delphi界面登陆功能代码实现，散分

(*---------------登录的方法，用于封装---------------*)
function TBookMngFrm.LoginReader : boolean;
var
  str ,readerID, pwd: string;
  LreaderID, Lpwd: Integer;
begin
  readerID := trim(readerIDEdit.text);
  pwd := trim(pwdEdit.Text);
  LreaderID := Length(readerID);
  Lpwd := Length(pwd);
  if readerID='' then showmessage('请输入用户名') else
if pwd='' then showmessage('请输入密码')

else
  
begin

  adoquery1.Close;                                   //先关，清空，
  adoquery1.SQL.Clear;                               //把SQL语句放进去，打开再执行
  adoquery1.SQL.Text:='select * from readers where readerID='
                      +readerID+' and pasword='+pwd+'';
  adoquery1.Open ;
  if adoquery1.RecordCount = 0  then
    begin
    Application.MessageBox('用户名或密码不正确！请重新输入！','注意！',MB_OK);
    readerIDEdit.Text :='';
    pwdEdit.Text :='';
   end
 else
  begin
    labelID.Visible := false;             //设置登陆界面隐藏
    readerIDEdit.Visible :=false;
    labelpwd.visible := false;
    pwdedit.visible := false;
    loginbttn.Visible := false;

    str := adoquery1.FieldByName('readername').AsString;
    label5.Caption := str + '：你好！';
  end
end;
end;