使用XMLHTTP实现联动菜单，可是无法显示数据

var oHttpReq = new ActiveXObject("Microsoft.XMLHTTP");
var oDoc = new ActiveXObject("Microsoft.XMLDOM");
oHttpReq.open("POST", "NodeData1.aspx?id="+ClassID, false); //调用读取小类数据的页面，将大类编号值传递过去
oHttpReq.send("");
result = oHttpReq.responseText;
oDoc.loadXML(result);
items = oDoc.selectNodes("//NewDataSet/Table/title"); //读取所有请求大类所属小类的名称
alert(items[0]);用alert查看数据是空的，但NodeData1.aspx页面查询后生成的XML是有数据的

解决方案 »

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我找的一个，drpdlstNoFresh.aspx文件内容：<%@ Page language="c#" Codebehind="drpdlstNoFresh.aspx.cs" AutoEventWireup="false" Inherits="localhost.duo.drpdlstNoFresh" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>drpdlstNoFresh</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
<script>
function load(state){
var drp2 = document.getElementById("DropDownList2");
for(var i = 0;i<=drp2.options.length -1;i++){
drp2.remove(i);
}
var oHttpReq = new ActiveXObject("MSXML2.XMLHTTP");
var oDoc = new ActiveXObject("MSXML2.DOMDocument");
oHttpReq.open("POST", "drpdlstnofresh1.aspx?state="+state, false);
oHttpReq.send("");
result = oHttpReq.responseText;
oDoc.loadXML(result);
items = oDoc.selectNodes("//CITY/Table");
for (var item = items.nextNode(); item; item = items.nextNode()){
var city = item.selectSingleNode("//city").nodeTypedValue;
var newOption = document.createElement("OPTION");
newOption.text = city;
newOption.value = city;
drp2.options.add(newOption);
}
}
</script>
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList>
<asp:DropDownList id="DropDownList2" runat="server"></asp:DropDownList>
</form>
</body>
</HTML>drpdlstNoFresh.aspx.cs文件内容：using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;namespace localhost.duo
{
/// <summary>
/// drpdlstNoFresh 的摘要说明。
/// </summary>
public class drpdlstNoFresh : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DropDownList DropDownList1;
protected System.Web.UI.WebControls.DropDownList DropDownList2;

private void Page_Load(object sender, System.EventArgs e)
{
SqlConnection con = new SqlConnection("server=localhost;database=pubs;uid=sa;pwd=;");
SqlDataAdapter da = new SqlDataAdapter("select state from authors group by state",con);
DataSet ds = new DataSet();
da.Fill(ds);
this.DropDownList1.DataSource=ds;
this.DropDownList1.DataTextField = "State";
this.DropDownList1.DataValueField = "State";
this.DropDownList1.DataBind();
this.DropDownList1.Attributes.Add("onchange","load(this.options[this.selectedIndex].innerText)");
} #region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load); }
#endregion
}
}
drpdlstnofresh1.aspx.cs内容：using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Xml;namespace localhost.duo
{
/// <summary>
/// drpdlstnofresh1 的摘要说明。
/// </summary>
public class drpdlstnofresh1 : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
if(this.Request["state"]!=null)
{
string state = this.Request["state"].ToString();
SqlConnection con = new SqlConnection("server=localhost;database=pubs;uid=sa;pwd=;");
SqlDataAdapter da = new SqlDataAdapter("select city from authors where state = '"+state+"'",con);
DataSet ds = new DataSet("CITY");
da.Fill(ds);
XmlTextWriter writer = new XmlTextWriter(Response.OutputStream, Response.ContentEncoding);
writer.Formatting = Formatting.Indented;
writer.Indentation = 4;
writer.IndentChar = ' ';
ds.WriteXml(writer);
writer.Flush();
Response.End();
writer.Close();
}
} #region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load); }
#endregion
}
}
我用的就是这个方法，但oHttpReq.responseText返回的结果项中子节点没有数据
result = oHttpReq.responseText;
改一下
result = oHttpReq.responseXML;
result = oHttpReq.responseText;
oDoc.loadXML(result);
result返回的是xml格式的才可以这样用，不是xml格式的loadXML不会成功的
还有一种方法。
oDoc.load(url);这样也行不要xmlhttp
查看result返回的结果，读出来的只有结构
<name>
    <Table>
        <title></title>
    </Table>
</name>
为什么没有读出数据呢？
把你的NodeData1.aspx文件的原码让我看看
if(this.Request["id"]!=null)
{
string id = this.Request["id"].ToString();
string sql="select title from 目录树表 where parent='"+id+"'";SqlDataAdapter da = new SqlDataAdapter(sql,control.objConnection);
DataSet ds = new DataSet("name");
da.Fill(ds);
XmlTextWriter writer = new XmlTextWriter(Response.OutputStream, Response.ContentEncoding);
writer.Formatting = Formatting.Indented;
writer.Indentation = 4;
writer.IndentChar = ' ';
ds.WriteXml(writer);
writer.Flush();
writer.Close();
Response.End();
}
我对XML不是很了解，请大家帮忙指点
问题解决了，是XML编码的问题