关于登陆界面的验证。初学者
代码

  public bool ValidateUser(string txtUser,string txtPwd,ref string message )
        {
          
            
          string sql = string.Format("SELECT COUNT(*) FROM User WHERE ID='{0}'AND Pwd='{1}'",txtUser   , txtPwd );


            try
            {
               // 创建command命令
                SqlCommand command = new SqlCommand(sql, DBHekper.connetion);
                DBHekper.connetion.Open();
                int count = (int)command.ExecuteNonQuery();//统计返回值
                if (count ==1)
                {
                    return  true;
                }
                else
                {
                    message = "用户名或密码不存在！";
                     return  false;;
                }

            }
            catch (Exception ex)
            {
                 message = "操作数据库出错";
                    Console.WriteLine(ex.Message);
                    
            }

           
            finally
            {
               DBHekper.connetion.Close();
               

            }
            return false;
           &nb