/// <summary>
 /// 通过账号和密码验证用户是否存在,存在返回true运行登录,否则拒绝登录
 /// </summary>
 /// <param name="account"></param>
 /// <param name="passWord"></param>
 /// <returns></returns>
 public bool landing(string account, string passWord)
 {
     return(db.userExist(account, passWord));
 }