFileOperation(_fileSystem, bundle, url);
+            }
+            else
+            {
+                newDownloader = new DownloadAndCacheRemoteFileOperation(_fileSystem, bundle, url);
+            }
+
+            AddChildOperation(newDownloader);
+            _downloaders.Add(bundle.BundleGUID, newDownloader);
+            newDownloader.Reference();
+            return newDownloader;
+        }
+
+        /// <summary>
+        /// 获取正在进行中的下载器总数
+        /// </summary>
+        private int GetProcessingOperationCount()
+        {
+            int count = 0;
+            foreach (var operationPair in _downloaders)
+            {
+                var operation = operationPair.Value;
+                if (operation.Status != EOperationStatus.None)
+                    count++;
+            }
+            return count;
+        }
+    }
+}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/Scheduler/DownloadSchedulerOperation.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 73441e829c36a36418f5d677e189e9f3
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs

@@ -1,98 +0,0 @@
-
-namespace YooAsset
-{
-    internal abstract class UnityDownloadFileOperation : UnityWebRequestOperation
-    {
-        protected enum ESteps
-        {
-            None,
-            CreateRequest,
-            Download,
-            CopyLocalFile,
-            VerifyFile,
-            Done,
-        }
-
-        protected readonly DefaultCacheFileSystem _fileSystem;
-        protected readonly PackageBundle _bundle;
-        protected readonly string _tempFilePath;
-
-        private bool _watchDogInit = false;
-        private bool _watchDogAborted = false;
-        private ulong _lastDownloadBytes;
-        private double _lastGetDataTime;
-
-        /// <summary>
-        /// 引用计数
-        /// </summary>
-        public int RefCount { private set; get; }
-
-        internal UnityDownloadFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url) : base(url)
-        {
-            _fileSystem = fileSystem;
-            _bundle = bundle;
-            _tempFilePath = _fileSystem.GetTempFilePath(bundle);
-        }
-        internal override string InternalGetDesc()
-        {
-            return $"RefCount : {RefCount}";
-        }
-
-        /// <summary>
-        /// 更新看门狗监测
-        /// 说明：监控时间范围内，如果没有接收到任何下载数据，那么直接终止任务！
-        /// </summary>
-        protected void UpdateWatchDog()
-        {
-            if (_fileSystem.DownloadWatchDogTime == int.MaxValue)
-                return;
-
-            if (_watchDogAborted)
-                return;
-
-#if UNITY_2020_3_OR_NEWER
-            double realtimeSinceStartup = UnityEngine.Time.realtimeSinceStartupAsDouble;
-#else
-            double realtimeSinceStartup = UnityEngine.Time.realtimeSinceStartup;
-#endif
-
-            if (_watchDogInit == false)
-            {
-                _watchDogInit = true;
-                _lastDownloadBytes = 0;
-                _lastGetDataTime = realtimeSinceStartup;
-            }
-
-            if (_webRequest.downloadedBytes != _lastDownloadBytes)
-            {
-                _lastDownloadBytes = _webRequest.downloadedBytes;
-                _lastGetDataTime = realtimeSinceStartup;
-            }
-            else
-            {
-                double deltaTime = realtimeSinceStartup - _lastGetDataTime;
-                if (deltaTime > _fileSystem.DownloadWatchDogTime)
-                {
-                    _watchDogAborted = true;
-                    InternalAbort(); //终止网络请求
-                }
-            }
-        }
-
-        /// <summary>
-        /// 减少引用计数
-        /// </summary>
-        public void Release()
-        {
-            RefCount--;
-        }
-
-        /// <summary>
-        /// 增加引用计数
-        /// </summary>
-        public void Reference()
-        {
-            RefCount++;
-        }
-    }
-}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadFileOperation.cs.meta

@@ -1,11 +0,0 @@
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-guid: 40bb5e9391f413c42ae70e48ca90c4b7
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadLocalFileOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: c68640bb1d36552469024324e3357bc2
-MonoImporter:
-  externalObjects: {}
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Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs

@@ -1,124 +0,0 @@
-using System.IO;
-using UnityEngine;
-using UnityEngine.Networking;
-
-namespace YooAsset
-{
-    internal sealed class UnityDownloadNormalFileOperation : UnityDownloadFileOperation
-    {
-        private VerifyTempFileOperation _verifyOperation;
-        private ESteps _steps = ESteps.None;
-
-        internal UnityDownloadNormalFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url)
-            : base(fileSystem, bundle, url)
-        {
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            // 创建下载器
-            if (_steps == ESteps.CreateRequest)
-            {
-                FileUtility.CreateFileDirectory(_tempFilePath);
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-
-                CreateWebRequest();
-                _steps = ESteps.Download;
-            }
-
-            // 检测下载结果
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-
-                UpdateWatchDog();
-                if (_webRequest.isDone == false)
-                    return;
-
-                // 检查网络错误
-                if (CheckRequestResult())
-                {
-                    _steps = ESteps.VerifyFile;
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-
-            // 验证下载文件
-            if (_steps == ESteps.VerifyFile)
-            {
-                if (_verifyOperation == null)
-                {
-                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
-                    _verifyOperation = new VerifyTempFileOperation(element);
-                    _verifyOperation.StartOperation();
-                    AddChildOperation(_verifyOperation);
-                }
-
-                if (IsWaitForAsyncComplete)
-                    _verifyOperation.WaitForAsyncComplete();
-
-                _verifyOperation.UpdateOperation();
-                if (_verifyOperation.IsDone == false)
-                    return;
-
-                if (_verifyOperation.Status == EOperationStatus.Succeed)
-                {
-                    if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Succeed;
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"{_fileSystem.GetType().FullName} failed to write file ! {_tempFilePath}";
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                    Error = _verifyOperation.Error;
-                }
-
-                // 注意：验证完成后直接删除文件
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-            }
-        }
-        internal override void InternalWaitForAsyncComplete()
-        {
-            if (_steps != ESteps.Done)
-            {
-                YooLogger.Error($"Try load bundle {_bundle.BundleName} from remote : {_requestURL} !");
-            }
-        }
-
-        private void CreateWebRequest()
-        {
-            DownloadHandlerFile handler = new DownloadHandlerFile(_tempFilePath);
-            handler.removeFileOnAbort = true;
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadNormalFileOperation.cs.meta

@@ -1,11 +0,0 @@
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-guid: 759967d543776a0469b625eff171d235
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs

@@ -1,158 +0,0 @@
-using System.IO;
-using UnityEngine;
-using UnityEngine.Networking;
-
-namespace YooAsset
-{
-    internal sealed class UnityDownloadResumeFileOperation : UnityDownloadFileOperation
-    {
-        private VerifyTempFileOperation _verifyOperation;
-        private long _fileOriginLength = 0;
-        private ESteps _steps = ESteps.None;
-
-        internal UnityDownloadResumeFileOperation(DefaultCacheFileSystem fileSystem, PackageBundle bundle, string url)
-            : base(fileSystem, bundle, url)
-        {
-        }
-        internal override void InternalStart()
-        {
-            _steps = ESteps.CreateRequest;
-        }
-        internal override void InternalUpdate()
-        {
-            if (_steps == ESteps.None || _steps == ESteps.Done)
-                return;
-
-            // 创建下载器
-            if (_steps == ESteps.CreateRequest)
-            {
-                FileUtility.CreateFileDirectory(_tempFilePath);
-
-                // 获取下载起始位置
-                _fileOriginLength = 0;
-                long fileBeginLength = -1;
-                if (File.Exists(_tempFilePath))
-                {
-                    FileInfo fileInfo = new FileInfo(_tempFilePath);
-                    if (fileInfo.Length >= _bundle.FileSize)
-                    {
-                        File.Delete(_tempFilePath);
-                    }
-                    else
-                    {
-                        fileBeginLength = fileInfo.Length;
-                        _fileOriginLength = fileBeginLength;
-                        DownloadedBytes = _fileOriginLength;
-                    }
-                }
-
-                CreateWebRequest(fileBeginLength);
-                _steps = ESteps.Download;
-            }
-
-            // 检测下载结果
-            if (_steps == ESteps.Download)
-            {
-                DownloadProgress = _webRequest.downloadProgress;
-                DownloadedBytes = _fileOriginLength + (long)_webRequest.downloadedBytes;
-                Progress = DownloadProgress;
-
-                UpdateWatchDog();
-                if (_webRequest.isDone == false)
-                    return;
-
-                // 检查网络错误
-                if (CheckRequestResult())
-                {
-                    _steps = ESteps.VerifyFile;
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                }
-
-                // 在遇到特殊错误的时候删除文件
-                ClearTempFileWhenError();
-
-                // 注意：最终释放请求器
-                DisposeRequest();
-            }
-
-            // 验证下载文件
-            if (_steps == ESteps.VerifyFile)
-            {
-                if (_verifyOperation == null)
-                {
-                    var element = new TempFileElement(_tempFilePath, _bundle.FileCRC, _bundle.FileSize);
-                    _verifyOperation = new VerifyTempFileOperation(element);
-                    _verifyOperation.StartOperation();
-                    AddChildOperation(_verifyOperation);
-                }
-
-                if (IsWaitForAsyncComplete)
-                    _verifyOperation.WaitForAsyncComplete();
-
-                _verifyOperation.UpdateOperation();
-                if (_verifyOperation.IsDone == false)
-                    return;
-
-                if (_verifyOperation.Status == EOperationStatus.Succeed)
-                {
-                    if (_fileSystem.WriteCacheBundleFile(_bundle, _tempFilePath))
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Succeed;
-                    }
-                    else
-                    {
-                        _steps = ESteps.Done;
-                        Status = EOperationStatus.Failed;
-                        Error = $"{_fileSystem.GetType().FullName} failed to write file !";
-                    }
-                }
-                else
-                {
-                    _steps = ESteps.Done;
-                    Status = EOperationStatus.Failed;
-                    Error = _verifyOperation.Error;
-                }
-
-                // 注意：验证完成后直接删除文件
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-            }
-        }
-        internal override void InternalWaitForAsyncComplete()
-        {
-            if (_steps != ESteps.Done)
-            {
-                YooLogger.Error($"Try load bundle {_bundle.BundleName} from remote : {_requestURL} !");
-            }
-        }
-
-        private void ClearTempFileWhenError()
-        {
-            if (_fileSystem.ResumeDownloadResponseCodes == null)
-                return;
-
-            //说明：如果遇到以下错误返回码，验证失败直接删除文件
-            if (_fileSystem.ResumeDownloadResponseCodes.Contains(HttpCode))
-            {
-                if (File.Exists(_tempFilePath))
-                    File.Delete(_tempFilePath);
-            }
-        }
-        private void CreateWebRequest(long fileBeginLength)
-        {
-            var handler = new DownloadHandlerFile(_tempFilePath, true);
-            handler.removeFileOnAbort = false;
-            _webRequest = DownloadSystemHelper.NewUnityWebRequestGet(_requestURL);
-            _webRequest.downloadHandler = handler;
-            _webRequest.disposeDownloadHandlerOnDispose = true;
-            if (fileBeginLength > 0)
-                _webRequest.SetRequestHeader("Range", $"bytes={fileBeginLength}-");
-            _webRequest.SendWebRequest();
-        }
-    }
-}

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/UnityDownloadResumeFileOperation.cs.meta

@@ -1,11 +0,0 @@
-fileFormatVersion: 2
-guid: 9bfb785912326f942a31dc77762eb16a
-MonoImporter:
-  externalObjects: {}
-  serializedVersion: 2
-  defaultReferences: []
-  executionOrder: 0
-  icon: {instanceID: 0}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/Operation/internal/VerifyTempFileOperation.cs

@@ -76,7 +76,7 @@ namespace YooAsset
                 if (IsDone)
                     break;
 
-                // 短暂休眠避免完全卡死
+                //TODO 短暂休眠避免完全卡死
                 System.Threading.Thread.Sleep(1);
             }
         }

