所谓双缓冲就是先画到内存画布(如: TBitmap), 然后再转帖到目的地.
譬如下面小程序:
procedure TForm1.FormCreate(Sender: TObject);
begin
Timer1.Interval := ;
Color := clWhite;
end; procedure TForm1.Timer1Timer(Sender: TObject);
begin
Canvas.Pen.Color := Random($FFFFFF);
Canvas.MoveTo(Random(ClientWidth), Random(ClientHeight));
Canvas.LineTo(Random(ClientWidth), Random(ClientHeight));
end;
改为双缓冲绘图可以是:
var
bit: TBitmap; procedure TForm1.FormCreate(Sender: TObject);
begin
Timer1.Interval := ;
bit := TBitmap.Create;
bit.Width := ClientWidth;
bit.Height := ClientHeight;
end; procedure TForm1.Timer1Timer(Sender: TObject);
begin
bit.Canvas.Pen.Color := Random($FFFFFF);
bit.Canvas.MoveTo(Random(bit.Width), Random(bit.Height));
bit.Canvas.LineTo(Random(bit.Width), Random(bit.Height));
Self.Canvas.Draw(, , bit);
end; procedure TForm1.FormDestroy(Sender: TObject);
begin
bit.Free;
end;