DropDownList多级树

DropDownList多级树
Cate.xml文件内容

<?xml version="1.0" encoding="utf-8" ?>
<Root>
  <Content>
    <ID>1</ID>
    <ParentID>0</ParentID>
    <CateName>类别1</CateName>
  </Content>
  <Content>
    <ID>2</ID>
    <ParentID>1</ParentID>
    <CateName>类别2</CateName>
  </Content>
  <Content>
    <ID>3</ID>
    <ParentID>2</ParentID>
    <CateName>类别3</CateName>
  </Content>
  <Content>
    <ID>4</ID>
    <ParentID>3</ParentID>
    <CateName>类别4</CateName>
  </Content>
  <Content>
    <ID>5</ID>
    <ParentID>0</ParentID>
    <CateName>类别5</CateName>
  </Content>
  <Content>
    <ID>6</ID>
    <ParentID>0</ParentID>
    <CateName>类别6</CateName>
  </Content>
  <Content>
    <ID>7</ID>
    <ParentID>6</ParentID>
    <CateName>类别7</CateName>
  </Content>
  <Content>
    <ID>8</ID>
    <ParentID>7</ParentID>
    <CateName>类别8</CateName>
  </Content>
  <Content>
    <ID>9</ID>
    <ParentID>0</ParentID>
    <CateName>类别9</CateName>
  </Content>
  <Content>
    <ID>10</ID>
    <ParentID>0</ParentID>
    <CateName>类别10</CateName>
  </Content>
</Root>

面页Default.aspx内容

Default.aspx.cs内容

using System;
using System.Data;
using System.Configuration;
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;

public partial class _Default : System.Web.UI.Page 

App_Code/CateDAL.cs文件

using System;
using System.Data;
using System.Configuration;
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;

XmlUtility.cs文件就是介绍我的博客上有