問題來源:
http://www.cnblogs.com/del/archive/2009/12/22/1629717.html#2096734
1、使用 TransparentColor、TransparentColorValue 給窗體指定透明色;
2、繪制非透明色的文本, 用 TLabel 呈現(xiàn)文本也可;
3、處理 WM_NCHITTEST 消息使窗體能夠被拖動;
4、用 Esc 鍵退出.
測試代碼:
unit Unit1;interfaceuses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, ExtCtrls;type TForm1 = class(TForm) Timer1: TTimer; procedure FormCreate(Sender: TObject); procedure Timer1Timer(Sender: TObject); procedure FormKeyPress(Sender: TObject; var Key: Char); private protected procedure WMNCHitTest(var Message: TWMNCHitTest); message WM_NCHITTEST; public end;var Form1: TForm1;implementation{$R *.dfm}procedure TForm1.FormCreate(Sender: TObject);begin FormStyle := fsStayOnTop; BorderStyle := bsNone; TransparentColor := True; TransparentColorValue := Color; Font.Size := 72; Font.Name := 'Arial Black';// DoubleBuffered := True;end;procedure TForm1.FormKeyPress(Sender: TObject; var Key: Char);begin if Key = Chr(27) then Close;end;procedure TForm1.Timer1Timer(Sender: TObject);var str: string;begin str := TimeToStr(Now); ClientWidth := Canvas.TextWidth(str); ClientHeight := Canvas.TextHeight(str); Canvas.Lock; Canvas.Brush.Color := Color; Canvas.FillRect(ClientRect); Canvas.Brush.Style := bsClear; Canvas.Font.Color := clBlack; Canvas.TextOut(1, 1, str); Canvas.Font.Color := clRed; Canvas.TextOut(0, 0, str); Canvas.Brush.Style := bsSolid; Canvas.Unlock;end;procedure TForm1.WMNCHitTest(var Message: TWMNCHitTest);begin Message.Result := HTCAPTION;end;end.
