增加BarChart可用ItemStyle的backgroundColor设置柱条背景颜色

CHANGELOG.md

@@ -1,6 +1,7 @@
 
 # 更新日志
 
+* (2020.03.17) 增加`BarChart`可用`ItemStyle`的`backgroundColor`设置数据项背景颜色
 * (2020.03.17) 增加`SerieData`的`ItemStyle`和`Emphasis`可单独配置数据项样式的支持
 * (2020.03.15) 重构`EmptyCricle`类型的`Symbol`边宽取自`ItemStyle`的`borderWidth`
 * (2020.03.15) 重构`SerieSymbol`，去掉`color`和`opacity`参数，用`ItemStyle`参数代替

Runtime/Helper/SerieHelper.cs

@@ -11,7 +11,7 @@ namespace XCharts
 {
     internal static class SerieHelper
     {
-        internal static Color GetItemBackgroundColor(Serie serie, SerieData serieData, ThemeInfo theme, int index, bool highlight)
+        internal static Color GetItemBackgroundColor(Serie serie, SerieData serieData, ThemeInfo theme, int index, bool highlight, bool useDefault = true)
         {
             var itemStyle = GetItemStyle(serie, serieData);
             var color = Color.clear;
@@ -32,13 +32,14 @@ namespace XCharts
                 color.a *= itemStyle.opacity;
                 return color;
             }
-            else
+            else if (useDefault)
             {
                 color = (Color)theme.GetColor(index);
                 if (highlight) color *= color;
                 color.a = 0.2f;
                 return color;
             }
+            return Color.clear;
         }
 
         internal static Color GetItemColor(Serie serie, SerieData serieData, ThemeInfo theme, int index, bool highlight)

Runtime/Internal/CoordinateChart_DrawBar.cs

@@ -98,9 +98,9 @@ namespace XCharts
                 p4 = ClampInCoordinate(p4);
                 top = ClampInCoordinate(top);
                 serie.dataPoints.Add(top);
-
                 if (serie.show)
                 {
+                    DrawBarBackground(vh, serie, serieData, colorIndex, highlight, pX, pY, space, barWidth, true);
                     Color areaColor = SerieHelper.GetItemColor(serie, serieData, m_ThemeInfo, colorIndex, highlight);
                     Color areaToColor = SerieHelper.GetItemToColor(serie, serieData, m_ThemeInfo, colorIndex, highlight);
                     if (serie.barType == BarType.Zebra)
@@ -231,6 +231,7 @@ namespace XCharts
                 {
                     Color areaColor = SerieHelper.GetItemColor(serie, serieData, m_ThemeInfo, colorIndex, highlight);
                     Color areaToColor = SerieHelper.GetItemToColor(serie, serieData, m_ThemeInfo, colorIndex, highlight);
+                    DrawBarBackground(vh, serie, serieData, colorIndex, highlight, pX, pY, space, barWidth, false);
                     if (serie.barType == BarType.Zebra)
                     {
                         p1 = (p4 + p1) / 2;
@@ -262,6 +263,31 @@ namespace XCharts
             }
         }
 
+        private void DrawBarBackground(VertexHelper vh, Serie serie, SerieData serieData, int colorIndex, bool highlight,
+            float pX, float pY, float space, float barWidth, bool isYAxis)
+        {
+            Color color = SerieHelper.GetItemBackgroundColor(serie, serieData, m_ThemeInfo, colorIndex, highlight, false);
+            if (color != Color.clear)
+            {
+                if (isYAxis)
+                {
+                    Vector3 p1 = new Vector3(coordinateX, pY + space + barWidth);
+                    Vector3 p2 = new Vector3(coordinateX + coordinateWidth, pY + space + barWidth);
+                    Vector3 p3 = new Vector3(coordinateX + coordinateWidth, pY + space);
+                    Vector3 p4 = new Vector3(coordinateX, pY + space);
+                    CheckClipAndDrawPolygon(vh, ref p4, ref p1, ref p2, ref p3, color, color, serie.clip);
+                }
+                else
+                {
+                    Vector3 p1 = new Vector3(pX + space, coordinateY);
+                    Vector3 p2 = new Vector3(pX + space, coordinateY + coordinateHeight);
+                    Vector3 p3 = new Vector3(pX + space + barWidth, coordinateY + coordinateHeight);
+                    Vector3 p4 = new Vector3(pX + space + barWidth, coordinateY);
+                    CheckClipAndDrawPolygon(vh, ref p4, ref p1, ref p2, ref p3, color, color, serie.clip);
+                }
+            }
+        }
+
         private float GetBarGap()
         {
             float gap = 0.3f;