实现窗口从实变透明到消失这是一个例子

unit Unit1;

interface

uses

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);

private

{ Private declarations }

public

{ Public declarations }

end;

Const

WS_EX_LAYERED = $00080000;

LMA_COLORKEY = $00000001;

LMA_ALPHA = $00000002;

var

Form1: TForm1;

Step: integer;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);

var

ExtStyle : LongInt;

begin

Step:=255;

ExtStyle := GetWindowLong(Handle, GWL_EXSTYLE);

SetWindowLong(Handle, GWL_EXSTYLE, ExtStyle or WS_EX_LAYERED);

end;

procedure TForm1.Timer1Timer(Sender: TObject);

begin

if Step0 then

begin

Step:=Step-10;

SetLayeredWindowAttributes(Handle, RGB(0,0,0), Step, LMA_ALPHA or LMA_COLORKEY);

end else

begin

SetLayeredWindowAttributes(Handle, RGB(0,0,0), 255, 1);

Timer1.Enabled:=False;

end;

end;

end.