Ajax自动刷新简单示例(带xml文件传输）

调用Ajax的前台代码

        function GetData() {
            xmlHttp = window.XMLHttpRequest ? new window.XMLHttpRequest() : new ActiveXObject("MSXML2.XMLHTTP");
            var xmlDom = new ActiveXObject("MSXML2.DOMDocument");
            xmlDom.async = false;
            var xml = "<?xml version='1.0' encoding='utf-8'?><Data></Data>";
            xmlDom.loadXML(xml);
            var domRoot = xmlDom.selectSingleNode("Data");
            var node = xmlDom.createElement("Name");
       　　　node.text = “Jery”;
            domRoot.appendChild(node);
            xmlHttp.open("POST", 'RefreshHelpPage/Refresh.ashx', true);
            xmlHttp.onreadystatechange = statusChange;
            xmlHttp.setRequestHeader("Content-Type ", "application/x-www-form-urlencoded; "); 
            xmlHttp.send(xmlDom);
        }

        function statusChange() {
            if (xmlHttp.readyState == 4) {
                if (xmlHttp.status >= 200 && xmlHttp.status < 300) {
                    var json = eval(xmlHttp.responseText);
                    var name = json[0].name
                }
                else {
                }
            }
        }

        setInterval("GetData()", 5000);

被调用的一般处理程序代码

    public void ProcessRequest (HttpContext context)
    {
        context.Response.ContentType = "text/plain";
        context.Response.Expires = -1;
        context.Response.Write(JsonHelper.ObjectToJSON(getList(getXML(context))));
    }

    private static ArrayList getXML(HttpContext context)
    {
        ArrayList Names = new ArrayList();
        Stream inputStream = context.Request.InputStream;
        StreamReader reader = new StreamReader(inputStream,Encoding.UTF8);
        string xml = reader.ReadToEnd();
        
        XmlDocument xmlDoc = new System.Xml.XmlDocument();
        xmlDoc.LoadXml(xml);

        XmlElement xmlElement = xmlDoc.DocumentElement;
        for (int i = 0; i < xmlElement.ChildNodes.Count; i++)
        {
            string Name = xmlElement.ChildNodes[i].InnerText;
            Names.Add(Name);
        }

        return Names;

    }

    private List<T> getList(ArrayList Names)
    {
        
        List<T> List = new List<T>();
        try
        {
            List = getInfo(Names)//get information from bll layer
           
        }
        catch (Exception)
        {
        }
        
        return List;

    }
 
    public bool IsReusable {
        get {
            return false;
        }
    }

JSONHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Script.Serialization;

/// <summary>
/// Summary description for JsonHelper
/// </summary>
public class JsonHelper
{
    public JsonHelper()
    {
        //
        // TODO: Add constructor logic here
        //
    }

    public static string ObjectToJSON(object obj)
    {
        JavaScriptSerializer jss = new JavaScriptSerializer();
        try
        {
            return jss.Serialize(obj);
        }
        catch (Exception ex)
        {
            throw new Exception("JSONHelper.ObjectToJSON(): " + ex.Message);
        }
    }

}