[DllImport("user32")]  
private static extern int SendMessage(IntPtr hwnd, int wMsg, int wParam, IntPtr lParam);  
private const int WM_SETREDRAW = 0xB;   


//禁止pnl重绘  
//SendMessage(SelfInfo_pnlContact1.Handle, WM_SETREDRAW, 0, IntPtr.Zero);  

//允许重绘pnl  
//SendMessage(SelfInfo_pnlContact1.Handle, WM_SETREDRAW, 1, IntPtr.Zero);  
  
参数是控件