Пример:
procedure TForm1.Button1Click(Sender: TObject);
begin
PatBlt(Form1.Canvas.Handle,
0,
0,
Form1.ClientWidth,
Form1.ClientHeight,
WHITENESS);
end;
Источник: Дельфи. Вокруг да около.
procedure TForm1.Button1Click(Sender: TObject);
begin
PatBlt(Form1.Canvas.Handle,
0,
0,
Form1.ClientWidth,
Form1.ClientHeight,
WHITENESS);
end;