procedure DrawBorder(Handle: THandle; ADC: HDC);var  R: TRect;  Canvas: TCanvas;  P: TPoint;begin  Canvas := TCanvas.Create;  Canvas.Handle := ADC;  P := Point(0, 0);  Windows.ClientToScreen(Handle, P);  Windows.GetWindowRect(Handle, R);  P.X := P.X - R.Left;  P.Y := P.Y - R.Top;  Windows.GetClientRect(Handle, R);  ///  排除不需要绘制的区域  ///    优点： 1、不会绘出界外  ///           2、当面积比较大如背景，拖拽缩放时不会出现大面积色块问题  ///  ExcludeClipRect(Canvas.Handle, P.X, P.Y, R.Right - R.Left + P.X, R.Bottom - R.Top + P.Y);  Windows.GetWindowRect(Handle, R);  OffsetRect(R, -R.Left, -R.Top);  /// 绘制背景  ///PaintBackground(Canvas, R);  /// 清除剪切区域  SelectClipRgn(Canvas.Handle, 0);  Canvas.Handle := 0;  Canvas.Free;end;