AJAX聊天室小DEMO(讨厌JS,IE下有问题已解决)

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
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="Solo's chatroom demo,chang u name first! ";
 //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 += '('+user_node[0].firstChild.nodeValue + ') said at  ';
 chat_div.innerHTML += '' + time_node[0].firstChild.nodeValue + ' ';
 chat_div.innerHTML += ''+text_node[0].firstChild.nodeValue + ' ';
 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 += '('+user_node[0].firstChild.nodeValue + ') said at  ';
 chat_div.innerHTML += '' + time_node[0].firstChild.nodeValue + ' ';
 chat_div.innerHTML += ''+text_node[0].firstChild.nodeValue + ' ';
 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
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原文地址：https://www.cnblogs.com/solo/p/601669.html