C#制作简单的多人在线即时交流聊天室
实现网页版的在线聊天室的方法有很多,在没有来到HTML5之前,常见的有:定时轮询、长连接+长轮询、基于第三方插件(如FLASH的Socket),而如果是HTML5,则比较简单,可以直接使用WebSocket,当然HTML5目前在PC端并没有被所有浏览器支持,所以我的这个聊天室仍是基于长连接+长轮询+原生的JS及AJAX实现的多人在线即时交流聊天室,这个聊天室其实是我上周周末完成的,功能简单,可能有些不足,但可以满足在线即时聊天需求,分享也是给大家提供一个思路,大家可以基于此来实现更好的在线即时聊天工具。
聊天室功能简介:
1。支持多人进入同一个聊天室聊天;
2。进入即离线均会自动生成通知信息显示在聊天室中,这样聊天的人们就知道谁进来了谁离开了;
3。实时显示在线人员表列;
4。无需数据库支持,全部存在内存中,当然有条件的可以采用分布式缓存或加一个数据库来存,这里演示就是用内存来存了。
下面就开始分享我的代码,由于采用原生的JS及AJAX,所以简单易懂,代码分别WEB前端及服务端(有点废话了)
WEB前端源代码如下:(ChatPage.html)
<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title></title> <style type="text/css"> html, body { margin: 0px; padding: 0px; width: 100%; height: 100%; background-color: #f8f7f7; font-family: arial,sans-serif; } #layouttable { margin:0px; padding:0px; width:100%; height:100%; border:2px solid green; border-collapse:collapse; min-width:800px; } #layouttable td { border: 1px solid green; } .h100p { height:100%; } .midtr{height:auto;} .midtr tr td { height: 100%; } #chatmsgbox, #chatonlinebox { background-color:white; overflow-x: hidden; overflow-y: auto; overflow-wrap: break-word; height: 100%; } #chatonlinebox { background-color:#f5d0a8; } .rc, .sd { overflow:hidden; } .rc p { float: left; color: green; } .sd p { float: right; color: orange; } </style> </head> <body> <table id="layouttable"> <colgroup> <col style="width:auto" /> <col style="width: 200px;" /> </colgroup> <tr style="height:30px; background-color:lightblue;color:yellow;"> <td> 欢迎进入梦在旅途的网页即时在线大众聊天室 - www.zuowenjun.cn: </td> <td> 当前在线人员 </td> </tr> <tr style="height:auto;" id="midtr"> <td> <div id="chatmsgbox"> </div> </td> <td> <div id="chatonlinebox"> <ul id="chatnames"></ul> </div> </td> </tr> <tr style="height:50px;"> <td colspan="2"> <label for="name">聊天妮称:</label> <input type="text" id="name" style="width:80px;" /> <input type="button" id="btnsavename" value="确认进入" /> <label for="msg">输入内容:</label> <input type="text" id="msg" style="width:400px;" /> <input type="button" id="btnSend" value="发送消息" disabled="disabled" /> </td> </tr> </table> <script type="text/javascript"> var chatName = null; var oChatmsgbox, oMsg, oChatnames; var ajaxforSend, ajaxforRecv; //页面加载初始化 window.onload = function () { document.getElementById("btnsavename").onclick = function () { this.disabled = true; var oName = document.getElementById("name"); oName.readOnly = true; document.getElementById("btnSend").disabled = false; //receiveMsg(); setChatStatus(oName.value,"on"); } document.getElementById("btnSend").onclick = function () { sendMsg(oMsg.value); }; //init oChatmsgbox = document.getElementById("chatmsgbox"); oMsg = document.getElementById("msg"); oChatnames = document.getElementById("chatnames"); ajaxforSend = getAjaxObject(); ajaxforRecv = getAjaxObject(); } //离开时提醒 window.onbeforeunload = function () { event.returnValue = "您确定要退出聊天室吗?"; } //关闭时离线 window.onunload = function () { setChatStatus(chatName, "off"); } //设置聊天状态:在线 OR 离线 function setChatStatus(name, status) { callAjax(getAjaxObject(), "action=" + status + "&name=" + name, function (rs) { if (!rs.success) { alert(rs.info); return; } if (status == "on") { chatName = document.getElementById("name").value; setTimeout("receiveMsg()",500); } loadOnlineChatNames(); }); } //加载在线人员名称列表 function loadOnlineChatNames(){ callAjax(getAjaxObject(), "action=onlines", function (rs) { var lis = ""; for(var i=0;i<rs.length;i++) { lis += "<li>"+ rs[i] +"</li>"; } oChatnames.innerHTML = lis; }); } //接收消息列表 function receiveMsg() { callAjax(ajaxforRecv, "action=receive&name=" + chatName, function (rs) { if (rs.success) { showChatMsgs(rs.msgs, "rc"); } setTimeout("receiveMsg()", 500); }); } //发送消息 function sendMsg(msg) { callAjax(ajaxforSend, "action=send&name=" + chatName + "&msg=" + escape(msg), function (rs) { if (rs.success) { showChatMsgs(rs.msgs, "sd"); oMsg.value = null; //alert("发送成功!"); } }); } //显示消息 function showChatMsgs(msgs, cssClass) { var loadonline = false; for (var i = 0; i < msgs.length; i++) { var msg = msgs[i]; oChatmsgbox.innerHTML += "<div class='" + cssClass + "'><p>[" + msg.name + "] - " + msg.sendtime + " 说:<br/>" + msg.content + "</p></div>"; if (msg.type == "on" || msg.type == "off") { loadonline = true; } } if (loadonline) { loadOnlineChatNames(); } } //调用AJAX function callAjax(ajax, param, callback) { ajax.open("post", "ChatHandler.ashx", true); ajax.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); ajax.onreadystatechange = function () { if (ajax.readyState == 4 && ajax.status == 200) { var json = eval("(" + ajax.responseText + ")"); callback(json); } }; ajax.send(param); } //获取AJAX对象(XMLHttpRequest) function getAjaxObject() { var xmlhttp; if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari xmlhttp = new XMLHttpRequest(); } else {// code for IE6, IE5 xmlhttp = new ActiveXObject("Microsoft.XMLHTTP"); } return xmlhttp; } </script> </body> </html>