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/README.md

@@ -0,0 +1,791 @@
+# DefaultCacheFileSystem 缓存文件系统
+
+## 模块概述
+
+DefaultCacheFileSystem 是 YooAsset 的**缓存文件系统**，负责管理从远程服务器下载并缓存到本地沙盒的资源文件。该文件系统是联机运行模式（HostPlayMode）的核心组件，提供完整的下载、验证、缓存和加载功能。
+
+### 核心特性
+
+- **智能缓存管理**：基于 GUID 的文件索引，支持增量更新
+- **断点续传**：大文件下载支持从断点继续
+- **多线程验证**：后台线程验证文件完整性，不阻塞主线程
+- **并发下载**：可配置的下载并发数和请求速率
+- **覆盖安装检测**：App 版本变更时自动清理过期缓存
+- **加密支持**：支持加密资源包的解密加载
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **高性能** | 多线程验证、并发下载、路径缓存优化 |
+| **高可靠** | CRC/Hash 验证、损坏文件自动清理、加载失败重试 |
+| **可扩展** | 支持自定义解密服务、远程服务、本地拷贝服务 |
+| **易配置** | 丰富的参数配置，适应不同网络环境 |
+
+---
+
+## 文件结构
+
+```
+DefaultCacheFileSystem/
+├── DefaultCacheFileSystem.cs               # 文件系统主类
+├── DefaultCacheFileSystemDefine.cs         # 常量定义
+├── EOverwriteInstallClearMode.cs           # 覆盖安装清理模式枚举
+├── ApplicationFootPrint.cs                 # 应用版本足迹
+├── Elements/                               # 元素类
+│   ├── RecordFileElement.cs                # 缓存文件记录元素
+│   ├── TempFileElement.cs                  # 临时文件元素
+│   └── VerifyFileElement.cs                # 验证文件元素
+└── Operation/                              # 操作类
+    ├── DCFSInitializeOperation.cs          # 初始化操作
+    ├── DCFSRequestPackageVersionOperation.cs   # 请求版本操作
+    ├── DCFSLoadPackageManifestOperation.cs     # 加载清单操作
+    ├── DCFSLoadBundleOperation.cs          # 加载资源包操作
+    └── internal/                           # 内部操作类
+        ├── SearchCacheFilesOperation.cs        # 搜索缓存文件
+        ├── VerifyCacheFilesOperation.cs        # 验证缓存文件
+        ├── VerifyTempFileOperation.cs          # 验证临时文件
+        ├── DownloadPackageHashOperation.cs     # 下载哈希文件
+        ├── DownloadPackageManifestOperation.cs # 下载清单文件
+        ├── DownloadPackageBundleOperation.cs   # 下载资源包
+        ├── LoadCachePackageHashOperation.cs    # 加载缓存哈希
+        ├── LoadCachePackageManifestOperation.cs    # 加载缓存清单
+        ├── ClearAllCacheBundleFilesOperation.cs    # 清理所有缓存
+        ├── ClearUnusedCacheBundleFilesOperation.cs # 清理未使用缓存
+        ├── ClearCacheBundleFilesByTagsOperaiton.cs # 按标签清理
+        ├── ClearCacheBundleFilesByLocationsOperaiton.cs # 按位置清理
+        ├── ClearAllCacheManifestFilesOperation.cs  # 清理所有清单
+        ├── ClearUnusedCacheManifestFilesOperation.cs   # 清理未使用清单
+        └── Scheduler/                      # 下载调度器
+            ├── DownloadSchedulerOperation.cs       # 下载调度器
+            ├── DownloadAndCacheFileOperation.cs    # 下载并缓存基类
+            ├── DownloadAndCacheRemoteFileOperation.cs  # 远程文件下载
+            └── DownloadAndCacheLocalFileOperation.cs   # 本地文件拷贝
+```
+
+---
+
+## 核心类说明
+
+### DefaultCacheFileSystem
+
+缓存文件系统的主类，实现 `IFileSystem` 接口。
+
+#### 基本属性
+
+| 属性 | 类型 | 说明 |
+|------|------|------|
+| `PackageName` | `string` | 包裹名称 |
+| `FileRoot` | `string` | 缓存根目录 |
+| `FileCount` | `int` | 已缓存文件数量 |
+| `DownloadBackend` | `IDownloadBackend` | 下载后台接口 |
+| `DownloadScheduler` | `DownloadSchedulerOperation` | 下载调度器 |
+
+#### 自定义参数
+
+| 参数 | 类型 | 默认值 | 说明 |
+|------|------|--------|------|
+| `RemoteServices` | `IRemoteServices` | - | 远程服务接口（必需） |
+| `InstallClearMode` | `EOverwriteInstallClearMode` | `ClearAllManifestFiles` | 覆盖安装缓存清理模式 |
+| `FileVerifyLevel` | `EFileVerifyLevel` | `Middle` | 初始化时文件校验级别 |
+| `FileVerifyMaxConcurrency` | `int` | `32` | 文件校验最大并发数（1-256） |
+| `AppendFileExtension` | `bool` | `false` | 数据文件追加文件扩展名 |
+| `DisableOnDemandDownload` | `bool` | `false` | 禁用边玩边下机制 |
+| `DownloadMaxConcurrency` | `int` | `10` | 最大并发下载数（1-64） |
+| `DownloadMaxRequestPerFrame` | `int` | `5` | 每帧最大请求数（1-20） |
+| `DownloadWatchDogTime` | `int` | `0` | 下载看门狗超时时间（秒） |
+| `ResumeDownloadMinimumSize` | `long` | `long.MaxValue` | 启用断点续传的最小文件大小 |
+| `ResumeDownloadResponseCodes` | `List<long>` | `null` | 断点续传关注的HTTP错误码 |
+| `DecryptionServices` | `IDecryptionServices` | `null` | 解密服务接口 |
+| `ManifestServices` | `IManifestRestoreServices` | `null` | 清单服务接口 |
+| `CopyLocalFileServices` | `ICopyLocalFileServices` | `null` | 本地文件拷贝服务 |
+
+#### 核心方法
+
+```csharp
+// 生命周期
+void OnCreate(string packageName, string packageRoot);
+void OnDestroy();
+void SetParameter(string name, object value);
+
+// 异步操作
+FSInitializeFileSystemOperation InitializeFileSystemAsync();
+FSRequestPackageVersionOperation RequestPackageVersionAsync(bool appendTimeTicks, int timeout);
+FSLoadPackageManifestOperation LoadPackageManifestAsync(string packageVersion, int timeout);
+FSLoadBundleOperation LoadBundleFile(PackageBundle bundle);
+FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options);
+FSClearCacheFilesOperation ClearCacheFilesAsync(PackageManifest manifest, ClearCacheFilesOptions options);
+
+// 文件查询
+bool Belong(PackageBundle bundle);       // 始终返回 true（保底加载）
+bool Exists(PackageBundle bundle);       // 检查文件是否已缓存
+bool NeedDownload(PackageBundle bundle); // 检查是否需要下载
+bool NeedUnpack(PackageBundle bundle);   // 始终返回 false
+bool NeedImport(PackageBundle bundle);   // 检查是否需要导入
+
+// 文件访问
+string GetBundleFilePath(PackageBundle bundle);
+byte[] ReadBundleFileData(PackageBundle bundle);
+string ReadBundleFileText(PackageBundle bundle);
+```
+
+---
+
+## 缓存目录结构
+
+```
+{CacheRoot}/{PackageName}/
+├── BundleFiles/                           # 资源包文件目录
+│   ├── {Hash[0:2]}/                       # 哈希前两位分组（256个目录）
+│   │   ├── {BundleGUID}/                  # 资源包 GUID 目录
+│   │   │   ├── __data                     # 数据文件（或 __data.bundle）
+│   │   │   └── __info                     # 信息文件（CRC + Size）
+│   │   └── ...
+│   └── ...
+├── ManifestFiles/                         # 清单文件目录
+│   ├── {PackageName}_{Version}.bytes      # 清单二进制文件
+│   ├── {PackageName}_{Version}.hash       # 清单哈希文件
+│   └── __app_footprint.txt                # 应用版本足迹文件
+└── TempFiles/                             # 临时文件目录
+    ├── {BundleGUID}                       # 下载中的临时文件
+    └── ...
+```
+
+### 信息文件格式（__info）
+
+```
+| 字段 | 类型 | 大小 | 说明 |
+|------|------|------|------|
+| DataFileCRC | uint32 | 4 bytes | 数据文件 CRC |
+| DataFileSize | int64 | 8 bytes | 数据文件大小 |
+```
+
+---
+
+## 操作类说明
+
+### DCFSInitializeOperation
+
+初始化操作，执行完整的缓存系统初始化流程。
+
+```
+状态流程：
+CheckAppFootPrint
+    ├── 版本相同 → 继续
+    └── 版本不同 → 根据 InstallClearMode 清理缓存
+            ↓
+SearchCacheFiles
+    └── SearchCacheFilesOperation
+            └── 遍历 BundleFiles 目录
+                    └── 收集需要验证的文件
+                            ↓
+VerifyCacheFiles
+    └── VerifyCacheFilesOperation（多线程）
+            ├── 验证成功 → 记录到 _records
+            └── 验证失败 → 删除损坏文件
+                    ↓
+CreateDownloadScheduler
+    └── 创建 DownloadSchedulerOperation
+            ↓
+Done → Status = Succeed
+```
+
+#### 状态机枚举
+
+```csharp
+private enum ESteps
+{
+    None,
+    CheckAppFootPrint,      // 检查应用版本足迹
+    SearchCacheFiles,       // 搜索缓存文件
+    VerifyCacheFiles,       // 验证缓存文件
+    CreateDownloadScheduler,// 创建下载调度器
+    Done                    // 完成
+}
+```
+
+### DCFSLoadAssetBundleOperation
+
+加载 AssetBundle 操作，支持按需下载和多重容错机制。
+
+```
+状态流程：
+CheckExist
+    ├── 已缓存 → LoadAssetBundle
+    └── 未缓存 → 检查 DisableOnDemandDownload
+            ├── 禁用 → Failed
+            └── 启用 → DownloadFile
+                        ↓
+DownloadFile
+    └── DownloadFileAsync()
+            ├── 下载成功 → LoadAssetBundle
+            └── 下载失败 → Failed
+                        ↓
+LoadAssetBundle
+    ├── 未加密 → AssetBundle.LoadFromFile[Async]
+    └── 已加密 → DecryptionServices.LoadAssetBundle[Async]
+                        ↓
+CheckResult
+    ├── 加载成功 → AssetBundleResult → Succeed
+    └── 加载失败 → 验证文件完整性
+            ├── 验证通过 → LoadFromMemory 重试
+            └── 验证失败 → 删除损坏文件 → Failed
+```
+
+#### 移动平台容错机制
+
+```csharp
+// 注意：在安卓移动平台，华为和三星真机上有极小概率加载资源包失败。
+// 说明：大多数情况在首次安装下载资源到沙盒内，游戏过程中切换到后台再回到游戏内有很大概率触发！
+string filePath = _fileSystem.GetCacheBundleFileLoadPath(_bundle);
+byte[] fileData = FileUtility.ReadAllBytes(filePath);
+if (fileData != null && fileData.Length > 0)
+{
+    _assetBundle = AssetBundle.LoadFromMemory(fileData);
+    // ...
+}
+```
+
+### DCFSLoadRawBundleOperation
+
+加载原生资源包操作，处理文件格式变更场景。
+
+```csharp
+// 注意：缓存的原生文件的格式，可能会在业务端根据需求发生变动！
+// 注意：这里需要校验文件格式，如果不一致对本地文件进行修正！
+if (File.Exists(filePath) == false)
+{
+    var recordFileElement = _fileSystem.GetRecordFileElement(_bundle);
+    File.Move(recordFileElement.DataFilePath, filePath);
+}
+```
+
+---
+
+## 下载调度器
+
+### DownloadSchedulerOperation
+
+管理所有活跃的下载任务，控制并发数量。
+
+#### 核心属性
+
+| 属性 | 类型 | 说明 |
+|------|------|------|
+| `Paused` | `bool` | 是否已暂停 |
+| `ActiveDownloadCount` | `int` | 当前活跃的下载任务数 |
+| `PendingDownloadCount` | `int` | 当前等待中的下载任务数 |
+
+#### 工作原理
+
+```
+InternalUpdate()
+    │
+    ├── 1. 驱动下载后台 _fileSystem.DownloadBackend.Update()
+    │
+    ├── 2. 遍历下载器集合
+    │       ├── 已完成 → 加入移除列表
+    │       └── RefCount <= 0 → 中止并移除
+    │
+    ├── 3. 移除已完成/中止的下载器
+    │
+    └── 4. 启动新下载任务（如未暂停）
+            ├── 计算可启动数量 = min(maxConcurrency - active, maxRequestPerFrame)
+            └── 启动等待中的下载器
+```
+
+#### 引用计数机制
+
+```csharp
+// 查询旧的下载器（复用）
+if (_downloaders.TryGetValue(bundle.BundleGUID, out var oldDownloader))
+{
+    oldDownloader.Reference();  // 引用计数 +1
+    return oldDownloader;
+}
+
+// 创建新的下载器
+DownloadAndCacheFileOperation newDownloader;
+// ...
+newDownloader.Reference();  // 引用计数 +1
+```
+
+### DownloadAndCacheRemoteFileOperation
+
+远程文件下载操作，支持断点续传。
+
+```
+状态流程：
+CreateRequest
+    ├── 文件大小 >= ResumeDownloadMinimumSize
+    │       └── CreateResumeRequest（断点续传）
+    └── 文件大小 < ResumeDownloadMinimumSize
+            └── CreateNormalRequest（普通下载）
+                    ↓
+CheckRequest
+    ├── 下载成功 → VerifyBundleFile
+    └── 下载失败 → ClearTempFileWhenError → Failed
+                    ↓
+VerifyBundleFile
+    └── VerifyTempFileOperation（多线程验证）
+            ├── 验证成功 → CacheBundleFile
+            └── 验证失败 → 删除临时文件 → Failed
+                    ↓
+CacheBundleFile
+    └── WriteCacheBundleFile()
+            ├── 成功 → 删除临时文件 → Succeed
+            └── 失败 → Failed
+```
+
+#### 断点续传实现
+
+```csharp
+private IDownloadRequest CreateResumeRequest()
+{
+    // 获取下载起始位置
+    if (File.Exists(_tempFilePath))
+    {
+        FileInfo fileInfo = new FileInfo(_tempFilePath);
+        if (fileInfo.Length >= _bundle.FileSize)
+        {
+            File.Delete(_tempFilePath);  // 文件已完整，删除重下
+        }
+        else
+        {
+            _fileOriginLength = fileInfo.Length;  // 记录已下载大小
+        }
+    }
+
+    var args = new DownloadFileRequestArgs(
+        URL, _tempFilePath, timeout, watchdogTime,
+        appendToFile: true,          // 追加写入
+        removeFileOnAbort: false,    // 中止时保留文件
+        resumeFromBytes: _fileOriginLength  // 断点位置
+    );
+    return _fileSystem.DownloadBackend.CreateFileRequest(args);
+}
+```
+
+---
+
+## 缓存验证系统
+
+### VerifyCacheFilesOperation
+
+多线程缓存文件验证，在初始化时执行。
