增加customDrawCallback自定义绘制回调

Demo/Scripts/Demo12_CustomDrawing.cs

@@ -0,0 +1,29 @@
+using UnityEngine;
+using UnityEngine.UI;
+using XCharts;
+
+[DisallowMultipleComponent]
+[ExecuteInEditMode]
+public class Demo12_CustomDrawing : MonoBehaviour
+{
+    LineChart chart;
+    void Awake()
+    {
+        chart = gameObject.GetComponent<LineChart>();
+        if (chart == null) return;
+
+        chart.customDrawCallback = delegate (VertexHelper vh)
+        {
+            var dataPoints = chart.series.series[0].dataPoints;
+            if (dataPoints.Count > 0)
+            {
+                var pos = dataPoints[3];
+                var zeroPos = new Vector3(chart.coordinateX, chart.coordinateY);
+                var startPos = new Vector3(pos.x, zeroPos.y);
+                var endPos = new Vector3(pos.x, zeroPos.y + chart.coordinateHig);
+                ChartDrawer.DrawLine(vh, startPos, endPos, 1, Color.blue);
+                ChartDrawer.DrawCricle(vh,pos,5,Color.blue);
+            }
+        };
+    }
+}