学步园

procedure TForm1.FormCreate(Sender: TObject);
begin
  Label3.Caption := '用户名: Admin' + #13 + '密码: 123';
end;

procedure TForm1.UserTxtKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if Key = 13 then
    PSWTxt.SetFocus;
end;

procedure TForm1.PSWTxtKeyDown(Sender: TObject; var Key: Word;
  Shift: TShiftState);
begin
  if Key = 13 then
  begin
    OKBtn.SetFocus;
    Exit;
  end;

  if ( Key < 48 )or ( Key > 57 ) then
    Key := 0;
end;

procedure TForm1.OKBtnClick(Sender: TObject);
begin
  if ( UserTxt.Text = 'Admin' ) and ( PSWTxt.Text = '123' ) then
    Label3.Caption := 'login successfully'
  else
  begin
    Label3.Caption := 'error!' + #13 + 'please enter again.';
  end;
end;

procedure TForm1.CancelBtnClick(Sender: TObject);
begin
  UserTxt.Text := '';
  PSWTxt.Clear;
  UserTxt.SetFocus;
  Label3.Caption := '用户名: Admin' + #13 + '密码: 123';
end;

//转自《Delphi7程序设计与开发技术大全》