unit1.pas

delphi编制的简单系统登录程序。解压即可用。

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Edit1: TEdit;
    Button1: TButton;
    Label1: TLabel;   //登陆按钮
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

var
    Count : integer = 1;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if Edit1.Text = 'aaaa' then //假设正确密码是aaaa
    self.ModalResult := mrOK
  else begin
    if Count>2 then begin
      Showmessage('连续三次错误, 程序退出.');
      self.ModalResult := mrCancel;
      exit;
    end;
    Inc(Count);
    Showmessage('密码错误, 请重新输入!');
    Edit1.Clear;
    Edit1.SetFocus;
  end;
end;
end.