+
+#### 验证流程
+
+```
+InitVerify
+    ├── 获取系统线程池信息
+    └── 计算实际并发数 = min(threads, FileVerifyMaxConcurrency)
+            ↓
+UpdateVerify（循环）
+    ├── 检测已完成的验证任务
+    │       ├── 验证成功 → RecordBundleFile
+    │       └── 验证失败 → DeleteFiles
+    │
+    └── 启动新的验证任务
+            └── ThreadPool.QueueUserWorkItem(VerifyInThread)
+```
+
+#### 验证级别
+
+```csharp
+private EFileVerifyResult VerifyingCacheFile(VerifyFileElement element, EFileVerifyLevel verifyLevel)
+{
+    if (verifyLevel == EFileVerifyLevel.Low)
+    {
+        // Low：仅检查文件存在
+        if (File.Exists(element.InfoFilePath) == false)
+            return EFileVerifyResult.InfoFileNotExisted;
+        if (File.Exists(element.DataFilePath) == false)
+            return EFileVerifyResult.DataFileNotExisted;
+        return EFileVerifyResult.Succeed;
+    }
+    else
+    {
+        // Middle/High：检查文件存在 + CRC/Size 验证
+        _fileSystem.ReadBundleInfoFile(element.InfoFilePath, out element.DataFileCRC, out element.DataFileSize);
+        return FileVerifyHelper.FileVerify(element.DataFilePath, element.DataFileSize, element.DataFileCRC, verifyLevel);
+    }
+}
+```
+
+### VerifyTempFileOperation
+
+下载文件验证，在线程池中执行。
+
+```csharp
+private void VerifyInThread(object obj)
+{
+    TempFileElement element = (TempFileElement)obj;
+    int result = (int)FileVerifyHelper.FileVerify(
+        element.TempFilePath,
+        element.TempFileSize,
+        element.TempFileCRC,
+        EFileVerifyLevel.High  // 始终使用高级验证
+    );
+    element.Result = result;  // 线程安全的结果设置
+}
+```
+
+---
+
+## 覆盖安装检测
+
+### ApplicationFootPrint
+
+应用版本足迹，用于检测 App 覆盖安装。
+
+```csharp
+public static bool IsDirty(DefaultCacheFileSystem fileSystem)
+{
+    string filePath = fileSystem.GetSandboxAppFootPrintFilePath();
+    if (File.Exists(filePath))
+    {
+        string footPrint = FileUtility.ReadAllText(filePath);
+        return IsValidVersion(footPrint) == false;  // 版本不同
+    }
+    return true;  // 文件不存在
+}
+```
+
+### EOverwriteInstallClearMode
+
+覆盖安装时的缓存清理模式。
+
+| 枚举值 | 说明 |
+|--------|------|
+| `NeverClear` | 不清理任何缓存 |
+| `ClearAllManifestFiles` | 清理所有清单文件（默认） |
+| `ClearAllBundleAndManifestFiles` | 清理所有资源包和清单文件 |
+
+---
+
+## 缓存清理操作
+
+### 清理模式对照表
+
+| 清理模式 | 操作类 | 说明 |
+|----------|--------|------|
+| `ClearAllBundleFiles` | `ClearAllCacheBundleFilesOperation` | 清理所有缓存资源包 |
+| `ClearUnusedBundleFiles` | `ClearUnusedCacheBundleFilesOperation` | 清理不在清单中的资源包 |
+| `ClearBundleFilesByTags` | `ClearCacheBundleFilesByTagsOperaiton` | 按标签清理 |
+| `ClearBundleFilesByLocations` | `ClearCacheBundleFilesByLocationsOperaiton` | 按资源路径清理 |
+| `ClearAllManifestFiles` | `ClearAllCacheManifestFilesOperation` | 清理所有清单文件 |
+| `ClearUnusedManifestFiles` | `ClearUnusedCacheManifestFilesOperation` | 清理未使用的清单文件 |
+
+### 时间切片清理
+
+```csharp
+for (int i = _allBundleGUIDs.Count - 1; i >= 0; i--)
+{
+    string bundleGUID = _allBundleGUIDs[i];
+    _fileSystem.DeleteCacheBundleFile(bundleGUID);
+    _allBundleGUIDs.RemoveAt(i);
+
+    // 检查操作系统是否繁忙，避免阻塞主线程
+    if (OperationSystem.IsBusy)
+        break;
+}
+```
+
+---
+
+## 元素类说明
+
+### RecordFileElement
+
+缓存文件记录元素，存储已验证的缓存文件信息。
+
+```csharp
+internal class RecordFileElement
+{
+    public readonly string InfoFilePath;   // 信息文件路径
+    public readonly string DataFilePath;   // 数据文件路径
+    public readonly uint DataFileCRC;      // 数据文件 CRC
+    public readonly long DataFileSize;     // 数据文件大小
+
+    public bool DeleteFolder();            // 删除整个文件夹
+}
+```
+
+### TempFileElement
+
+临时文件元素，用于下载文件验证。
+
+```csharp
+internal class TempFileElement
+{
+    public readonly string TempFilePath;   // 临时文件路径
+    public readonly uint TempFileCRC;      // 预期 CRC
+    public readonly long TempFileSize;     // 预期文件大小
+
+    private int _result = 0;
+    public int Result                      // 线程安全的验证结果
+    {
+        get => Interlocked.CompareExchange(ref _result, 0, 0);
+        set => Interlocked.Exchange(ref _result, value);
+    }
+}
+```
+
+### VerifyFileElement
+
+验证文件元素，用于缓存文件批量验证。
+
+```csharp
+internal class VerifyFileElement
+{
+    public readonly string PackageName;    // 包裹名称
+    public readonly string BundleGUID;     // 资源包 GUID
+    public readonly string FileRootPath;   // 文件根目录
+    public readonly string DataFilePath;   // 数据文件路径
+    public readonly string InfoFilePath;   // 信息文件路径
+
+    public uint DataFileCRC;               // 数据文件 CRC
+    public long DataFileSize;              // 数据文件大小
+
+    private int _result = 0;
+    public int Result                      // 线程安全的验证结果
+    {
+        get => Interlocked.CompareExchange(ref _result, 0, 0);
+        set => Interlocked.Exchange(ref _result, value);
+    }
+
+    public void DeleteFiles();             // 删除所有相关文件
+}
+```
+
+---
+
+## 使用示例
+
+### 基础配置
+
+```csharp
+// 创建远程服务接口
+class GameRemoteServices : IRemoteServices
+{
+    public string GetRemoteMainURL(string fileName)
+    {
+        return $"https://cdn.example.com/bundles/{fileName}";
+    }
+    public string GetRemoteFallbackURL(string fileName)
+    {
+        return $"https://cdn-backup.example.com/bundles/{fileName}";
+    }
+}
+
+// 创建缓存文件系统参数
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 初始化包裹
+var initParams = new HostPlayModeParameters();
+initParams.BuildinFileSystemParameters = buildinParams;
+initParams.CacheFileSystemParameters = cacheParams;
+var initOp = package.InitializeAsync(initParams);
+```
+
+### 配置下载参数
+
+```csharp
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 设置下载并发数
+cacheParams.AddParameter(FileSystemParametersDefine.DOWNLOAD_MAX_CONCURRENCY, 8);
+
+// 设置每帧最大请求数
+cacheParams.AddParameter(FileSystemParametersDefine.DOWNLOAD_MAX_REQUEST_PER_FRAME, 3);
+
+// 设置下载看门狗时间（秒）
+cacheParams.AddParameter(FileSystemParametersDefine.DOWNLOAD_WATCH_DOG_TIME, 30);
+```
+
+### 配置断点续传
+
+```csharp
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 启用断点续传的最小文件大小（1MB）
+cacheParams.AddParameter(FileSystemParametersDefine.RESUME_DOWNLOAD_MINMUM_SIZE, 1024 * 1024);
+
+// 断点续传关注的HTTP错误码（这些错误码时删除临时文件重新下载）
+var responseCodes = new List<long> { 416 };  // Range Not Satisfiable
+cacheParams.AddParameter(FileSystemParametersDefine.RESUME_DOWNLOAD_RESPONSE_CODES, responseCodes);
+```
+
+### 配置文件验证
+
+```csharp
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 设置验证级别
+cacheParams.AddParameter(FileSystemParametersDefine.FILE_VERIFY_LEVEL, EFileVerifyLevel.High);
+
+// 设置验证并发数
+cacheParams.AddParameter(FileSystemParametersDefine.FILE_VERIFY_MAX_CONCURRENCY, 64);
+```
+
+### 配置加密支持
+
+```csharp
+// 自定义解密服务
+class GameDecryptionServices : IDecryptionServices
+{
+    public DecryptResult LoadAssetBundle(DecryptFileInfo fileInfo)
+    {
+        // 实现解密逻辑
+        byte[] data = DecryptFile(fileInfo.FileLoadPath);
+        AssetBundle bundle = AssetBundle.LoadFromMemory(data);
+        return new DecryptResult { Result = bundle };
+    }
+    // ...
+}
+
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 设置解密服务
+cacheParams.AddParameter(FileSystemParametersDefine.DECRYPTION_SERVICES, new GameDecryptionServices());
+```
+
+### 配置覆盖安装行为
+
+```csharp
+var cacheParams = FileSystemParameters.CreateDefaultCacheFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 覆盖安装时清理所有资源包和清单
+cacheParams.AddParameter(
+    FileSystemParametersDefine.INSTALL_CLEAR_MODE,
+    EOverwriteInstallClearMode.ClearAllBundleAndManifestFiles
+);
+```
+
+### 清理缓存
+
+```csharp
+// 清理所有缓存
+var clearOp = package.ClearCacheFilesAsync(EFileClearMode.ClearAllBundleFiles);
+await clearOp.ToTask();
+
+// 清理未使用的缓存
+var clearOp = package.ClearCacheFilesAsync(EFileClearMode.ClearUnusedBundleFiles);
+await clearOp.ToTask();
+
+// 按标签清理
+var clearOp = package.ClearCacheFilesAsync(EFileClearMode.ClearBundleFilesByTags, "dlc1");
+await clearOp.ToTask();
+```
+
+---
+
+## 参数常量
+
+```csharp
+// 远程服务
+FileSystemParametersDefine.REMOTE_SERVICES           // IRemoteServices: 远程服务接口
+
+// 覆盖安装
+FileSystemParametersDefine.INSTALL_CLEAR_MODE        // EOverwriteInstallClearMode: 清理模式
+
+// 文件验证
+FileSystemParametersDefine.FILE_VERIFY_LEVEL         // EFileVerifyLevel: 验证级别
+FileSystemParametersDefine.FILE_VERIFY_MAX_CONCURRENCY  // int: 验证并发数
+
+// 文件格式
+FileSystemParametersDefine.APPEND_FILE_EXTENSION     // bool: 追加文件扩展名
+
+// 下载控制
+FileSystemParametersDefine.DISABLE_ONDEMAND_DOWNLOAD // bool: 禁用边玩边下
+FileSystemParametersDefine.DOWNLOAD_MAX_CONCURRENCY  // int: 下载并发数
+FileSystemParametersDefine.DOWNLOAD_MAX_REQUEST_PER_FRAME  // int: 每帧请求数
+FileSystemParametersDefine.DOWNLOAD_WATCH_DOG_TIME   // int: 看门狗时间
+
+// 断点续传
+FileSystemParametersDefine.RESUME_DOWNLOAD_MINMUM_SIZE     // long: 最小文件大小
+FileSystemParametersDefine.RESUME_DOWNLOAD_RESPONSE_CODES  // List<long>: 关注错误码
+
+// 服务接口
+FileSystemParametersDefine.DECRYPTION_SERVICES       // IDecryptionServices: 解密服务
+FileSystemParametersDefine.MANIFEST_SERVICES         // IManifestRestoreServices: 清单服务
+FileSystemParametersDefine.COPY_LOCAL_FILE_SERVICES  // ICopyLocalFileServices: 本地拷贝服务
+```
+
+---
+
+## 类继承关系
+
+```
+IFileSystem
+    └── DefaultCacheFileSystem
+
+FSInitializeFileSystemOperation
+    └── DCFSInitializeOperation
+
+FSRequestPackageVersionOperation
+    └── DCFSRequestPackageVersionOperation
+
+FSLoadPackageManifestOperation
+    └── DCFSLoadPackageManifestOperation
+
+FSLoadBundleOperation
+    ├── DCFSLoadAssetBundleOperation
+    └── DCFSLoadRawBundleOperation
+
+FSDownloadFileOperation
+    └── DownloadPackageBundleOperation
+
+FSClearCacheFilesOperation
+    ├── ClearAllCacheBundleFilesOperation
+    ├── ClearUnusedCacheBundleFilesOperation
+    ├── ClearCacheBundleFilesByTagsOperaiton
+    ├── ClearCacheBundleFilesByLocationsOperaiton
+    ├── ClearAllCacheManifestFilesOperation
+    └── ClearUnusedCacheManifestFilesOperation
+
+AsyncOperationBase
+    ├── DownloadSchedulerOperation
+    ├── DownloadAndCacheFileOperation (abstract)
+    │   ├── DownloadAndCacheRemoteFileOperation
+    │   └── DownloadAndCacheLocalFileOperation
+    ├── SearchCacheFilesOperation
+    ├── VerifyCacheFilesOperation
+    ├── VerifyTempFileOperation
+    ├── DownloadPackageHashOperation
+    ├── DownloadPackageManifestOperation
+    ├── LoadCachePackageHashOperation
+    ├── LoadCachePackageManifestOperation
+    └── RequestRemotePackageVersionOperation
+
+BundleResult
+    ├── AssetBundleResult  ← AssetBundle 资源
+    └── RawBundleResult    ← 原生文件资源
+```
+
+---
+
+## 注意事项
+
+1. **远程服务必需**：使用缓存文件系统必须配置 `IRemoteServices` 接口
+2. **保底加载**：缓存文件系统的 `Belong()` 始终返回 true，作为资源加载的保底方案
+3. **线程安全**：文件验证和下载使用后台线程，但核心逻辑仍在主线程执行
+4. **并发限制**：合理设置下载和验证的并发数，避免系统过载
+5. **移动平台**：Android 平台存在极小概率的 AssetBundle 加载失败，系统会自动尝试 LoadFromMemory 作为备选方案
+6. **断点续传**：启用断点续传时，需要合理设置 `ResumeDownloadMinimumSize` 和 `ResumeDownloadResponseCodes`
+7. **覆盖安装**：App 版本更新时会自动检测并根据配置清理缓存，避免旧缓存导致问题

