AJAX聊天室小DEMO(讨厌JS,IE下有问题已解决)

太闲啦,太闲啦,连续一月没上课了.不知他们想我没.昨QQ上一JJ给我看她写的聊天室,刷的眼难受,让我帮她写个不刷新的给她看.就是闲嘛,一切都是Teach Myself,从来没人指导过我.想帮帮她.偶尔有个人帮我我也很感动.顺便自个学点东西吧.一直没用在CNBLOGS上东西,上次发错了,发到首页上去了,写的一个数据结构的代码片断,一大哥骂我不写注释,原来首页就是那个意思,现在我没事就往首页上发,旨在寻人骂我.我是菜鸟我怕谁,PS:在此之前我只懂点AJAX原理,对框架一无所知.以下是DEMO.发上来主要是给大家批评的还有点问题想请教.
我用XML做一个队列类似的东西存储10条信息.先入先出.再用ajax取出信息反应到聊天窗口,聊天窗口1秒刷一次
default.aspx页 表单部分

<div id="div_chat" class="chat">

</div>

<input type="text" id="userName" name="userName" value="annoymous">
<!-- 输入消息的文本框-->
<input type="text" id="txt_message" name="txt_message" class="textInput" size="80" /> 
<!-- 点击提交按钮时调用sendChatText()方法发送消息-->
<input type="button" name="btn_send_chat" id="btn_send_chat" value="Send" class="normalButton" onclick="javascript:sendChatText();" />

下面是ajax_chat.js代码

            var sendReq = createAjaxObj();
            var receiveReq = createAjaxObj();
            var mTimer;
            var lastMessage = 0;  //最后一条Message ID值
            var n_messages=0;  //XML中的MESSAGE节点数,我设的是10条
            var diff=0;
            var chat_div = document.getElementById('div_chat');
            function startChat()
             {
             var content=document.getElementById('div_chat');  
                document.getElementById('txt_message').focus();
                 //为什么我直接用chat_div不行,非要重定义一个content变量才行?晕哦.
                  content.innerHTML="<font color=red>Solo's chatroom demo,chang u name first!</font><br/>";
                //每隔2秒执行一次取文本的命令
                setInterval("getChatText()",1000);
                
            }        
function createAjaxObj()
{
//创建兼容的的xmlhttp对象
    var xmlhttp;
     try
        {
        xmlhttp=new ActiveObject('Msxml2.XMLHTTP');
        }
        catch(e)
        {
            try
            {
            xmlhttp=new ActiveObject('Microsoft.XMLHTTP');
            }
            catch(e)
            {
                try
                {
                xmlhttp=new XMLHttpRequest();
                }
                catch(e){}
            }
        }
       return xmlhttp;
}
//获取XML文本
function getChatText() 
{

//判断上次请求的状态是否完成或是还未发送请求
    if (receiveReq.readyState == 4 || receiveReq.readyState == 0) {
        //从content.xml获取聊天内容
    receiveReq.open("get","content.xml");
    //当请求状态改变时调用handleReceiveChat方法
        receiveReq.onreadystatechange = handleReceiveChat; 
        receiveReq.send(null);//因为是get方法所以发送请求null
    }            
}
function handleReceiveChat() 
{

    if (receiveReq.readyState == 4)
     {//此时请求已经完成
       //获得显示消息的图曾层元素
        var chat_div = document.getElementById('div_chat');
        //获得返回后的XML文件
        var xmldoc = receiveReq.responseXML;
        //得到所有的新的消息记录
        var message_nodes = xmldoc.getElementsByTagName("message"); 
        n_messages = message_nodes.length;
        

        var id=message_nodes[n_messages-1].getAttribute("id");
        lastMessage=getCookie("lastMessage");
        if(lastMessage==null)
        {
            addCookie("lastMessage","0",10);
            lastMessage=getCookie("lastMessage");
         }
         
         if(id-lastMessage>=n_messages)
         {
          var i=0;
            diff=n_messages;
            while((message_nodes[n_messages-1].getAttribute("id")>=lastMessage)&&i<=diff-1)
            {
                var user_node = message_nodes[i].getElementsByTagName("user");
                var text_node = message_nodes[i].getElementsByTagName("text");
                var time_node = message_nodes[i].getElementsByTagName("time");
                chat_div.innerHTML += '(<font class="chatUser">'+user_node[0].firstChild.nodeValue + '</font>)&nbsp;said at &nbsp;';
                chat_div.innerHTML += '<font class="chatTime">' + time_node[0].firstChild.nodeValue + '</font><br />';
                chat_div.innerHTML += '<span class="title">'+text_node[0].firstChild.nodeValue + '</span><br />';
                chat_div.scrollTop = chat_div.scrollHeight;
                //每循环一条消息，记录到id到,lastMessage的cookie中        
                lastMessage = (message_nodes[i].getAttribute("id"));
                deleteCookie("lastMessage");
                addCookie("lastMessage",lastMessage,5);
                
                 i++;
              // alert("this lastMessage:"+lastMessage);    
                 
            }
         }
         else
         {
            while(message_nodes[n_messages-1].getAttribute("id")>lastMessage)
            {
                var dif=message_nodes[n_messages-1].getAttribute("id")-lastMessage;
                var temp=n_messages-dif;
                if(dif!=0)
                {
                var user_node = message_nodes[temp].getElementsByTagName("user");
                var text_node = message_nodes[temp].getElementsByTagName("text");
                var time_node = message_nodes[temp].getElementsByTagName("time");
                chat_div.innerHTML += '(<font class="chatUser">'+user_node[0].firstChild.nodeValue + '</font>)&nbsp;said at &nbsp;';
                chat_div.innerHTML += '<font class="chatTime">' + time_node[0].firstChild.nodeValue + '</font><br />';
                chat_div.innerHTML += '<span class="title">'+text_node[0].firstChild.nodeValue + '</span><br />';
                chat_div.scrollTop = chat_div.scrollHeight;
                //每循环一条消息，记录到全局变量lastMessage的Cookie中        
          
                deleteCookie("lastMessage");
                 lastMessage++;
                addCookie("lastMessage",lastMessage,1);
               
                temp++;
                }
              
               //alert("this lastMessage:"+lastMessage+"getAttribute:"+message_nodes[n_messages-1].getAttribute("id"));    
                 
