diff --git a/Bin/net40/SunnyUI.Demo.exe b/Bin/net40/SunnyUI.Demo.exe
index 62de2998..5aa42314 100644
Binary files a/Bin/net40/SunnyUI.Demo.exe and b/Bin/net40/SunnyUI.Demo.exe differ
diff --git a/Bin/net40/SunnyUI.dll b/Bin/net40/SunnyUI.dll
index 9c5d7d4e..3cb91732 100644
Binary files a/Bin/net40/SunnyUI.dll and b/Bin/net40/SunnyUI.dll differ
diff --git a/Bin/net5.0-windows/SunnyUI.dll b/Bin/net5.0-windows/SunnyUI.dll
index 181bc41f..1c01cd39 100644
Binary files a/Bin/net5.0-windows/SunnyUI.dll and b/Bin/net5.0-windows/SunnyUI.dll differ
diff --git a/Bin/netcoreapp3.1/SunnyUI.dll b/Bin/netcoreapp3.1/SunnyUI.dll
index 8e634c8a..1153b5ea 100644
Binary files a/Bin/netcoreapp3.1/SunnyUI.dll and b/Bin/netcoreapp3.1/SunnyUI.dll differ
diff --git a/SunnyUI/Charts/UILineChart.cs b/SunnyUI/Charts/UILineChart.cs
index f5e90ffe..1b63df1c 100644
--- a/SunnyUI/Charts/UILineChart.cs
+++ b/SunnyUI/Charts/UILineChart.cs
@@ -674,7 +674,7 @@ namespace Sunny.UI
                 e.Y > Option.Grid.Top && e.Y < Height - Option.Grid.Bottom)
             {
                 IsMouseDown = true;
-                StartPoint = e.Location;
+                StartPoint = StopPoint = e.Location;
             }
         }