Omagen de fondo Form MDI

[[ArdiIIa]]

Te pongo un ejemplo...

Espero que te sirva y FLIZ NAVIDAD !!


......

private
FClientInstance : TFarProc;
FPrevClientProc : TFarProc;
procedure ClientWndProc(var Message: TMessage);

...





procedure TFormMain.FormCreate(Sender: TObject);
begin
FClientInstance := MakeObjectInstance(ClientWndProc);
FPrevClientProc := Pointer(GetWindowLong(ClientHandle,GWL_WNDPROC));
SetWindowLong(ClientHandle,GWL_WNDPROC, LongInt(FClientInstance));
end;




procedure TFormMain.ClientWndProc(var Message: TMessage);
var
Dc : hDC;
Row,col: Integer;
Bit : TBitmap;
begin


with Message do
case Msg of
WM_ERASEBKGND:
begin
DC := TWMEraseBkGnd(Message).Dc;
begin
Bit := TBitmap.Create;
Bit.Width := Image1.Width;
Bit.Height := Image1.Height;
Bit.Canvas.Draw(0,0,Image1.Picture.Graphic);

for Row := 0 to ClientHeight div Bit.Height do
for Col := 0 to ClientWidth div Bit.Width do
BitBlt(Dc,
Col * Bit.Width,
Row * Bit.Height,
Bit.Width,
Bit.Height,
Bit.Canvas.Handle,
0,
0,
SRCCOPY);
Result := 1;
Bit.Free;

End;

Result := 1;
end;
else
Result := CallWindowProc(FPrevClientProc,
ClientHandle,
Msg,
wParam,
lParam);
end;


end;




procedure TFormMain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
SetWindowLong(ClientHandle,GWL_WNDPROC, LongInt(FPrevClientProc));
end;