Read and Write XML

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Data.SqlClient;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;    //this
using System.Text; //this
using System.Xml;  //this

 

    /// <summary>
    /// 生成XML文件
    /// </summary>
    private void writeXml()
    {
        try
        {
            string strName = Guid.NewGuid().ToString().Replace("-","");

            Session["filename"] = "Read" + strName + ".xml";

            string sFilePath = Server.MapPath("../TempFiles/" + Session["filename"].ToString());

            XmlTextWriter writer = new XmlTextWriter(sFilePath, Encoding.UTF8);
            writer.WriteStartDocument();
            writer.WriteStartElement("INPUT");
            writer.WriteStartElement("TextBox");
            foreach (Control ctl in form1.Controls)
            {
                if (ctl.GetType().Name == "TextBox")
                {
                    TextBox tb = new TextBox();
                    tb = (TextBox)this.FindControl(ctl.ID);
                    writer.WriteElementString(tb.ID, tb.Text);
                }
                else if (ctl.GetType().Name == "DropDownList")
                {
                    DropDownList tb = new DropDownList();
                    tb = (DropDownList)this.FindControl(ctl.ID);
                    writer.WriteElementString(tb.ID, tb.SelectedItem.Text);
                }
            }
            writer.WriteEndElement();
            writer.WriteEndDocument();
            writer.Close();
        }
        catch (Exception ex)
        {
            throw ex;
        }
    }
   
   
   
    private void loadXml(string strFileName)
    {
        DataSet mydds = new DataSet();

        string sFilePath = Server.MapPath("../TempFiles/" + strFileName);

        //Session.Remove("filename");

        if (File.Exists(sFilePath))
        {
            mydds.ReadXml(sFilePath);

            for (int i = 0; i < mydds.Tables[0].Columns.Count; i++)
            {
                try
                {
                    TextBox tbx = new TextBox();
                    tbx = (TextBox)this.FindControl(mydds.Tables[0].Columns[i].ColumnName);
                    tbx.Text = mydds.Tables[0].Rows[0][i] + "";
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
        }
        else
        {
            Session.Remove("filename");
            throw new Exception("Custm");
        }

    }