ASP.Net 更新储存在xml文件中的数据(update操作)

XML文件请见ASP.Net中实现XMl的标识列(ID列)或自增长列
代码如下:
更新按钮事件:

private void Btn_update_Click(object sender, System.EventArgs e)
        {
            Xml_UpDt(ViewState["uid"].ToString());//调用Xml_UpDt方法
            BindDG();//重新绑定datagrid
        }

Xml_UpDt方法:

 void Xml_UpDt(string userid)
        {
            string username = this.Txt_name.Text;
            string userpass = this.Txt_pass.Text;
            string usermail = this.Txt_mail.Text;
            string usersite = this.Txt_site.Text;
            string usermsn = this.Txt_msn.Text;

            string [] Columns = {"username","userpass","usermail","usersite","usermsn"};
            string [] ColumnsValues = {username,userpass,usermail,usersite,usermsn};
            OperateXmlByDataSet.UpdateXmlRow(ViewState["filename"].ToString(),Columns,ColumnsValues,"userid",userid);
        }

ViewState["filename"]= Server.MapPath("..//XML//User.xml");
OperateXmlByDataSet的UpdateXmlRow方法:

 UpdateXmlRow#region UpdateXmlRow
        /**//// <summary>
        /// 更行符合条件的一条Xml记录
        /// </summary>
        /// <param name="strXmlPath">XML文件路径</param>
        /// <param name="Columns">列名数组</param>
        /// <param name="ColumnValue">列值数组</param>
        /// <param name="strWhereColumnName">条件列名</param>
        /// <param name="strWhereColumnValue">条件列值</param>
        /// <returns></returns>
        public static bool UpdateXmlRow(string strXmlPath,string[] Columns,string[] ColumnValue,string strWhereColumnName,string strWhereColumnValue)
        {
            try
            {                            
                string strXsdPath = strXmlPath.Substring(0,strXmlPath.IndexOf(".")) + ".xsd";
                DataSet ds = new DataSet();
                ds.ReadXml(GetXmlFullPath(strXmlPath));

                //先判断行数
                if(ds.Tables[0].Rows.Count > 0)
                    //                DataSet ds = new DataSet();
                    //                //读xml架构，关系到列的数据类型
                    //                ds.ReadXmlSchema(GetXmlFullPath(strXsdPath));
                    //                ds.ReadXml(GetXmlFullPath(strXmlPath));    
                    //                int count = ds.Tables[0].Rows.Count;
                    //先判断行数
                    //                if(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][strWhereColumnName].ToString().Trim().Equals(strWhereColumnValue))
                        {
                            //循环给找到行的各列赋新值
                            for(int j=0; j < Columns.Length; j++)
                            {                                                            
                                ds.Tables[0].Rows[i][Columns[j]] = ColumnValue[j];                                
                            }
                            //更新DataSet
                            ds.AcceptChanges();
                            //重新写入XML文件
                            ds.WriteXml(GetXmlFullPath(strXmlPath));
                            return true;
                        }
                    }                    
                    
                }                    
                return false;
            }
            catch(Exception)
            {
                return false;
            }
        }
        #endregion