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;

http://www.cnblogs.com/del/archive/2010/04/19/1715779.html

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