ASP.NET2.0 TreeView动态加载问题

aspx页面内容如下:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default3.aspx.cs" Inherits="Default3"%>

<!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 id="Head1" runat="server">
    <title>Untitled Page</title>
</head>

<body bgcolor="white">
    <form id="form1" runat="server">
    <div>
    <asp:treeview ID="Treeview1" runat="server" ImageSet="XPFileExplorer" AutoGenerateDataBindings="false" ExpandDepth="0"
        OnTreeNodePopulate="Treeview1_TreeNodePopulate" ShowLines="True"
    >
        <SelectedNodeStyle BackColor="#B5B5B5"></SelectedNodeStyle>
        <Nodes>
            <asp:TreeNode Value="0" Text="C:" PopulateOnDemand="True">
            </asp:TreeNode>
        </Nodes>
        <NodeStyle VerticalPadding="2px" Font-Names="Tahoma" Font-Size="8pt" HorizontalPadding="2px"
            ForeColor="Black"></NodeStyle>
        <HoverNodeStyle Font-Underline="True" ForeColor="#6666AA"></HoverNodeStyle>
    </asp:treeview>
    </div>
    </form>
</body>
</html>

cs 文件:
using System;
using System.IO;
using System.Data;
using System.Data.SqlClient;
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;

public partial class Default3 : System.Web.UI.Page
{

    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Treeview1_TreeNodePopulate(object sender, TreeNodeEventArgs e)
    {
        if (IsCallback)
            if (e.Node.ChildNodes.Count == 0)
            {
                Response.Write(e.Node.Value);
                LoadChildNode(e.Node);
                //Response.Write("<script language='javascript'>alert('" + e.Node.Value.ToString() + "');</script>");
            }

    }
    private void LoadChildNode(TreeNode node)
    {
        #region test

        string connectionString = ConfigurationManager.ConnectionStrings["ece_libConnectionString"].ConnectionString;
        SqlConnection con = new SqlConnection(connectionString);
        con.Open();
        SqlDataAdapter sda = new SqlDataAdapter("select * from leo_proclass where ClassID<>50 and parentid=" +node.Value.Trim(), con);
        DataSet ds = new DataSet();
        sda.Fill(ds, "dir");
        foreach (DataRow dr in ds.Tables["dir"].Rows)//目录节点
        {
            TreeNode newNode = new TreeNode();
            item info = new item(dr["ClassID"].ToString());//根据节点的value值创建目录
            if (info.flag())
            {
                newNode.PopulateOnDemand = true;//节点允许被展开
                newNode.SelectAction = TreeNodeSelectAction.SelectExpand;

            }
            else
            {
                newNode.PopulateOnDemand = false;//节点不允许被展开

            }

            newNode.Text = dr["ClassName"].ToString() + dr["ClassID"].ToString(); ;
            newNode.Value = dr["ClassID"].ToString().Trim();//节点的完整路径名
            node.ChildNodes.Add(newNode);//添加目录节点
        }

        con.Close();
        #endregion
}

运行之后出现"Input string was not in a correct format"
实在解决不了!! --------------------编程问答--------------------
   学习！！
我正要这样的DEMO，可以发份吗``
     guohua2208@163.com --------------------编程问答-------------------- up --------------------编程问答-------------------- 遇到了同样的问题,我用treeview绑定.sitemap文件,在点击节点的时候就出现了这样的问题,本机测试没问题,放在服务器上就出现了这样的问题..
关注一下 --------------------编程问答-------------------- 我的问题解决!
我在web.config 中加了一句
<globalization fileEncoding="utf-8" requestEncoding="utf-8" responseEncoding="utf-8"/>
与.sitemap中的保持一致就OK了!

补充：.NET技术 ,  ASP.NET