代码很简单,并都有注释,在此就不作说明了,如果有疑问欢迎在下方评论。
服务端(ChatHandler.ashx)
<%@ WebHandler Language="C#" Class="ChatHandler" %> using System; using System.Web; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Web.Script.Serialization; using System.Threading; using System.Collections.Concurrent; public class ChatHandler : IHttpHandler { private class Msg { public string name { get; set; } public string sendtime { get; set; } public string content { get; set; } public string readednams { get; set; } public int readedCount { get; set; } public string type { get; set; } } private static List<Msg> msgs = new List<Msg>(); private static ReaderWriterLockSlim rwLock = new ReaderWriterLockSlim(); private static object syncObject = new object(),syncObject1 = new object(); private static List<string> onLineNames = new List<string>(); public void ProcessRequest(HttpContext context) { string chatName = context.Request.Form["name"]; string msg = context.Request.Form["msg"]; string actionName = context.Request.Form["action"]; JavaScriptSerializer jsSerializer = new JavaScriptSerializer(); object responseObject = null; switch (actionName) { case "receive": { responseObject = GetNewMessages(chatName); break; } case "send": { responseObject = SendMessage(chatName, msg, "normal"); break; } case "on": case "off": { responseObject = SetChatStatus(chatName, actionName); break; } case "onlines": { responseObject = onLineNames; break; } } context.Response.ContentType = "text/json"; context.Response.Write(jsSerializer.Serialize(responseObject)); } private object SetChatStatus(string chatName, string status) { if (status == "on") { if (onLineNames.Exists(s => s == chatName)) { return new { success = false, info = "该聊天妮称已经存在,请更换一个名称吧!" }; } lock (syncObject1) { onLineNames.Add(chatName); } SendMessage(chatName, "大家好,我进入聊天室了!", status); return new { success = true, info = string.Empty }; } else { lock (syncObject1) { onLineNames.Remove(chatName); } SendMessage(chatName, "再见,我离开聊天室了!", status); return new { success = true, info = string.Empty }; } } /// <summary> /// 获取未读的新消息 /// </summary> /// <param name="chatName"></param> /// <returns></returns> private object GetNewMessages(string chatName) { //第一种:循环处理 while (true) { var newMsgs = msgs.Where(m => m.name != chatName && !(m.readednams ?? "").Contains(chatName)).OrderBy(m => m.sendtime).ToList(); if (newMsgs != null && newMsgs.Count() > 0) { lock (syncObject) { newMsgs.ForEach((m) => { m.readednams += chatName + ","; m.readedCount++; }); int chatNameCount = onLineNames.Count(); msgs.RemoveAll(m => m.readedCount >= chatNameCount); } return new { success = true, msgs = newMsgs }; } Thread.Sleep(1000); } //第二种方法,采用自旋锁 //List<Msg> newMsgs = null; //SpinWait.SpinUntil(() => //{ // newMsgs = msgs.Where(m => m.name != chatName && !(m.readednams ?? "").Contains(chatName)).OrderBy(m => m.sendtime).ToList(); // return newMsgs.Count() > 0; //}, -1); //rwLock.EnterWriteLock(); //newMsgs.ForEach(m => //{ // m.readednams += chatName + ","; // m.readedCount++; //}); //rwLock.ExitWriteLock(); //return new { success = true, msgs = newMsgs }; } /// <summary> /// /// </summary> /// <param name="chatName"></param> /// <param name="msg"></param> /// <returns></returns> private object SendMessage(string chatName, string msg, string type) { var newMsg = new Msg() { name = chatName, sendtime = DateTime.Now.ToString("yyyy/MM/dd HH:mm"), content =HttpContext.Current.Server.HtmlEncode(msg), readednams = null, type = type }; //rwLock.EnterWriteLock(); lock (syncObject) { msgs.Add(newMsg); } //rwLock.ExitWriteLock(); return new { success = true, msgs = new[] { newMsg } }; } public bool IsReusable { get { return false; } } }
代码也相对简单,实现原理主要是:
1。聊天消息:循环获取未读的消息,在取出读的消息同时,将其标识为已读,全部已读的消息则删除;--我这里采用了两种方法,第二种方法被注释掉了,大家可以取消注释试试,也是不错的,比第一种更直观,建议使用;
2。发送消息:实例化一个消息实例并加入到聊天消息集合中;
3。状态切换:上线则加入到在线人员集合中,并生成一条上线消息放入到聊天消息集合中,离线则从在线人员集合中移除该人员信息,并生成一条离线消息放入聊天消息集合中;
注意事项,由于采用了全局静态集合,所以线程同步比较重要。
最终的实现效果展示如下:
张三:
李四:
小美:
如果觉得不错的话,给个推荐吧,你的支持是推动我不断前进的动力及写作的源泉,我一直坚持:知识在于分享,分享的同时自己也在成长,希望与大家共同成长,谢谢!
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