我有一个控件,我必须对其进行较大的修改。我想完全避免重绘,而SuspendLayout和ResumeLayout不够。如何为控件及其子控件暂停绘画?
在我之前的工作中,我们一直在努力获取丰富的UI应用程序以立即流畅地绘画。我们正在使用标准的.Net控件,自定义控件和devexpress控件。
经过大量的搜索和反射器使用后,我遇到了WM_SETREDRAW win32消息。当您更新控件时,这实际上会停止控件绘图,并且可以将IIRC应用于父/包含面板。
这是一个非常简单的类,演示如何使用此消息:
class DrawingControl { [DllImport("user32.dll")] public static extern int SendMessage(IntPtr hWnd, Int32 wMsg, bool wParam, Int32 lParam); private const int WM_SETREDRAW = 11; public static void SuspendDrawing( Control parent ) { SendMessage(parent.Handle, WM_SETREDRAW, false, 0); } public static void ResumeDrawing( Control parent ) { SendMessage(parent.Handle, WM_SETREDRAW, true, 0); parent.Refresh(); } }
有关此内容的讨论更充分-Google for C#和WM_SETREDRAW,例如
C#抖动
暂停版式
并且可能与之相关的是VB中的类似示例:
Public Module Extensions <DllImport("user32.dll")> Private Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Boolean, ByVal lParam As IntPtr) As Integer End Function Private Const WM_SETREDRAW As Integer = 11 ' Extension methods for Control <Extension()> Public Sub ResumeDrawing(ByVal Target As Control, ByVal Redraw As Boolean) SendMessage(Target.Handle, WM_SETREDRAW, True, 0) If Redraw Then Target.Refresh() End If End Sub <Extension()> Public Sub SuspendDrawing(ByVal Target As Control) SendMessage(Target.Handle, WM_SETREDRAW, False, 0) End Sub <Extension()> Public Sub ResumeDrawing(ByVal Target As Control) ResumeDrawing(Target, True) End Sub End Module