在Asp.net中使用DOM對象操作XML

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
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.XML;

public partial class ReadWriteConfig : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!this.IsPostBack)
        {
            Read();
        }
    }

    private void Read()
    {
        string filename = Server.MapPath("") + @"\App_Data\webconfig.XML";
        XmlDocument xmldoc = new XMLDocument();
        XMLdoc.Load(filename);

        XmlNodeList topM = XMLdoc.DocumentElement.ChildNodes;//獲取與aPPSettings同級的結點
        foreach (XMLElement element in topM)
        {
            if (element.Name == "aPPSettings")
            {
                XMLNodeList node = element.ChildNodes;
                if (node.Count > 0)
                {
                    DropDownList1.Items.Clear();
                    foreach (XMLElement el in node)
       &