unit MyPanel;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
ExtCtrls;
type
TMyPanel = class(TPanel)
private
{ Private declarations }
protected
{ Protected declarations }
procedure Paint; override;
public
{ Public declarations }
published
{ Published declarations }
end;
procedure Register;
implementation
procedure DrawParentImage(Control: TControl; Dest: TCanvas);
var
SaveIndex: Integer;
DC: HDC;
Position: TPoint;
begin
with Control do
begin
if Parent = nil then
Exit;
DC := Dest.Handle;
SaveIndex := SaveDC(DC);
{$IFDEF DFS_COMPILER_2}
GetViewportOrgEx(DC, @Position);
{$ELSE}
GetViewportOrgEx(DC, Position);
{$ENDIF}
SetViewportOrgEx(DC, Position.X - Left, Position.Y - Top, nil);
IntersectClipRect(DC, 0, 0, Parent.ClientWidth, Parent.ClientHeight);
Parent.Perform(WM_ERASEBKGND, DC, 0);
Parent.Perform(WM_PAINT, DC, 0);
RestoreDC(DC, SaveIndex);
end;
end;
procedure Register;
begin
RegisterComponents('Samples', [TMyPanel]);
end;
procedure TMyPanel.Paint;
var
Bitmap: TBitmap;
begin
if not (csDesigning in ComponentState) then
exit;
Bitmap := TBitmap.Create;
try
Bitmap.Height := ClientRect.Bottom;
Bitmap.Width := ClientRect.Right;
DrawParentImage(Self, Bitmap.Canvas);
canvas.CopyRect(ClientRect, Bitmap.canvas, ClientRect);
finally
Bitmap.free;
end;
end;
end.
