请求30秒倒计时程序

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    Timer1: TTimer;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    Button5: TButton;
    procedure Button1Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button5Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

uses Unit2, TimerDlg;

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
  SetDlgAutoClose(15*1000, True);
  ShowMessage('This message box will close automatically,' + #13#10 +
    'after fifteen seconds.');
end;

procedure TForm1.Button3Click(Sender: TObject);
begin
  SetDlgAutoClose(8000, Sender = Button3);
  MessageBox(Handle, PChar('这是一个测试例子' +
    #13#10 + '此消息框将在 8 秒钟后自动关闭' + #13#10 +
    '只需要在调用消息框和对话框之前调用一个函数' + #13#10 +
    '就可以方便的实现这种效果'),
    '定时自动关闭的消息框', MB_ICONINFORMATION or MB_OKCANCEL);
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  dlg: TDlgTest;
begin
  SetDlgAutoClose(8*1000, True);
  dlg := TDlgTest.Create(Self);
  dlg.ShowModal;
  dlg.Free;

end;

procedure TForm1.Button5Click(Sender: TObject);
begin
  ShowMessage('Normal ShowMessage');
end;

end.