Assets/YooAsset/Runtime/FileSystem/DefaultCacheFileSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 8292f707fbf60854e852e1a75824d892
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultEditorFileSystem/DefaultEditorFileSystem.cs

@@ -11,6 +11,11 @@ namespace YooAsset
         protected readonly Dictionary<string, string> _records = new Dictionary<string, string>(10000);
         protected string _packageRoot;
 
+        /// <summary>
+        /// 下载后台接口
+        /// </summary>
+        public IDownloadBackend DownloadBackend { private set; get; }
+
         /// <summary>
         /// 包裹名称
         /// </summary>
@@ -39,6 +44,11 @@ namespace YooAsset
         }
 
         #region 自定义参数
+        /// <summary>
+        /// 自定义参数：UnityWebRequest 创建委托
+        /// </summary>
+        public UnityWebRequestCreator WebRequestCreator { private set; get; }
+
         /// <summary>
         /// 模拟WebGL平台模式
         /// </summary>
@@ -112,7 +122,15 @@ namespace YooAsset
 
         public virtual void SetParameter(string name, object value)
         {
-            if (name == FileSystemParametersDefine.VIRTUAL_WEBGL_MODE)
+            if (name == FileSystemParametersDefine.DOWNLOAD_BACKEND)
+            {
+                DownloadBackend = (IDownloadBackend)value;
+            }
+            else if (name == FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR)
+            {
+                WebRequestCreator = (UnityWebRequestCreator)value;
+            }
+            else if (name == FileSystemParametersDefine.VIRTUAL_WEBGL_MODE)
             {
                 VirtualWebGLMode = Convert.ToBoolean(value);
             }
@@ -142,12 +160,21 @@ namespace YooAsset
             PackageName = packageName;
 
             if (string.IsNullOrEmpty(packageRoot))
-                throw new Exception($"{nameof(DefaultEditorFileSystem)} root directory is null or empty !");
+                throw new YooFileSystemException($"{nameof(DefaultEditorFileSystem)} package root is null or empty !");
 
             _packageRoot = packageRoot;
+
+            // 创建默认的下载后台接口
+            if (DownloadBackend == null)
+                DownloadBackend = new UnityWebRequestBackend(WebRequestCreator);
         }
         public virtual void OnDestroy()
         {
+            if (DownloadBackend != null)
+            {
+                DownloadBackend.Dispose();
+                DownloadBackend = null;
+            }
         }
 
         public virtual bool Belong(PackageBundle bundle)

Assets/YooAsset/Runtime/FileSystem/DefaultEditorFileSystem/Operation/internal/DownloadVirutalBundleOperation.cs

@@ -17,7 +17,7 @@ namespace YooAsset
         // 下载参数
         protected readonly DefaultEditorFileSystem _fileSystem;
         protected readonly DownloadFileOptions _options;
-        protected UnityVirtualBundleRequestOperation _unityDownloadFileOp;
+        protected IDownloadFileRequest _downloadFileOp;
 
         protected int _requestCount = 0;
         protected float _tryAgainTimer = 0;
@@ -68,29 +68,22 @@ namespace YooAsset
 
                 string url = GetRequestURL();
                 int speed = _fileSystem.VirtualDownloadSpeed;
-                _unityDownloadFileOp = new UnityVirtualBundleRequestOperation(Bundle, speed, url);
+                var args = new DownloadSimulateRequestArgs(url, Bundle.FileSize, speed);
-                _unityDownloadFileOp.StartOperation();
+                _downloadFileOp = _fileSystem.DownloadBackend.CreateSimulateRequest(args);
+                _downloadFileOp.SendRequest();
                 _steps = ESteps.CheckRequest;
             }
 
             // 检测下载结果
             if (_steps == ESteps.CheckRequest)
             {
-                if (IsWaitForAsyncComplete)
+                Progress = _downloadFileOp.DownloadProgress;
-                    _unityDownloadFileOp.WaitForAsyncComplete();
+                DownloadedBytes = _downloadFileOp.DownloadedBytes;
-
+                DownloadProgress = _downloadFileOp.DownloadProgress;
-                // 因为并发数量限制，下载器可能被挂起！
+                if (_downloadFileOp.IsDone == false)
-                if (_unityDownloadFileOp.Status == EOperationStatus.None)
                     return;
 
-                _unityDownloadFileOp.UpdateOperation();
+                if (_downloadFileOp.Status == EDownloadRequestStatus.Succeed)
-                Progress = _unityDownloadFileOp.Progress;
-                DownloadedBytes = _unityDownloadFileOp.DownloadedBytes;
-                DownloadProgress = _unityDownloadFileOp.DownloadProgress;
-                if (_unityDownloadFileOp.IsDone == false)
-                    return;
-
-                if (_unityDownloadFileOp.Status == EOperationStatus.Succeed)
                 {
                     _fileSystem.RecordDownloadFile(Bundle);
                     _steps = ESteps.Done;
@@ -101,13 +94,13 @@ namespace YooAsset
                     if (IsWaitForAsyncComplete == false && _failedTryAgain > 0)
                     {
                         _steps = ESteps.TryAgain;
-                        YooLogger.Warning($"Failed download : {_unityDownloadFileOp.URL} Try again !");
+                        YooLogger.Warning($"Failed download : {_downloadFileOp.URL} Try again !");
                     }
                     else
                     {
                         _steps = ESteps.Done;
                         Status = EOperationStatus.Failed;
-                        Error = _unityDownloadFileOp.Error;
+                        Error = _downloadFileOp.Error;
                         YooLogger.Error(Error);
                     }
                 }
@@ -130,13 +123,12 @@ namespace YooAsset
         }
         internal override void InternalWaitForAsyncComplete()
         {
-            while (true)
+            if (_steps != ESteps.Done)
-            {
-                if (ExecuteWhileDone())
             {
                 _steps = ESteps.Done;
-                    break;
+                Status = EOperationStatus.Failed;
-                }
+                Error = $"Try load bundle {Bundle.BundleName} from remote !";
+                YooLogger.Error(Error);
             }
         }
 

