unit1.pas

本光盘是《Delphi 7应用教程》一书的配套光盘

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Label1: TLabel;
    Edit1: TEdit;
    Label2: TLabel;
    Edit2: TEdit;
    procedure Edit1KeyPress(Sender: TObject; var Key: Char);
    procedure Edit2KeyPress(Sender: TObject; var Key: Char);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
  if ord(key)=13 then //如果是回车键
      if  edit1.text<>'123456'  then//如果账号不正确
          begin
             ShowMessage('账号有错误，请重新输入');//显示提示信息
             edit1.text:='';
             edit1.setFocus;
          end
      else
         Edit2.SetFocus //把焦点移至Edit2，以便输入密码
  else
    if (key<'0') or (key>'9') then//如果输入的不是数字
       begin
            Showmessage('账号必须为数字'); //显示提示信息
            key:=#0; //清除输入的字符
       end;
 end;

procedure TForm1.Edit2KeyPress(Sender: TObject; var Key: Char);
begin
  if ord(key)=13 then  //如果是回车键
    if edit2.text='Pass'  then //如果密码正确
       begin
          ShowMessage('欢迎你使用本系统！');//进入系统提示
          Form1.Close ; //关闭窗体
       end
    else  //密码输入不正确
       begin
          ShowMessage('密码错误，请重新输入！'); //提示密码错
          Edit2.text:='';
          edit2.SetFocus ;
       end;
end;

end.