Asp.Net 判断储存在xml文件中的用户名合法性(登陆操作)

XML文件请见ASP.Net中实现XMl的标识列(ID列)或自增长列
登陆按钮事件:

 private void Btn_login_Click(object sender, System.EventArgs e)
        {
            string username = this.txt_name.Text.Trim();
            string userpass = this.txt_pass.Text.Trim();
            string filename = Server.MapPath(".//XMl/User.xml");
            string str = OperateXmlByDataSet.UserLogin(filename,"username",username,"userpass",userpass);  
            Session["username"]=str;
            if(str!="sorry")
            {
                this.Lab_flag.Text=str+"登陆成功!";
             //登陆成功后的操作     }
            else
            {
                this.Lab_flag.Text="请重新登陆";
            }
        }

文中用到OperateXmlByDataSet的UserLogin方法,代码如下:

 用户登陆#region 用户登陆
        public static string UserLogin(string strXmlPath,string column1 ,string values1,string column2,string values2)
        {
            try
            {                            
                string strXsdPath = strXmlPath.Substring(0,strXmlPath.IndexOf(".")) + ".xsd";
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));
                string str="sorry";
                //先判断行数
                if(ds.Tables[0].Rows.Count > 0)
                {                    
                    for(int i=0; i< ds.Tables[0].Rows.Count; i++)
                    {
                        //如果当前记录为符合Where条件的记录
                        if(ds.Tables[0].Rows[i][column1].ToString().Trim().Equals(values1))
                        {
                            //循环给找到行的各列赋新值
                            if(ds.Tables[0].Rows[i][column2].ToString().Trim().Equals(values2))
                            {
                                str = ds.Tables[0].Rows[i][column1].ToString();
                                return str;
                            }
                            return str ;
                        }
                    }                    
                    
                }                    
                return str;
            }
            catch(Exception e)
            {
                return e.Message;
            }
        }
        #endregion