Assets/YooAsset/Runtime/FileSystem/DefaultEditorFileSystem/README.md

@@ -0,0 +1,424 @@
+# DefaultEditorFileSystem 编辑器模拟文件系统
+
+## 模块概述
+
+DefaultEditorFileSystem 是 YooAsset 的**编辑器模拟文件系统**，专为 Unity 编辑器开发环境设计。该文件系统无需构建实际的 AssetBundle 文件，直接使用 Unity 的 AssetDatabase API 加载资源，实现快速迭代开发。
+
+### 核心特性
+
+- **无需构建资源包**：直接使用 AssetDatabase 加载资源
+- **模拟下载流程**：支持模拟网络下载行为（用于 UI 调试）
+- **模拟异步延迟**：可配置异步加载的模拟帧数
+- **WebGL 模式模拟**：支持模拟 WebGL 平台行为
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **快速迭代** | 无需构建 AssetBundle，修改资源后立即生效 |
+| **行为模拟** | 模拟真实环境的下载和加载行为 |
+| **调试友好** | 支持 UI 进度条等功能的调试 |
+| **零配置** | 开箱即用，最小化配置需求 |
+
+---
+
+## 文件结构
+
+```
+DefaultEditorFileSystem/
+├── DefaultEditorFileSystem.cs           # 文件系统主类
+├── DefaultEditorFileSystemDefine.cs     # 常量定义（预留）
+└── Operation/                           # 操作类
+    ├── DEFSInitializeOperation.cs       # 初始化操作
+    ├── DEFSRequestPackageVersionOperation.cs  # 请求版本操作
+    ├── DEFSLoadPackageManifestOperation.cs    # 加载清单操作
+    ├── DEFSLoadBundleOperation.cs       # 加载资源包操作
+    └── internal/                        # 内部操作类
+        ├── DownloadVirutalBundleOperation.cs      # 虚拟下载操作
+        ├── LoadEditorPackageVersionOperation.cs   # 加载版本文件操作
+        ├── LoadEditorPackageHashOperation.cs      # 加载哈希文件操作
+        └── LoadEditorPackageManifestOperation.cs  # 加载清单文件操作
+```
+
+---
+
+## 核心类说明
+
+### DefaultEditorFileSystem
+
+编辑器模拟文件系统的主类，实现 `IFileSystem` 接口。
+
+#### 基本属性
+
+| 属性 | 类型 | 说明 |
+|------|------|------|
+| `PackageName` | `string` | 包裹名称 |
+| `FileRoot` | `string` | 文件根目录（清单文件所在目录） |
+| `FileCount` | `int` | 文件数量（始终返回 0） |
+| `DownloadBackend` | `IDownloadBackend` | 下载后台接口 |
+
+#### 自定义参数
+
+| 参数 | 类型 | 默认值 | 说明 |
+|------|------|--------|------|
+| `VirtualWebGLMode` | `bool` | `false` | 模拟 WebGL 平台模式 |
+| `VirtualDownloadMode` | `bool` | `false` | 模拟虚拟下载模式 |
+| `VirtualDownloadSpeed` | `int` | `1024` | 模拟下载速度（字节/秒） |
+| `AsyncSimulateMinFrame` | `int` | `1` | 异步加载最小模拟帧数 |
+| `AsyncSimulateMaxFrame` | `int` | `1` | 异步加载最大模拟帧数 |
+
+#### 核心方法
+
+```csharp
+// 生命周期
+void OnCreate(string packageName, string packageRoot);
+void OnDestroy();
+void SetParameter(string name, object value);
+
+// 异步操作
+FSInitializeFileSystemOperation InitializeFileSystemAsync();
+FSRequestPackageVersionOperation RequestPackageVersionAsync(bool appendTimeTicks, int timeout);
+FSLoadPackageManifestOperation LoadPackageManifestAsync(string packageVersion, int timeout);
+FSLoadBundleOperation LoadBundleFile(PackageBundle bundle);
+FSDownloadFileOperation DownloadFileAsync(PackageBundle bundle, DownloadFileOptions options);
+FSClearCacheFilesOperation ClearCacheFilesAsync(PackageManifest manifest, ClearCacheFilesOptions options);
+
+// 文件查询
+bool Belong(PackageBundle bundle);      // 始终返回 true
+bool Exists(PackageBundle bundle);      // VirtualDownloadMode 时检查记录
+bool NeedDownload(PackageBundle bundle);// VirtualDownloadMode 时返回未记录的文件
+bool NeedUnpack(PackageBundle bundle);  // 始终返回 false
+bool NeedImport(PackageBundle bundle);  // 始终返回 false
+
+// 文件访问
+string GetBundleFilePath(PackageBundle bundle);   // 返回资源路径
+byte[] ReadBundleFileData(PackageBundle bundle);  // 读取文件二进制
+string ReadBundleFileText(PackageBundle bundle);  // 读取文件文本
+```
+
+---
+
+## 操作类说明
+
+### DEFSInitializeOperation
+
+初始化操作，立即完成（无需任何初始化工作）。
+
+```
+状态流程：InternalStart() → Status = Succeed
+```
+
+### DEFSRequestPackageVersionOperation
+
+请求包裹版本操作，从本地版本文件读取版本号。
+
+```
+状态流程：
+LoadPackageVersion
+    └── LoadEditorPackageVersionOperation
+            └── 读取 {PackageName}_Version.txt
+                    ├── 成功 → PackageVersion = 文件内容
+                    └── 失败 → Error
+```
+
+### DEFSLoadPackageManifestOperation
+
+加载资源清单操作，从本地清单文件加载并解析清单。
+
+```
+状态流程：
+LoadEditorPackageHash
+    └── LoadEditorPackageHashOperation
+            └── 读取 {PackageName}_{Version}.hash
+                    ├── 成功 → PackageHash
+                    └── 失败 → Error
+                            ↓
+LoadEditorPackageManifest
+    └── LoadEditorPackageManifestOperation
+            ├── 读取 {PackageName}_{Version}.bytes
+            ├── 验证哈希值
+            └── 反序列化清单
+                    ├── 成功 → Manifest
+                    └── 失败 → Error
+```
+
+### DEFSLoadBundleOperation
+
+加载资源包操作，支持虚拟下载模式和异步模拟延迟。
+
+```
+状态流程：
+CheckExist
+    ├── 文件存在 → LoadAssetBundle
+    └── 文件不存在 → DownloadFile
+                            ↓
+DownloadFile
+    └── DownloadVirtualBundleOperation
+            ├── 模拟下载进度
+            └── 记录下载完成
+                    ↓
+LoadAssetBundle
+    └── 等待模拟帧数
+            ↓
+CheckResult
+    └── 创建 VirtualBundleResult → Status = Succeed
+```
+
+#### 状态机枚举
+
+```csharp
+private enum ESteps
+{
+    None,
+    CheckExist,       // 检查文件是否存在
+    DownloadFile,     // 下载文件（虚拟下载）
+    AbortDownload,    // 中断下载
+    LoadAssetBundle,  // 加载资源包（模拟延迟）
+    CheckResult,      // 检查结果
+    Done              // 完成
+}
+```
+
+### DownloadVirtualBundleOperation
+
+虚拟下载操作，模拟网络下载行为。
+
+**特性：**
+- 使用 `VirtualFileDownloader` 模拟下载进度
+- 支持失败重试机制
+- 下载完成后记录到 `_records` 字典
+
+```
+状态流程：
+CheckExists
+    ├── 文件已记录 → Status = Succeed
+    └── 文件未记录 → CreateRequest
+                            ↓
+CreateRequest
+    └── DownloadSimulateRequestArgs
+            ├── URL = BundleName
+            ├── FileSize = Bundle.FileSize
+            └── DownloadSpeed = VirtualDownloadSpeed
+                    ↓
+CheckRequest
+    ├── 下载成功 → RecordDownloadFile() → Status = Succeed
+    └── 下载失败 → TryAgain 或 Status = Failed
+```
+
+---
+
+## 内部操作类
+
+### LoadEditorPackageVersionOperation
+
+从本地文件加载包裹版本号。
+
+| 属性 | 说明 |
+|------|------|
+| `PackageVersion` | 读取到的版本号字符串 |
+
+### LoadEditorPackageHashOperation
+
+从本地文件加载包裹哈希值。
+
+| 属性 | 说明 |
+|------|------|
+| `PackageHash` | 读取到的哈希值字符串 |
+
+### LoadEditorPackageManifestOperation
+
+加载并反序列化资源清单。
+
+| 属性 | 说明 |
+|------|------|
+| `Manifest` | 反序列化后的清单对象 |
+
+**处理流程：**
+1. 读取清单二进制文件
+2. 使用哈希值验证文件完整性
+3. 反序列化为 `PackageManifest` 对象
+
+---
+
+## 工作原理
+
+### 资源加载机制
+
+```
+用户请求加载资源
+        │
+        ▼
+DefaultEditorFileSystem.LoadBundleFile()
+        │
+        ▼
+DEFSLoadBundleOperation
+        │
+        ▼
+创建 VirtualBundleResult
+        │
+        ▼
+VirtualBundleResult.LoadAssetAsync()
+        │
+        ▼
+VirtualBundleLoadAssetOperation
+        │
+        ▼
+AssetDatabase.LoadAssetAtPath()  ← Unity 编辑器 API
+        │
+        ▼
+返回资源对象
+```
+
+### 虚拟下载模式
+
+当 `VirtualDownloadMode = true` 时：
+
+1. **首次加载**：资源被视为"未下载"，需要执行虚拟下载
+2. **虚拟下载**：使用 `VirtualFileDownloader` 模拟下载进度
+3. **记录完成**：下载完成后将 BundleGUID 记录到 `_records` 字典
+4. **后续加载**：检查 `_records` 字典，已记录的资源直接加载
+
+```csharp
+// 记录下载完成的文件
+protected readonly Dictionary<string, string> _records;
+
+// 检查文件是否存在
+public virtual bool Exists(PackageBundle bundle)
+{
+    if (VirtualDownloadMode)
+        return _records.ContainsKey(bundle.BundleGUID);
+    else
+        return true;
+}
+```
+
+### 异步模拟延迟
+
+通过 `AsyncSimulateMinFrame` 和 `AsyncSimulateMaxFrame` 参数模拟异步加载延迟：
+
+```csharp
+// 获取随机模拟帧数
+public int GetAsyncSimulateFrame()
+{
+    return UnityEngine.Random.Range(AsyncSimulateMinFrame, AsyncSimulateMaxFrame + 1);
+}
+
+// 在 DEFSLoadBundleOperation 中等待
+if (_steps == ESteps.LoadAssetBundle)
+{
+    if (_asyncSimulateFrame <= 0)
+        _steps = ESteps.CheckResult;
+    else
+        _asyncSimulateFrame--;
+}
+```
+
+---
+
+## 使用示例
+
+### 基础配置
+
+```csharp
+// 创建编辑器文件系统参数
+var editorParams = FileSystemParameters.CreateDefaultEditorFileSystemParameters(
+    packageRoot: "Assets/GameRes/Bundles/DefaultPackage"
+);
+
+// 初始化包裹
+var initParams = new EditorSimulateModeParameters();
+initParams.EditorFileSystemParameters = editorParams;
+var initOp = package.InitializeAsync(initParams);
+```
+
+### 启用虚拟下载模式
+
+```csharp
+var editorParams = FileSystemParameters.CreateDefaultEditorFileSystemParameters(
+    packageRoot: "Assets/GameRes/Bundles/DefaultPackage"
+);
+
+// 启用虚拟下载模式
+editorParams.AddParameter(FileSystemParametersDefine.VIRTUAL_DOWNLOAD_MODE, true);
+editorParams.AddParameter(FileSystemParametersDefine.VIRTUAL_DOWNLOAD_SPEED, 1024 * 100); // 100KB/s
+```
+
+### 配置异步模拟延迟
+
+```csharp
+var editorParams = FileSystemParameters.CreateDefaultEditorFileSystemParameters(
+    packageRoot: "Assets/GameRes/Bundles/DefaultPackage"
+);
+
+// 设置异步加载延迟 1-3 帧
+editorParams.AddParameter(FileSystemParametersDefine.ASYNC_SIMULATE_MIN_FRAME, 1);
+editorParams.AddParameter(FileSystemParametersDefine.ASYNC_SIMULATE_MAX_FRAME, 3);
+```
+
+### 模拟 WebGL 模式
+
+```csharp
+var editorParams = FileSystemParameters.CreateDefaultEditorFileSystemParameters(
+    packageRoot: "Assets/GameRes/Bundles/DefaultPackage"
+);
+
+// 启用 WebGL 模拟模式
+editorParams.AddParameter(FileSystemParametersDefine.VIRTUAL_WEBGL_MODE, true);
+```
+
+---
+
+## 参数常量
+
+```csharp
+// 模拟模式参数
+FileSystemParametersDefine.VIRTUAL_WEBGL_MODE        // bool: 模拟 WebGL 模式
+FileSystemParametersDefine.VIRTUAL_DOWNLOAD_MODE     // bool: 模拟下载模式
+FileSystemParametersDefine.VIRTUAL_DOWNLOAD_SPEED    // int: 模拟下载速度（字节/秒）
+FileSystemParametersDefine.ASYNC_SIMULATE_MIN_FRAME  // int: 异步模拟最小帧数
+FileSystemParametersDefine.ASYNC_SIMULATE_MAX_FRAME  // int: 异步模拟最大帧数
+```
+
+---
+
+## 类继承关系
+
+```
+IFileSystem
+    └── DefaultEditorFileSystem
+
+FSInitializeFileSystemOperation
+    └── DEFSInitializeOperation
+
+FSRequestPackageVersionOperation
+    └── DEFSRequestPackageVersionOperation
+
+FSLoadPackageManifestOperation
+    └── DEFSLoadPackageManifestOperation
+
+FSLoadBundleOperation
+    └── DEFSLoadBundleOperation
+
+FSDownloadFileOperation
+    └── DownloadVirtualBundleOperation
+
+AsyncOperationBase
+    ├── LoadEditorPackageVersionOperation
+    ├── LoadEditorPackageHashOperation
+    └── LoadEditorPackageManifestOperation
+
+BundleResult
+    └── VirtualBundleResult  ← 编辑器模式专用
+```
+
+---
+
+## 注意事项
+
+1. **仅限编辑器**：此文件系统仅在 Unity 编辑器中有效
+2. **需要构建清单**：虽然不需要构建 AssetBundle，但需要构建资源清单文件
+3. **VirtualBundle 类型**：只支持 `EBuildBundleType.VirtualBundle` 类型的资源包
+4. **WebGL 模式限制**：`VirtualWebGLMode` 下不支持同步加载（`WaitForAsyncComplete`）
+5. **性能差异**：编辑器模式下的加载性能与真机不同，仅供开发调试使用

Assets/YooAsset/Runtime/FileSystem/DefaultEditorFileSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 10ca037f4f07977458b8e94e4ea0f32c
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultUnpackFileSystem/README.md

