視窗Form淡入淡出的效果

先在form1新增一按鈕，並在按鈕的onClick加入下列程式：

form2.showmodal;

接著新增一個新的視窗為form2，並加入一個timer，其enabled=true 及 interval=100，並記得加入事件喔。最後新增一'離開的'按鈕，然後編輯程式碼如下：

unit Unit2;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, ExtCtrls, StdCtrls;

type
  TForm2 = class(TForm)
    Button1: TButton;
    Timer1: TTimer;
    procedure Timer1Timer(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

procedure TForm2.Timer1Timer(Sender: TObject);
var
     i,j:integer;
begin
  timer1.Enabled:=false;
  i:=0;
  j:=3;
  while(i<255) do
  begin
    i:=i+j;
    form2.AlphaBlendValue:=i;
  end;
  form2.AlphaBlendValue:=255;
end;

procedure TForm2.FormShow(Sender: TObject);
begin
  form2.AlphaBlend:=true;
  form2.AlphaBlendValue:=0;
  timer1.Enabled:=true;
end;

procedure TForm2.FormClose(Sender: TObject; var Action: TCloseAction);
var
  i,j:integer;
begin
  i:=255;
  j:=3;
  while(i>0) do
  begin
    i:=i-j;
    form2.AlphaBlendValue:=i;
  end;
  form2.AlphaBlendValue:=0;
end;

procedure TForm2.Button1Click(Sender: TObject);
begin
  close;
end;

end.