Winforms TabControl 导致 UserControl 的虚假 Paint 事件

Question

对于我们的项目，我们编写了一个用于绘图的 WinForms UserControl。

当我们的控件位于 TabControl 中时，我们会看到一些奇怪的行为 - 我们的控件不断触发 Paint 事件，即使用户绝对没有任何活动。

我们只在 TabControl 中看到这一点。当我们将控件放置在其他容器（例如表单或拆分器）中时，Paint 仅在您期望的情况下才会触发，例如首次显示控件时等。

任何人都可以建议为什么会发生这种情况吗？

这是我们控件的 Paint 处理程序中断点的堆栈跟踪，如果有帮助的话。我们的控件是 BaseGraphXY，它位于 TabControl 上，而 TabControl 位于一些嵌套的 SplitContainer 上。对格式感到抱歉 - 由于某种原因无法让 SO 编辑器停止换行。

OverlordFrontEnd.exe!OverlordFrontEnd.MainForm.graphControl_Paint(object sender =  BI_BaseGraphXY.BaseGraphXY}, System.Windows.Forms.PaintEventArgs e = {ClipRectangle = {X=0,Y=0,Width=1031,Height=408}}) Line 422 C#
System.Windows.Forms.dll!System.Windows.Forms.Control.OnPaint(System.Windows.Forms.PaintEventArgs e) + 0x73 bytes   
BI_AppCore.dll!BI_BaseGraphXY.BaseGraphXY.OnPaint(System.Windows.Forms.PaintEventArgs e = {ClipRectangle = {X=0,Y=0,Width=1031,Height=408}}) Line 377 + 0xb bytes   C#
System.Windows.Forms.dll!System.Windows.Forms.Control.PaintTransparentBackground(System.Windows.Forms.PaintEventArgs e, System.Drawing.Rectangle rectangle, System.Drawing.Region transparentRegion = null) + 0x16c bytes   
System.Windows.Forms.dll!System.Windows.Forms.Control.PaintBackground(System.Windows.Forms.PaintEventArgs e = {ClipRectangle = {X=0,Y=0,Width=1029,Height=406}}, System.Drawing.Rectangle rectangle, System.Drawing.Color backColor, System.Drawing.Point scrollOffset) + 0xbc bytes    
System.Windows.Forms.dll!System.Windows.Forms.Control.PaintBackground(System.Windows.Forms.PaintEventArgs e, System.Drawing.Rectangle rectangle) + 0x63 bytes   
System.Windows.Forms.dll!System.Windows.Forms.Control.OnPaintBackground(System.Windows.Forms.PaintEventArgs pevent) + 0x59 bytes    
System.Windows.Forms.dll!System.Windows.Forms.Control.PaintWithErrorHandling(System.Windows.Forms.PaintEventArgs e = {ClipRectangle = {X=0,Y=0,Width=1029,Height=406}}, short layer, bool disposeEventArgs = false) + 0x74 bytes    
System.Windows.Forms.dll!System.Windows.Forms.Control.WmPaint(ref System.Windows.Forms.Message m) + 0x1ba bytes 
System.Windows.Forms.dll!System.Windows.Forms.Control.WndProc(ref System.Windows.Forms.Message m) + 0x33e bytes 
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.OnMessage(ref System.Windows.Forms.Message m) + 0x10 bytes    
System.Windows.Forms.dll!System.Windows.Forms.Control.ControlNativeWindow.WndProc(ref System.Windows.Forms.Message m) + 0x31 bytes  
System.Windows.Forms.dll!System.Windows.Forms.NativeWindow.Callback(System.IntPtr hWnd, int msg = 15, System.IntPtr wparam, System.IntPtr lparam) + 0x5a bytes  
[Native to Managed Transition]  
[Managed to Native Transition]  
System.Windows.Forms.dll!System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(int dwComponentID, int reason = -1, int pvLoopData = 0) + 0x24e bytes 
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(int reason = -1, System.Windows.Forms.ApplicationContext context = {Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.WinFormsAppContext}) + 0x177 bytes    
System.Windows.Forms.dll!System.Windows.Forms.Application.ThreadContext.RunMessageLoop(int reason, System.Windows.Forms.ApplicationContext context) + 0x61 bytes    
System.Windows.Forms.dll!System.Windows.Forms.Application.Run(System.Windows.Forms.ApplicationContext context) + 0x18 bytes 
Microsoft.VisualBasic.dll!Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun() + 0x81 bytes    
Microsoft.VisualBasic.dll!Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel() + 0xef bytes   
Microsoft.VisualBasic.dll!Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(string[] commandLine) + 0x2c0 bytes 
OverlordFrontEnd.exe!OverlordFrontEnd.Program.Main() Line 36 + 0x10 bytes   C#
[Native to Managed Transition]  
[Managed to Native Transition]  
mscorlib.dll!System.AppDomain.ExecuteAssembly(string assemblyFile, System.Security.Policy.Evidence assemblySecurity, string[] args) + 0x3a bytes    
Microsoft.VisualStudio.HostingProcess.Utilities.dll!Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() + 0x2b bytes  
mscorlib.dll!System.Threading.ThreadHelper.ThreadStart_Context(object state) + 0x66 bytes   
mscorlib.dll!System.Threading.ExecutionContext.Run(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) + 0x6f bytes    
mscorlib.dll!System.Threading.ThreadHelper.ThreadStart() + 0x44 bytes   

Answer 1

选项卡控件确实有一些怪癖，尝试修改 SetStyle：

Me.SetStyle(ControlStyles.UserPaint Or ControlStyles.AllPaintingInWmPaint Or ControlStyles.OptimizedDoubleBuffer Or ControlStyles.DoubleBuffer Or ControlStyles.Selectable Or ControlStyles.ResizeRedraw, True)

Answer 2

我的同事找到了解决该问题的方法：

图形控件的问题是 BackColor 属性默认为 System.Drawing.Color.Transparent。这导致了一种消息的“反馈循环”。我想它应该这样工作？不管怎样，我更改了构造函数以使用 System.Drawing.SystemColors.ControlLightLight 作为默认 BackColor 属性。这似乎抑制了额外的图形绘制。