unit1.pas

DELPHI经典程序

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
  var
   MessAnswer:Integer;
begin
  MessAnswer:=Application.MessageBox('这样系统会关闭哦！','警告'
    ,MB_TOPMOST+MB_ICONWARNING+MB_OKCANCEL+MB_DEFBUTTON2);
  case MessAnswer of
    IDOK: CanClose := True ;
    IDCANCEL: CanClose := False ;
  end;

end;

end.