@@ -0,0 +1,385 @@
+# DefaultUnpackFileSystem 解压文件系统
+
+## 模块概述
+
+DefaultUnpackFileSystem 是 YooAsset 的**解压文件系统**，专为处理 Android 和 OpenHarmony 平台的内置资源解压需求而设计。该文件系统继承自 `DefaultCacheFileSystem`，复用其完整的下载、验证、缓存功能，仅重定义存储目录结构。
+
+### 核心特性
+
+- **继承复用**：完全继承 DefaultCacheFileSystem 的所有功能
+- **独立存储**：使用独立的目录存储解压后的资源
+- **本地下载**：通过 WWW 路径从 StreamingAssets "下载"资源
+- **平台适配**：解决 Android APK 内文件无法直接访问的问题
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **平台兼容** | 解决 Android/OpenHarmony 平台 APK 内文件访问限制 |
+| **代码复用** | 继承 DefaultCacheFileSystem，避免重复实现 |
+| **资源隔离** | 解压资源与下载缓存分开存储，便于管理 |
+| **透明集成** | 作为 DefaultBuildinFileSystem 的内部组件工作 |
+
+---
+
+## 文件结构
+
+```
+DefaultUnpackFileSystem/
+├── DefaultUnpackFileSystem.cs           # 解压文件系统主类
+├── DefaultUnpackFileSystemDefine.cs     # 常量定义
+└── DefaultUnpackRemoteServices.cs       # 本地资源服务接口
+```
+
+---
+
+## 核心类说明
+
+### DefaultUnpackFileSystem
+
+解压文件系统主类，继承自 `DefaultCacheFileSystem`。
+
+```csharp
+internal class DefaultUnpackFileSystem : DefaultCacheFileSystem
+{
+    public override void OnCreate(string packageName, string rootDirectory)
+    {
+        base.OnCreate(packageName, rootDirectory);
+
+        // 重写保存根目录和临时目录
+        _cacheBundleFilesRoot = PathUtility.Combine(_packageRoot, "UnpackBundleFiles");
+        _cacheManifestFilesRoot = PathUtility.Combine(_packageRoot, "UnpackManifestFiles");
+        _tempFilesRoot = PathUtility.Combine(_packageRoot, "UnpackTempFiles");
+    }
+}
+```
+
+#### 继承的功能
+
+由于继承自 `DefaultCacheFileSystem`，DefaultUnpackFileSystem 拥有以下完整功能：
+
+| 功能 | 说明 |
+|------|------|
+| 文件下载 | 通过 DownloadScheduler 下载资源 |
+| 断点续传 | 支持大文件断点续传 |
+| 文件验证 | 多线程 CRC/Hash 验证 |
+| 缓存管理 | 记录已解压文件，避免重复解压 |
+| 加密支持 | 支持 IDecryptionServices 解密 |
+| 覆盖安装检测 | App 版本变更时清理解压缓存 |
+
+### DefaultUnpackFileSystemDefine
+
+常量定义类，定义解压目录名称。
+
+```csharp
+internal class DefaultUnpackFileSystemDefine
+{
+    /// <summary>
+    /// 保存的资源文件的文件夹名称
+    /// </summary>
+    public const string SaveBundleFilesFolderName = "UnpackBundleFiles";
+
+    /// <summary>
+    /// 保存的清单文件的文件夹名称
+    /// </summary>
+    public const string SaveManifestFilesFolderName = "UnpackManifestFiles";
+
+    /// <summary>
+    /// 下载的临时文件的文件夹名称
+    /// </summary>
+    public const string TempFilesFolderName = "UnpackTempFiles";
+}
+```
+
+### DefaultUnpackRemoteServices
+
+本地资源服务接口，将 StreamingAssets 路径转换为 WWW 请求路径。
+
+```csharp
+internal class DefaultUnpackRemoteServices : IRemoteServices
+{
+    private readonly string _buildinPackageRoot;
+    protected readonly Dictionary<string, string> _mapping = new Dictionary<string, string>(10000);
+
+    public DefaultUnpackRemoteServices(string buildinPackRoot)
+    {
+        _buildinPackageRoot = buildinPackRoot;
+    }
+
+    // 主地址和备用地址相同（本地文件）
+    string IRemoteServices.GetRemoteMainURL(string fileName)
+    {
+        return GetFileLoadURL(fileName);
+    }
+
+    string IRemoteServices.GetRemoteFallbackURL(string fileName)
+    {
+        return GetFileLoadURL(fileName);
+    }
+
+    private string GetFileLoadURL(string fileName)
+    {
+        if (_mapping.TryGetValue(fileName, out string url) == false)
+        {
+            string filePath = PathUtility.Combine(_buildinPackageRoot, fileName);
+            url = DownloadSystemHelper.ConvertToWWWPath(filePath);
+            _mapping.Add(fileName, url);
+        }
+        return url;
+    }
+}
+```
+
+#### 路径转换示例
+
+```
+输入文件名: bundle_abc123.bundle
+
+StreamingAssets 路径:
+  {Application.streamingAssetsPath}/DefaultPackage/bundle_abc123.bundle
+
+WWW 请求路径 (Android):
+  jar:file:///data/app/com.example.game.apk!/assets/DefaultPackage/bundle_abc123.bundle
+```
+
+---
+
+## 目录结构
+
+### 与 DefaultCacheFileSystem 对比
+
+| 目录类型 | DefaultCacheFileSystem | DefaultUnpackFileSystem |
+|----------|----------------------|------------------------|
+| 资源文件 | `BundleFiles/` | `UnpackBundleFiles/` |
+| 清单文件 | `ManifestFiles/` | `UnpackManifestFiles/` |
+| 临时文件 | `TempFiles/` | `UnpackTempFiles/` |
+
+### 实际目录结构
+
+```
+{SandboxRoot}/{PackageName}/
+├── BundleFiles/              # DefaultCacheFileSystem 下载缓存
+│   └── ...
+├── ManifestFiles/            # DefaultCacheFileSystem 清单缓存
+│   └── ...
+├── UnpackBundleFiles/        # DefaultUnpackFileSystem 解压缓存
+│   ├── {Hash[0:2]}/
+│   │   └── {BundleGUID}/
+│   │       ├── __data
+│   │       └── __info
+│   └── ...
+├── UnpackManifestFiles/      # DefaultUnpackFileSystem 清单
+│   └── ...
+└── UnpackTempFiles/          # DefaultUnpackFileSystem 临时文件
+    └── ...
+```
+
+---
+
+## 工作原理
+
+### 解压触发条件
+
+在 `DefaultBuildinFileSystem` 中，以下情况会触发解压：
+
+```csharp
+protected virtual bool IsUnpackBundleFile(PackageBundle bundle)
+{
+    if (Belong(bundle) == false)
+        return false;
+
+#if UNITY_ANDROID || UNITY_OPENHARMONY
+    // Android/OpenHarmony 平台
+    if (bundle.Encrypted)
+        return true;           // 加密资源需要解压
+
+    if (bundle.BundleType == (int)EBuildBundleType.RawBundle)
+        return true;           // 原生文件需要解压
+
+    return false;              // 普通 AssetBundle 不需要解压
+#else
+    return false;              // 其他平台不需要解压
+#endif
+}
+```
+
+### 解压流程
+
+```
+DefaultBuildinFileSystem
+    │
+    ├── NeedUnpack(bundle) 检查
+    │       └── IsUnpackBundleFile(bundle)
+    │               ├── Android/OpenHarmony 平台
+    │               │       ├── 加密资源 → true
+    │               │       └── RawBundle → true
+    │               └── 其他平台 → false
+    │
+    ├── 需要解压时
+    │       └── _unpackFileSystem.DownloadFileAsync(bundle, options)
+    │               └── DefaultUnpackRemoteServices.GetRemoteMainURL()
+    │                       └── 返回 StreamingAssets 的 WWW 路径
+    │                               ↓
+    │               └── DownloadAndCacheRemoteFileOperation
+    │                       ├── 从 APK 内 "下载" 资源
+    │                       ├── 验证文件完整性
+    │                       └── 保存到 UnpackBundleFiles 目录
+    │
+    └── 加载资源时
+            └── _unpackFileSystem.LoadBundleFile(bundle)
+                    └── 从 UnpackBundleFiles 加载
+```
+
+### 资源加载委托
+
+```csharp
+// DefaultBuildinFileSystem.LoadBundleFile()
+public virtual FSLoadBundleOperation LoadBundleFile(PackageBundle bundle)
+{
+    // 需要解压的资源，委托给解压文件系统加载
+    if (IsUnpackBundleFile(bundle))
+    {
+        return _unpackFileSystem.LoadBundleFile(bundle);
+    }
+
+    // 普通资源直接从 StreamingAssets 加载
+    // ...
+}
+```
+
+---
+
+## 与 DefaultBuildinFileSystem 集成
+
+### 初始化流程
+
+```csharp
+// DefaultBuildinFileSystem.OnCreate()
+public virtual void OnCreate(string packageName, string packageRoot)
+{
+    // ... 基础初始化 ...
+
+    // 创建解压文件系统
+    var remoteServices = new DefaultUnpackRemoteServices(_packageRoot);
+    _unpackFileSystem = new DefaultUnpackFileSystem();
+
+    // 传递配置参数
+    _unpackFileSystem.SetParameter(REMOTE_SERVICES, remoteServices);
+    _unpackFileSystem.SetParameter(INSTALL_CLEAR_MODE, InstallClearMode);
+    _unpackFileSystem.SetParameter(FILE_VERIFY_LEVEL, FileVerifyLevel);
+    _unpackFileSystem.SetParameter(FILE_VERIFY_MAX_CONCURRENCY, FileVerifyMaxConcurrency);
+    _unpackFileSystem.SetParameter(APPEND_FILE_EXTENSION, AppendFileExtension);
+    _unpackFileSystem.SetParameter(DECRYPTION_SERVICES, DecryptionServices);
+    _unpackFileSystem.SetParameter(COPY_LOCAL_FILE_SERVICES, CopyLocalFileServices);
+
+    // 使用指定的解压根目录
+    _unpackFileSystem.OnCreate(packageName, UnpackFileSystemRoot);
+}
+```
+
+### 方法委托关系
+
+| DefaultBuildinFileSystem 方法 | 解压资源时的委托目标 |
+|------------------------------|-------------------|
+| `LoadBundleFile()` | `_unpackFileSystem.LoadBundleFile()` |
+| `GetBundleFilePath()` | `_unpackFileSystem.GetBundleFilePath()` |
+| `ReadBundleFileData()` | `_unpackFileSystem.ReadBundleFileData()` |
+| `ReadBundleFileText()` | `_unpackFileSystem.ReadBundleFileText()` |
+| `DownloadFileAsync()` | `_unpackFileSystem.DownloadFileAsync()` |
+| `ClearCacheFilesAsync()` | `_unpackFileSystem.ClearCacheFilesAsync()` |
+
+---
+
+## 使用场景
+
+### 场景 1：Android 加密资源
+
+```
+问题：Android 平台无法直接从 APK 内读取文件进行解密
+解决：先解压到沙盒，再从沙盒读取并解密
+
+流程：
+1. 检测到加密资源 → IsUnpackBundleFile() = true
+2. 首次加载 → NeedUnpack() = true
+3. 执行解压 → DownloadFileAsync() 从 APK 复制到沙盒
+4. 后续加载 → NeedUnpack() = false，直接从沙盒加载
+```
+
+### 场景 2：Android 原生文件
+
+```
+问题：RawBundle 需要通过文件路径访问，APK 内路径不可直接访问
+解决：解压到沙盒，返回沙盒内的文件路径
+
+流程：
+1. 检测到 RawBundle → IsUnpackBundleFile() = true
+2. 首次访问 → 解压到 UnpackBundleFiles
+3. GetBundleFilePath() 返回沙盒路径
+4. 业务代码使用标准文件 API 访问
+```
+
+### 场景 3：普通 AssetBundle
+
+```
+情况：Android 平台的普通（未加密）AssetBundle
+处理：不需要解压，Unity 可以直接从 APK 内加载
+
+流程：
+1. IsUnpackBundleFile() = false
+2. 直接使用 AssetBundle.LoadFromFile() 加载
+3. Unity 内部处理 APK 访问
+```
+
+---
+
+## 类继承关系
+
+```
+IFileSystem
+    └── DefaultCacheFileSystem
+            └── DefaultUnpackFileSystem  ← 仅重写目录名称
+
+IRemoteServices
+    └── DefaultUnpackRemoteServices      ← 本地 WWW 路径服务
+```
+
+---
+
+## 配置参数
+
+DefaultUnpackFileSystem 继承 DefaultCacheFileSystem 的所有参数：
+
+| 参数 | 类型 | 说明 |
+|------|------|------|
+| `REMOTE_SERVICES` | `IRemoteServices` | 由 DefaultUnpackRemoteServices 提供 |
+| `INSTALL_CLEAR_MODE` | `EOverwriteInstallClearMode` | 覆盖安装清理模式 |
+| `FILE_VERIFY_LEVEL` | `EFileVerifyLevel` | 文件验证级别 |
+| `FILE_VERIFY_MAX_CONCURRENCY` | `int` | 验证并发数 |
+| `APPEND_FILE_EXTENSION` | `bool` | 追加文件扩展名 |
+| `DECRYPTION_SERVICES` | `IDecryptionServices` | 解密服务 |
+| `COPY_LOCAL_FILE_SERVICES` | `ICopyLocalFileServices` | 本地拷贝服务 |
+
+---
+
+## 注意事项
+
+1. **内部组件**：DefaultUnpackFileSystem 是 DefaultBuildinFileSystem 的内部组件，不建议单独使用
+2. **平台限定**：解压功能仅在 Android 和 OpenHarmony 平台生效
+3. **存储占用**：解压会额外占用设备存储空间（相当于资源的两份拷贝）
+4. **首次加载**：需要解压的资源首次加载会有额外耗时
+5. **自动管理**：解压缓存由系统自动管理，包括覆盖安装时的清理
+6. **继承完整性**：继承了 DefaultCacheFileSystem 的所有功能，包括断点续传、多线程验证等
+
+---
+
+## 与其他文件系统对比
+
+| 特性 | DefaultUnpackFileSystem | DefaultCacheFileSystem |
+|------|------------------------|----------------------|
+| 数据来源 | StreamingAssets (本地) | 远程服务器 |
+| 主/备用地址 | 相同（本地路径） | 不同（CDN 地址） |
+| 存储目录 | UnpackXxxFiles | XxxFiles |
+| 使用方式 | 作为内部组件 | 独立使用 |
+| 继承关系 | 子类 | 父类 |

Assets/YooAsset/Runtime/FileSystem/DefaultUnpackFileSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 402224e40b04b0d458f12f5925d229b7
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/DefaultWebRemoteFileSystem.cs

@@ -10,6 +10,11 @@ namespace YooAsset
     /// </summary>
     internal class DefaultWebRemoteFileSystem : IFileSystem
     {
+        /// <summary>
+        /// 下载后台接口
+        /// </summary>
+        public IDownloadBackend DownloadBackend { private set; get; }
+
         /// <summary>
         /// 包裹名称
         /// </summary>
@@ -38,6 +43,11 @@ namespace YooAsset
         }
 
         #region 自定义参数
+        /// <summary>
+        /// 自定义参数：UnityWebRequest 创建委托
+        /// </summary>
+        public UnityWebRequestCreator WebRequestCreator { private set; get; }
+
         /// <summary>
         /// 禁用Unity的网络缓存
         /// </summary>
@@ -104,7 +114,15 @@ namespace YooAsset
 
         public virtual void SetParameter(string name, object value)
         {
-            if (name == FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE)
+            if (name == FileSystemParametersDefine.DOWNLOAD_BACKEND)
+            {
+                DownloadBackend = (IDownloadBackend)value;
+            }
+            else if (name == FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR)
+            {
+                WebRequestCreator = (UnityWebRequestCreator)value;
+            }
+            else if (name == FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE)
             {
                 DisableUnityWebCache = Convert.ToBoolean(value);
             }
@@ -128,9 +146,18 @@ namespace YooAsset
         public virtual void OnCreate(string packageName, string packageRoot)
         {
             PackageName = packageName;
+
+            // 创建默认的下载后台接口
+            if (DownloadBackend == null)
+                DownloadBackend = new UnityWebRequestBackend(WebRequestCreator);
         }
         public virtual void OnDestroy()
         {
+            if (DownloadBackend != null)
+            {
+                DownloadBackend.Dispose();
+                DownloadBackend = null;
+            }
         }
 
         public virtual bool Belong(PackageBundle bundle)