            }
         }
         
       
    }
}
//发送聊天内容
function sendChatText()
 {
       if(document.getElementById('userName').value=='annoymous')
       {
            alert("Input your name!");
            return;
       }
//如果输入的消息为空，提示用户输入
    if(document.getElementById('txt_message').value == '')
     {
        alert("You have not entered a message");
        return;
    }
    //判断上次发送消息请求的状态是否完成或是还未发送请求
    if (sendReq.readyState == 4 || sendReq.readyState == 0) 
    {
       //保存消息的服务器地址
        var submitURL = "sendMessage.aspx?userName="+document.getElementById('userName').value+"&msg="+document.getElementById('txt_message').value;
        sendReq.open("POST",  submitURL , true);//建立请求连接
        sendReq.setRequestHeader('Content-Type','application/x-www-form-urlencoded');
        sendReq.onreadystatechange = handleSendChat; //当请求状态改变时调用handleSendChat方法
        sendReq.send(null);//发送请求
       
        document.getElementById('txt_message').value = '';//设置提交消息文本框为空
      
    }                            
}
function handleSendChat()
 {
 //发送后强制执行一次获取聊天内容一次

    //lastMessage =getCookie("lastMessage");
    getChatText();
}

//三个JS常用的函数网上抄的
function addCookie(name,value,expireMin)
{
    var cookieString=name+"="+escape(value);
    //判断是否设置过期时间
    if(expireMin>0){
        var date=new Date();
        date.setTime(date.getTime+expireMin*60*1000);
        cookieString=cookieString+"; expire="+date.toGMTString();
    }
    document.cookie=cookieString;
}
function getCookie(name)
{
//获取指定名称的Cookie值
    var strCookie=document.cookie;
    var arrCookie=strCookie.split(";");
    for(var i=0;i<arrCookie.length;i++)
    {
        var arr=arrCookie[i].split("=");
        if(arr[0]==name)
        return arr[1];
    }
    return null;
}
  function deleteCookie(name)
  {
     var expires=new Date();
     expires.setTime(expires.getTime()-1);
     addCookie(name,"Delete Cookie",expires);
   }

点击发送 sendMessage.aspx

public partial class sendMessage : System.Web.UI.Page
{
    XmlDocument doc;
    string filePath; //聊天内容存储的XML文件
    protected void Page_Load(object sender, EventArgs e)
    {
        filePath = Server.MapPath("content.xml");
        doc = new XmlDocument();
        doc.Load(filePath);
        if (!IsPostBack)
        {
            if (Application["lock"].ToString() == "unlock")
             {
                Application["lock"] = "lock"; //锁定防止多用户操作
                int num = GetLastMsgId();
                num++;
                string msgid = num.ToString();

                if (Request.QueryString["userName"] != string.Empty && Request.QueryString["msg"] != string.Empty)
                {
                    if (GetMsgNum() < 10)
                    {
                        //如果消息少于10条,添加结点
                        AddInLast(msgid, Request.QueryString["userName"].Trim(), Request.QueryString["msg"].Trim());
                    }
                    else
                    {
                        //如果消息少于10条,弹出第一条,再向末结点后添加结点
                        DelFirst();
                        AddInLast(msgid, Request.QueryString["userName"].Trim(), Request.QueryString["msg"].Trim());
                    }
                    
                }
                Application["lock"] = "unlock"; //解锁
            }
        }
        doc = null;
    }
    public void DelFirst()
    {
        //如果超过10条弹出第一条
        XmlNode node = doc.DocumentElement;
       
        node.RemoveChild(node.FirstChild);
    }
    public int GetMsgNum()
    {
        //Message数目
        XmlNode node = doc.DocumentElement;
        return node.ChildNodes.Count;
    }
    public int GetLastMsgId()
    {
        //最后一条ID
        XmlNode node = doc.DocumentElement;
        XmlElement last = (XmlElement)node.LastChild;
        return Convert.ToInt32(last.GetAttribute("id"));
    }
    public void AddInLast(string id,string strUser,string strContent)
    {
        //加入新建Messag结点
        XmlNode node = doc.DocumentElement;
        XmlElement msgNode = doc.CreateElement("message");
        msgNode.SetAttribute("id",id);
        node.AppendChild(msgNode);


        XmlElement eleUser = doc.CreateElement("user");
        XmlText textUser = doc.CreateTextNode(strUser);
        eleUser.AppendChild(textUser);
        msgNode.AppendChild(eleUser);

        XmlElement eleContent = doc.CreateElement("text");
        XmlText textText = doc.CreateTextNode(strContent);
        eleContent.AppendChild(textText);
        msgNode.AppendChild(eleContent);

        XmlElement eleTime = doc.CreateElement("time");
        XmlText textTime = doc.CreateTextNode(DateTime.Now.ToString());
        eleTime.AppendChild(textTime);
        msgNode.AppendChild(eleTime);

        doc.Save(filePath);

    }
}

content.xml结构:

<?xml version="1.0" encoding="utf-8"?>
<root>

  <message id="125">
    <user>test</user>
    <text>test</text>
    <time>2006-12-23 16:06:07</time>
  </message>
</root>

解决方案:/Files/fancystyle/chat.rar