无限极列表2

Code：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace WebAppFL
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
                BindDropDownList(this.AreaSource);
        }
        /// <summary>
        /// 绑定分类下拉列表
        /// </summary>
        private void BindDropDownList(List<TreeType> myList)
        {
            this.TParentCate.Items.Add(new ListItem("◇根目录", "0"));
            BindDropListByList(myList);

        }


        /// <summary>
        /// List<T>里过滤根基点
        /// </summary>
        /// <param name="m">结构树</param>
        /// <returns>T/F</returns>
        private bool FindMatch(TreeType m)
        {
            if (m.ParentID == 0)
            {
                return true;
            }
            return false;
        }

        /// <summary>
        /// 按层次绑定下拉框
        /// </summary>
        /// <param name="mList">结构树</param>
        private void BindDropListByList(List<TreeType> mList)
        {
            string chrFlag = "┆┄◇";
            List<TreeType> list = mList.FindAll(FindMatch);
            foreach (TreeType m in list)
            {
                this.TParentCate.Items.Add(new ListItem(chrFlag + m.Name, m.ID.ToString()));
                RecursionBind(mList, m.ID, ref chrFlag);
            }
        }
        /// <summary>
        /// 绑定类
        /// </summary>
        /// <param name="mList">结构树</param>
        /// <param name="mCateID">树编号</param>
        /// <param name="chr">分割符</param>
        private void RecursionBind(List<TreeType> mList, int mCateID, ref string chr)
        {
            foreach (TreeType m in mList)
            {
                if (m.ParentID == mCateID)
                {
                    chr = "┆┄" + chr;
                    this.TParentCate.Items.Add(new ListItem(chr + m.Name, m.ID.ToString()));
                    RecursionBind(mList, m.ID, ref chr);
                }

            }
            if (chr != "┆┄◇")
            chr = chr.Remove(0,2);

        }

        /// <summary>
        /// 测试数据源
        /// </summary>
        private List<TreeType> AreaSource
        {
            get
            {
                List<TreeType> TreeList = new List<TreeType>();
                TreeList.Add(new TreeType(1, 0, "湖北"));
                TreeList.Add(new TreeType(2, 0, "江苏"));
                TreeList.Add(new TreeType(3, 0, "浙江"));
                TreeList.Add(new TreeType(4, 1, "黄冈"));
                TreeList.Add(new TreeType(5, 4, "黄冈镇级"));
                TreeList.Add(new TreeType(6, 5, "黄冈村"));
                TreeList.Add(new TreeType(7, 3, "杭州"));
                TreeList.Add(new TreeType(8, 2, "南京"));
                TreeList.Add(new TreeType(9, 0, "北京"));
                TreeList.Add(new TreeType(10, 9, "海淀"));
                TreeList.Add(new TreeType(11, 10, "中关村"));
                TreeList.Add(new TreeType(12, 10, "上地"));
                return TreeList;
            }
        }


    }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace WebAppFL
{
    public class TreeType
    {
        private int  _ID;
        public int ID
        {
            get { return _ID; }
            set { _ID = value; }
        }
        private string _Name;
        public string Name
        {
            get { return _Name; }
            set { _Name = value; }
        }
        private int _ParentID;
        public int ParentID
        {
            get { return _ParentID; }
            set { _ParentID = value; }
        }
        public TreeType(int id, int parentid, string name)
        {
            // TODO: Complete member initialization
            this._ID = id;
            this._Name = name;
            this._ParentID = parentid;
           
        }
    }
}

HTML：

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebAppFL.WebForm1" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
     <asp:DropDownList ID="TParentCate" runat="server"></asp:DropDownList>
    </div>
    </form>
</body>
</html>

demo：