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/Operation/DWRFSLoadBundleOperation.cs

@@ -41,13 +41,13 @@ namespace YooAsset
 
                     if (_bundle.Encrypted)
                     {
-                        _loadWebAssetBundleOp = new LoadWebEncryptAssetBundleOperation(_bundle, options, _fileSystem.DecryptionServices);
+                        _loadWebAssetBundleOp = new LoadWebEncryptAssetBundleOperation(_bundle, options, _fileSystem.DecryptionServices, _fileSystem.DownloadBackend);
                         _loadWebAssetBundleOp.StartOperation();
                         AddChildOperation(_loadWebAssetBundleOp);
                     }
                     else
                     {
-                        _loadWebAssetBundleOp = new LoadWebNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache);
+                        _loadWebAssetBundleOp = new LoadWebNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache, _fileSystem.DownloadBackend);
                         _loadWebAssetBundleOp.StartOperation();
                         AddChildOperation(_loadWebAssetBundleOp);
                     }

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/Operation/DWRFSLoadPackageManifestOperation.cs

@@ -38,7 +38,7 @@ namespace YooAsset
             {
                 if (_requestWebPackageHashOp == null)
                 {
-                    _requestWebPackageHashOp = new RequestWebPackageHashOperation(_fileSystem.RemoteServices, _fileSystem.PackageName, _packageVersion, _timeout);
+                    _requestWebPackageHashOp = new RequestWebPackageHashOperation(_fileSystem.RemoteServices, _fileSystem.DownloadBackend, _fileSystem.PackageName, _packageVersion, _timeout);
                     _requestWebPackageHashOp.StartOperation();
                     AddChildOperation(_requestWebPackageHashOp);
                 }
@@ -67,7 +67,8 @@ namespace YooAsset
                     string packageName = _fileSystem.PackageName;
                     var manifestServices = _fileSystem.ManifestServices;
                     var remoteServices = _fileSystem.RemoteServices;
-                    _loadWebPackageManifestOp = new LoadWebPackageManifestOperation(manifestServices, remoteServices, packageName, _packageVersion, packageHash, _timeout);
+                    var downloadBackend = _fileSystem.DownloadBackend;
+                    _loadWebPackageManifestOp = new LoadWebPackageManifestOperation(manifestServices, remoteServices, downloadBackend, packageName, _packageVersion, packageHash, _timeout);
                     _loadWebPackageManifestOp.StartOperation();
                     AddChildOperation(_loadWebPackageManifestOp);
                 }

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/Operation/DWRFSRequestPackageVersionOperation.cs

@@ -36,7 +36,7 @@ namespace YooAsset
             {
                 if (_requestWebPackageVersionOp == null)
                 {
-                    _requestWebPackageVersionOp = new RequestWebPackageVersionOperation(_fileSystem.RemoteServices, _fileSystem.PackageName, _appendTimeTicks, _timeout);
+                    _requestWebPackageVersionOp = new RequestWebPackageVersionOperation(_fileSystem.RemoteServices, _fileSystem.DownloadBackend, _fileSystem.PackageName, _appendTimeTicks, _timeout);
                     _requestWebPackageVersionOp.StartOperation();
                     AddChildOperation(_requestWebPackageVersionOp);
                 }

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/README.md

@@ -0,0 +1,504 @@
+# DefaultWebRemoteFileSystem Web远程文件系统
+
+## 模块概述
+
+DefaultWebRemoteFileSystem 是 YooAsset 的 **Web 远程文件系统**，专为从远程服务器直接加载资源而设计。该文件系统不缓存文件到本地，每次都从远程 URL 加载资源，适用于 WebGL 平台的跨域资源加载或特殊的网络资源场景。
+
+### 核心特性
+
+- **无本地缓存**：直接从远程 URL 加载，不写入本地文件
+- **跨域支持**：通过 `IRemoteServices` 支持跨域资源下载
+- **Unity 缓存控制**：可选择禁用 Unity 的 Web 请求缓存
+- **加密支持**：支持 `IWebDecryptionServices` 解密 Web 资源
+- **失败重试**：内置下载失败自动重试机制
+
+---
+
+## 设计目标
+
+| 目标 | 说明 |
+|------|------|
+| **轻量级** | 无缓存管理，结构简洁 |
+| **即时加载** | 每次从远程获取最新资源 |
+| **跨域兼容** | 支持 WebGL 平台的跨域限制处理 |
+| **可配置** | 支持 Unity Web 缓存控制和自定义解密 |
+
+---
+
+## 文件结构
+
+```
+DefaultWebRemoteFileSystem/
+├── DefaultWebRemoteFileSystem.cs           # 文件系统主类
+└── Operation/                              # 操作类
+    ├── DWRFSInitializeOperation.cs         # 初始化操作
+    ├── DWRFSRequestPackageVersionOperation.cs  # 请求版本操作
+    ├── DWRFSLoadPackageManifestOperation.cs    # 加载清单操作
+    └── DWRFSLoadBundleOperation.cs         # 加载资源包操作
+```
+
+### 依赖的共享模块
+
+DefaultWebRemoteFileSystem 依赖 `WebGame` 目录下的共享操作类：
+
+```
+FileSystem/WebGame/Operation/
+├── LoadWebAssetBundleOperation.cs          # Web 资源包加载基类
+├── LoadWebNormalAssetBundleOperation.cs    # 普通资源包加载
+├── LoadWebEncryptAssetBundleOperation.cs   # 加密资源包加载
+├── RequestWebPackageVersionOperation.cs    # 请求版本文件
+├── RequestWebPackageHashOperation.cs       # 请求哈希文件
+└── LoadWebPackageManifestOperation.cs      # 加载清单文件
+```
+
+---
+
+## 核心类说明
+
+### DefaultWebRemoteFileSystem
+
+Web 远程文件系统的主类，实现 `IFileSystem` 接口。
+
+#### 基本属性
+
+| 属性 | 类型 | 说明 |
+|------|------|------|
+| `PackageName` | `string` | 包裹名称 |
+| `FileRoot` | `string` | 始终返回空字符串（无本地存储） |
+| `FileCount` | `int` | 始终返回 0（无本地文件） |
+| `DownloadBackend` | `IDownloadBackend` | 下载后台接口 |
+
+#### 自定义参数
+
+| 参数 | 类型 | 默认值 | 说明 |
+|------|------|--------|------|
+| `DisableUnityWebCache` | `bool` | `false` | 禁用 Unity 的网络缓存 |
+| `RemoteServices` | `IRemoteServices` | - | 远程服务接口（必需） |
+| `DecryptionServices` | `IWebDecryptionServices` | `null` | Web 解密服务接口 |
+| `ManifestServices` | `IManifestRestoreServices` | `null` | 清单服务接口 |
+
+#### 核心方法
+
+```csharp
+// 生命周期
+void OnCreate(string packageName, string packageRoot);
+void OnDestroy();
+void SetParameter(string name, object value);
+
+// 异步操作
+FSInitializeFileSystemOperation InitializeFileSystemAsync();
+FSRequestPackageVersionOperation RequestPackageVersionAsync(bool appendTimeTicks, int timeout);
+FSLoadPackageManifestOperation LoadPackageManifestAsync(string packageVersion, int timeout);
+FSLoadBundleOperation LoadBundleFile(PackageBundle bundle);
+FSClearCacheFilesOperation ClearCacheFilesAsync(...);  // 直接返回完成
+
+// 不支持的操作
+FSDownloadFileOperation DownloadFileAsync(...);  // 抛出 NotImplementedException
+string GetBundleFilePath(...);                   // 抛出 NotImplementedException
+byte[] ReadBundleFileData(...);                  // 抛出 NotImplementedException
+string ReadBundleFileText(...);                  // 抛出 NotImplementedException
+
+// 文件查询（固定返回值）
+bool Belong(PackageBundle bundle);      // 始终返回 true
+bool Exists(PackageBundle bundle);      // 始终返回 true
+bool NeedDownload(PackageBundle bundle);// 始终返回 false
+bool NeedUnpack(PackageBundle bundle);  // 始终返回 false
+bool NeedImport(PackageBundle bundle);  // 始终返回 false
+```
+
+---
+
+## 操作类说明
+
+### DWRFSInitializeOperation
+
+初始化操作，立即完成（无需任何初始化工作）。
+
+```csharp
+internal override void InternalStart()
+{
+    Status = EOperationStatus.Succeed;  // 直接成功
+}
+```
+
+### DWRFSRequestPackageVersionOperation
+
+请求包裹版本操作，从远程服务器获取版本文件。
+
+```
+状态流程：
+RequestPackageVersion
+    └── RequestWebPackageVersionOperation
+            └── 请求 {PackageName}_Version.txt
+                    ├── 成功 → PackageVersion = 文件内容 → Succeed
+                    └── 失败 → Failed
+```
+
+#### 请求地址轮换
+
+```csharp
+// 轮流使用主地址和备用地址
+if (_requestCount % 2 == 0)
+    url = _remoteServices.GetRemoteMainURL(fileName);
+else
+    url = _remoteServices.GetRemoteFallbackURL(fileName);
+
+// 可选：添加时间戳防止缓存
+if (_appendTimeTicks)
+    return $"{url}?{System.DateTime.UtcNow.Ticks}";
+```
+
+### DWRFSLoadPackageManifestOperation
+
+加载资源清单操作，从远程下载并解析清单。
+
+```
+状态流程：
+RequestWebPackageHash
+    └── RequestWebPackageHashOperation
+            └── 请求 {PackageName}_{Version}.hash
+                    ├── 成功 → PackageHash
+                    └── 失败 → Failed
+                            ↓
+LoadWebPackageManifest
+    └── LoadWebPackageManifestOperation
+            └── 请求 {PackageName}_{Version}.bytes
+                    ├── 验证哈希
+                    └── 反序列化清单
+                            ├── 成功 → Manifest → Succeed
+                            └── 失败 → Failed
+```
+
+### DWRFSLoadAssetBundleOperation
+
+加载资源包操作，从远程 URL 直接加载 AssetBundle。
+
+```
+状态流程：
+LoadWebAssetBundle
+    ├── 未加密 → LoadWebNormalAssetBundleOperation
+    │       └── UnityWebRequestAssetBundle.GetAssetBundle()
+    │               ├── 成功 → AssetBundle → AssetBundleResult
+    │               └── 失败 → TryAgain 或 Failed
+    │
+    └── 已加密 → LoadWebEncryptAssetBundleOperation
+            └── DownloadBytesRequest
+                    └── 下载原始字节
+                            └── IWebDecryptionServices.LoadAssetBundle()
+                                    ├── 成功 → AssetBundle → AssetBundleResult
+                                    └── 失败 → TryAgain 或 Failed
+```
+
+#### 状态机枚举
+
+```csharp
+private enum ESteps
+{
+    None,
+    LoadWebAssetBundle,  // 加载 Web 资源包
+    Done                 // 完成
+}
+```
+
+#### 同步加载限制
+
+```csharp
+internal override void InternalWaitForAsyncComplete()
+{
+    if (_steps != ESteps.Done)
+    {
+        _steps = ESteps.Done;
+        Status = EOperationStatus.Failed;
+        Error = "WebGL platform not support sync load method !";
+        UnityEngine.Debug.LogError(Error);
+    }
+}
+```
+
+---
+
+## 共享 Web 操作类
+
+### LoadWebNormalAssetBundleOperation
+
+普通（未加密）AssetBundle 的 Web 加载操作。
+
+```
+CreateRequest
+    └── DownloadAssetBundleRequest
+            ├── URL: 主地址或备用地址（轮换）
+            ├── DisableUnityWebCache: 是否禁用缓存
+            ├── FileHash: 用于 Unity 缓存键
+            └── UnityCRC: CRC 验证
+                    ↓
+CheckRequest
+    ├── 成功 → Result = AssetBundle
+    └── 失败 → TryAgain（重试）或 Failed
+```
+
+#### Unity Web 缓存机制
+
+```csharp
+// 使用 Unity 的内置缓存
+var args = new DownloadAssetBundleRequestArgs(
+    url,
+    timeout: 0,
+    watchdogTime: 0,
+    disableUnityWebCache: _disableUnityWebCache,
+    cacheHash: _bundle.FileHash,    // 缓存键
+    unityCRC: _bundle.UnityCRC      // CRC 验证
+);
+```
+
+### LoadWebEncryptAssetBundleOperation
+
+加密 AssetBundle 的 Web 加载操作。
+
+```
+CreateRequest
+    └── 检查 DecryptionServices
+            ├── null → Failed
+            └── 有效 → DownloadBytesRequest
+                        ↓
+CheckRequest
+    ├── 下载成功 → LoadEncryptedAssetBundle()
+    │       └── IWebDecryptionServices.LoadAssetBundle(fileData)
+    │               ├── 解密成功 → Result = AssetBundle
+    │               └── 解密失败 → Failed
+    └── 下载失败 → TryAgain 或 Failed
+```
+
+#### 加密资源加载
+
+```csharp
+private AssetBundle LoadEncryptedAssetBundle(byte[] fileData)
+{
+    var fileInfo = new WebDecryptFileInfo();
+    fileInfo.BundleName = _bundle.BundleName;
+    fileInfo.FileLoadCRC = _bundle.UnityCRC;
+    fileInfo.FileData = fileData;  // 下载的原始字节
+    var decryptResult = _decryptionServices.LoadAssetBundle(fileInfo);
+    return decryptResult.Result;
+}
+```
+
+---
+
+## 失败重试机制
+
+Web 加载操作内置失败重试机制：
+
+```csharp
+// 检测下载结果
+if (_unityAssetBundleRequestOp.Status == EDownloadRequestStatus.Succeed)
+{
+    _steps = ESteps.Done;
+    Status = EOperationStatus.Succeed;
+    Result = _unityAssetBundleRequestOp.Result;
+}
+else
+{
+    if (_failedTryAgain > 0)
+    {
+        _steps = ESteps.TryAgain;
+        YooLogger.Warning($"Failed download : {url} Try again !");
+    }
+    else
+    {
+        _steps = ESteps.Done;
+        Status = EOperationStatus.Failed;
+        Error = _unityAssetBundleRequestOp.Error;
+    }
+}
+
+// 重新尝试下载（1秒后）
+if (_steps == ESteps.TryAgain)
+{
+    _tryAgainTimer += Time.unscaledDeltaTime;
+    if (_tryAgainTimer > 1f)
+    {
+        _tryAgainTimer = 0f;
+        _failedTryAgain--;
+        _steps = ESteps.CreateRequest;  // 重新创建请求
+    }
+}
+```
+
+---
+
+## 使用示例
+
+### 基础配置
+
+```csharp
+// 创建远程服务接口
+class GameRemoteServices : IRemoteServices
+{
+    public string GetRemoteMainURL(string fileName)
+    {
+        return $"https://cdn.example.com/bundles/{fileName}";
+    }
+    public string GetRemoteFallbackURL(string fileName)
+    {
+        return $"https://cdn-backup.example.com/bundles/{fileName}";
+    }
+}
+
+// 创建 Web 远程文件系统参数
+var webRemoteParams = FileSystemParameters.CreateDefaultWebRemoteFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 初始化包裹（WebGL 模式）
+var initParams = new WebPlayModeParameters();
+initParams.WebServerFileSystemParameters = webServerParams;
+initParams.WebRemoteFileSystemParameters = webRemoteParams;
+var initOp = package.InitializeAsync(initParams);
+```
+
+### 禁用 Unity Web 缓存
+
+```csharp
+var webRemoteParams = FileSystemParameters.CreateDefaultWebRemoteFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 禁用 Unity 的 Web 请求缓存（始终获取最新资源）
+webRemoteParams.AddParameter(FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE, true);
+```
+
+### 配置 Web 解密服务
+
+```csharp
+// 自定义 Web 解密服务
+class GameWebDecryptionServices : IWebDecryptionServices
+{
+    public WebDecryptResult LoadAssetBundle(WebDecryptFileInfo fileInfo)
+    {
+        // 解密下载的字节数据
+        byte[] decryptedData = Decrypt(fileInfo.FileData);
+        AssetBundle bundle = AssetBundle.LoadFromMemory(decryptedData);
+        return new WebDecryptResult { Result = bundle };
+    }
+}
+
+var webRemoteParams = FileSystemParameters.CreateDefaultWebRemoteFileSystemParameters(
+    remoteServices: new GameRemoteServices()
+);
+
+// 设置 Web 解密服务
+webRemoteParams.AddParameter(
+    FileSystemParametersDefine.DECRYPTION_SERVICES,
+    new GameWebDecryptionServices()
+);
+```
+
+### 跨域资源加载
+
+```csharp
+// 跨域远程服务
+class CrossDomainRemoteServices : IRemoteServices
+{
+    private readonly string _mainDomain;
+    private readonly string _fallbackDomain;
+
+    public CrossDomainRemoteServices(string mainDomain, string fallbackDomain)
+    {
+        _mainDomain = mainDomain;
+        _fallbackDomain = fallbackDomain;
+    }
+
+    public string GetRemoteMainURL(string fileName)
+    {
+        // 主 CDN 域名
+        return $"https://{_mainDomain}/assets/{fileName}";
+    }
+
+    public string GetRemoteFallbackURL(string fileName)
+    {
+        // 备用 CDN 域名
+        return $"https://{_fallbackDomain}/assets/{fileName}";
+    }
+}
+
+// 使用跨域服务
+var remoteServices = new CrossDomainRemoteServices(
+    mainDomain: "cdn-us.example.com",
+    fallbackDomain: "cdn-eu.example.com"
+);
+
+var webRemoteParams = FileSystemParameters.CreateDefaultWebRemoteFileSystemParameters(
+    remoteServices: remoteServices
+);
+```
+
+---
+
+## 参数常量
+
+```csharp
+// Unity 缓存控制
+FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE  // bool: 禁用 Unity Web 缓存
+
+// 服务接口
+FileSystemParametersDefine.REMOTE_SERVICES          // IRemoteServices: 远程服务接口
+FileSystemParametersDefine.DECRYPTION_SERVICES      // IWebDecryptionServices: Web 解密服务
+FileSystemParametersDefine.MANIFEST_SERVICES        // IManifestRestoreServices: 清单服务
+```
+
+---
+
+## 类继承关系
+
+```
+IFileSystem
+    └── DefaultWebRemoteFileSystem
+
+FSInitializeFileSystemOperation
+    └── DWRFSInitializeOperation
+
+FSRequestPackageVersionOperation
+    └── DWRFSRequestPackageVersionOperation
+
+FSLoadPackageManifestOperation
+    └── DWRFSLoadPackageManifestOperation
+
+FSLoadBundleOperation
+    └── DWRFSLoadAssetBundleOperation
+
+AsyncOperationBase
+    ├── LoadWebAssetBundleOperation (abstract)
+    │   ├── LoadWebNormalAssetBundleOperation
+    │   └── LoadWebEncryptAssetBundleOperation
+    ├── RequestWebPackageVersionOperation
+    ├── RequestWebPackageHashOperation
+    └── LoadWebPackageManifestOperation
+
+BundleResult
+    └── AssetBundleResult
+```
+
+---
+
+## 与其他文件系统对比
+
+| 特性 | DefaultWebRemoteFileSystem | DefaultCacheFileSystem | DefaultWebServerFileSystem |
+|------|---------------------------|------------------------|---------------------------|
+| 本地缓存 | ❌ 无 | ✅ 有 | ❌ 无 |
+| 支持 RawBundle | ❌ | ✅ | ❌ |
+| 同步加载 | ❌ | ✅ | ❌ |
+| 断点续传 | ❌ | ✅ | ❌ |
+| 跨域支持 | ✅ | ✅ | ✅ |
+| 适用场景 | WebGL 跨域 | 常规游戏 | WebGL 同域 |
+
+---
+
+## 注意事项
+
+1. **仅支持 AssetBundle**：不支持 RawBundle 类型的资源加载
+2. **不支持同步加载**：WebGL 平台限制，`WaitForAsyncComplete()` 会直接返回失败
+3. **无本地缓存**：每次加载都从远程获取，注意网络流量
+4. **部分方法未实现**：`DownloadFileAsync`、`GetBundleFilePath`、`ReadBundleFileData`、`ReadBundleFileText` 会抛出异常
+5. **远程服务必需**：必须配置 `IRemoteServices` 接口
+6. **Unity 缓存**：默认使用 Unity 的 Web 请求缓存，可通过参数禁用
+7. **加密资源**：加密资源需要配置 `IWebDecryptionServices`（注意是 Web 专用接口，非 `IDecryptionServices`）

Assets/YooAsset/Runtime/FileSystem/DefaultWebRemoteFileSystem/README.md.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: 9f6744d0bcd43f84ea4279925784afb2
+TextScriptImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/YooAsset/Runtime/FileSystem/DefaultWebServerFileSystem/DefaultWebServerFileSystem.cs

@@ -24,6 +24,11 @@ namespace YooAsset
         protected readonly Dictionary<string, string> _webFilePathMapping = new Dictionary<string, string>(10000);
         protected string _webPackageRoot = string.Empty;
 
+        /// <summary>
+        /// 下载后台接口
+        /// </summary>
+        public IDownloadBackend DownloadBackend { private set; get; }
+
         /// <summary>
         /// 包裹名称
         /// </summary>
@@ -52,6 +57,11 @@ namespace YooAsset
         }
 
         #region 自定义参数
+        /// <summary>
+        /// 自定义参数：UnityWebRequest 创建委托
+        /// </summary>
+        public UnityWebRequestCreator WebRequestCreator { private set; get; }
+
         /// <summary>
         /// 禁用Unity的网络缓存
         /// </summary>
@@ -113,7 +123,15 @@ namespace YooAsset
 
         public virtual void SetParameter(string name, object value)
         {
-            if (name == FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE)
+            if (name == FileSystemParametersDefine.DOWNLOAD_BACKEND)
+            {
+                DownloadBackend = (IDownloadBackend)value;
+            }
+            else if (name == FileSystemParametersDefine.UNITY_WEB_REQUEST_CREATOR)
+            {
+                WebRequestCreator = (UnityWebRequestCreator)value;
+            }
+            else if (name == FileSystemParametersDefine.DISABLE_UNITY_WEB_CACHE)
             {
                 DisableUnityWebCache = Convert.ToBoolean(value);
             }
@@ -138,9 +156,18 @@ namespace YooAsset
                 _webPackageRoot = GetDefaultWebPackageRoot(packageName);
             else
                 _webPackageRoot = packageRoot;
+
+            // 创建默认的下载后台接口
+            if (DownloadBackend == null)
+                DownloadBackend = new UnityWebRequestBackend(WebRequestCreator);
         }
         public virtual void OnDestroy()
         {
+            if (DownloadBackend != null)
+            {
+                DownloadBackend.Dispose();
+                DownloadBackend = null;
+            }
         }
 
         public virtual bool Belong(PackageBundle bundle)

Assets/YooAsset/Runtime/FileSystem/DefaultWebServerFileSystem/Operation/DWSFSLoadBundleOperation.cs

@@ -41,13 +41,13 @@ namespace YooAsset
 
                     if (_bundle.Encrypted)
                     {
-                        _loadWebAssetBundleOp = new LoadWebEncryptAssetBundleOperation(_bundle, options, _fileSystem.DecryptionServices);
+                        _loadWebAssetBundleOp = new LoadWebEncryptAssetBundleOperation(_bundle, options, _fileSystem.DecryptionServices, _fileSystem.DownloadBackend);
                         _loadWebAssetBundleOp.StartOperation();
                         AddChildOperation(_loadWebAssetBundleOp);
                     }
                     else
                     {
-                        _loadWebAssetBundleOp = new LoadWebNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache);
+                        _loadWebAssetBundleOp = new LoadWebNormalAssetBundleOperation(_bundle, options, _fileSystem.DisableUnityWebCache, _fileSystem.DownloadBackend);
                         _loadWebAssetBundleOp.StartOperation();
                         AddChildOperation(_loadWebAssetBundleOp);
                     }

Assets/YooAsset/Runtime/FileSystem/DefaultWebServerFileSystem/Operation/internal/LoadWebServerCatalogFileOperation.cs

@@ -14,7 +14,7 @@ namespace YooAsset
 
         private readonly DefaultWebServerFileSystem _fileSystem;
         private readonly int _timeout;
-        private UnityWebDataRequestOperation _webDataRequestOp;
+        private IDownloadBytesRequest _webDataRequestOp;
         private ESteps _steps = ESteps.None;
 
         internal LoadWebServerCatalogFileOperation(DefaultWebServerFileSystem fileSystem, int timeout)
@@ -37,16 +37,15 @@ namespace YooAsset
                 {
                     string filePath = _fileSystem.GetCatalogBinaryFileLoadPath();
                     string url = DownloadSystemHelper.ConvertToWWWPath(filePath);
-                    _webDataRequestOp = new UnityWebDataRequestOperation(url, _timeout);
+                    var args = new DownloadDataRequestArgs(url, _timeout, 0);
-                    _webDataRequestOp.StartOperation();
+                    _webDataRequestOp = _fileSystem.DownloadBackend.CreateBytesRequest(args);
-                    AddChildOperation(_webDataRequestOp);
+                    _webDataRequestOp.SendRequest();
                 }
 
-                _webDataRequestOp.UpdateOperation();
                 if (_webDataRequestOp.IsDone == false)
                     return;
 
-                if (_webDataRequestOp.Status == EOperationStatus.Succeed)
+                if (_webDataRequestOp.Status == EDownloadRequestStatus.Succeed)
                 {
                     _steps = ESteps.LoadCatalog;
                 }
@@ -81,11 +80,11 @@ namespace YooAsset
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Succeed;
                 }
-                catch (Exception e)
+                catch (Exception ex)
                 {
                     _steps = ESteps.Done;
                     Status = EOperationStatus.Failed;
-                    Error = $"Failed to load catalog file : {e.Message}";
+                    Error = $"Failed to load catalog file : {ex.Message}";
                 }
             }
         }