如何使用Socket.IO编写聊天应用程序

我们将首先通过查看客户端代码。所有聊天互动都有HomeView处理，首先需要在 /public/js/models/main.js中定义HomeModel。

var HomeModel = Backbone.Model.extend({

 defaults: {

   // Backbone collection for users

   onlineUsers: new UserCollection(),

   // Backbone collection for user chats, 初始化一个预定义聊天模型

   userChats: new ChatCollection([

     new ChatModel({sender: '', message: 'Chat Server v.1'})

   ])

 },

 // 添加一个新用户到 onlineUsers collection

 addUser: function(username) {

   this.get('onlineUsers').add(new UserModel({name: username}))

 },

 // 从onlineUsers collection中移除一个用户

 removeUser: function(username) {

   var onlineUsers = this.get('onlineUsers')

   var u = onlineUsers.find(function(item) {

         return item.get('name') == username

       })

   if (u) {

     onlineUsers.remove(u)

   }

 },

 // 添加一个新的聊天到 userChats collection

 addChat: function(chat) {

   this.get('userChats').add(new ChatModel({sender: chat.sender, message: chat.message}))

 },

})

我们利用Backbone集合来侦听集合变化。这些集合的更新会直接由视图自动反映出来。接下来，需要在/public/index.html中定义home模板。

<script type="text/template" id="home-template">

 <div class="row">

   <div class="col-md-10">做数

     <div class="panel panel-default">

       <div class="panel-heading">Lobby</div>

       <div class="panel-body">

         <div class="nano">

           <div class="content">

             <div class="list-group" id="chatList"></div>

           </div>

         </div>

         <form>

           <input class="form-control" type="text" id="chatInput"><纯丛首/input>

         </form>

       </div>

     </div>

   </div>

   <div class="col-md-2">

     <div class="panel panel-default">

       <div class="panel-heading">

         <h3 class="panel-title">Online Users <span class="badge pull-right" id="userCount"></span></h3>

       </div>

       <div class="panel-body">

         <div class="nano">

           <div class="content">

             <div class="list-group" id="userList"></div>

           <郑凳/div>

         </div>

       </div>

     </div>

   </div>

 </div>

</script>

聊天客户端

接下来， 让我们来定义 我们的 Socket.IO 聊天客户端 。 客户端 与服务器端的通信，主要通过发送消息和监听通知 来完成。 这些通知 触发事件 与所述控制器 进行通信。请参阅 下面 /public/ JS / socketclient.js的代码 。

var ChatClient = function(options) {

 // 避免冲突

 var self = this

 // app event bus

 self.vent = options.vent

 // server hostname replace with your server's hostname eg: http://localhost

 self.hostname = 'http://chatfree.herokuapp.com'

 // connects to the server

 self.connect = function() {

   // connect to the host

   self.socket = io.connect(self.hostname)

   // set responseListeners on the socket

   self.setResponseListeners(self.socket)

 }

 // send login message

 self.login = function(name) {

   self.socket.emit('login', name)

 }

 // send chat message

 self.chat = function(chat) {

   self.socket.emit('chat', chat)

 }

 self.setResponseListeners = function(socket) {

   // handle messages from the server

   socket.on('welcome', function(data) {

     // request server info

     socket.emit('onlineUsers')

     self.vent.trigger('loginDone', data)

   })

   socket.on('loginNameExists', function(data) {

     self.vent.trigger('loginNameExists', data)

   })

   socket.on('loginNameBad', function(data) {

     self.vent.trigger('loginNameBad', data)

   })

   socket.on('onlineUsers', function(data) {

     console.log(data)

     self.vent.trigger('usersInfo', data)

   })

   socket.on('userJoined', function(data) {

     self.vent.trigger('userJoined', data)

   })

   socket.on('userLeft', function(data) {

     self.vent.trigger('userLeft', data)

   })

   socket.on('chat', function(data) {

     self.vent.trigger('chatReceived', data)

   })

 }

}

使用Socket.IO可以非常简单的发送和接受通信数据，上面的代码中，使用了下面的两个方法

socket.emit(message, [callback])  向服务器端发送消息

socket.on(message, callback)      用于接收来自服务器的消息

让我们来看一下他们的通信协议

主控制器

客户端最后一步，主控制器，它控制了VIEW，MODEL和socket客户端，代码在/public/js/main.js中

var MainController = function() {

 var self = this

 // Event Bus for socket client

 self.appEventBus = _.extend({}, Backbone.Events)

 // Event Bus for Backbone Views

 self.viewEventBus = _.extend({}, Backbone.Events)

 // initialize function

 self.init = function() {

   // create a chat client and connect

   self.chatClient = new ChatClient({vent: self.appEventBus})

   self.chatClient.connect()

   // create our views, place login view inside container first.

   self.loginModel = new LoginModel()

   self.containerModel = new ContainerModel({

     viewState: new LoginView({

       vent: self.viewEventBus,

       model: self.loginModel

     })

   })

   self.containerView = new ContainerView({model: self.containerModel})

   self.containerView.render()

 }

 // View Event Bus Message Handlers

 self.viewEventBus.on('login', function(name) {

   // socketio login

   self.chatClient.login(name)

 })

 self.viewEventBus.on('chat', function(chat) {

   // socketio chat

   self.chatClient.chat(chat)

 })

 // Socket Client Event Bus Message Handlers

 // triggered when login success

 self.appEventBus.on('loginDone', function() {

   self.homeModel = new HomeModel()

   self.homeView  = new HomeView({vent: self.viewEventBus, model: self.homeModel})

   // set viewstate to homeview

   self.containerModel.set('viewState', self.homeView)

 })

 // triggered when login error due to bad name

 self.appEventBus.on('loginNameBad', function(name) {

   self.loginModel.set('error', 'Invalid Name')

 })

 // triggered when login error due to already existing name

 self.appEventBus.on('loginNameExists', function(name) {

   self.loginModel.set('error', 'Name already exists')

 })

 // triggered when client requests users info

 // responds with an array of online users.

 self.appEventBus.on('usersInfo', function(data) {

   var onlineUsers = self.homeModel.get('onlineUsers')

   var users = _.map(data, function(item) {

     return new UserModel({name: item})

   })

   onlineUsers.reset(users)

 })

 // triggered when a client joins the server

 self.appEventBus.on('userJoined', function(username) {

   self.homeModel.addUser(username)

   self.homeModel.addChat({sender: '', message: username + ' joined room.'})

 })

 // triggered when a client leaves the server

 self.appEventBus.on('userLeft', function(username) {

   self.homeModel.removeUser(username)

   self.homeModel.addChat({sender: '', message: username + ' left room.'})

 })

 // triggered when chat receieved

 self.appEventBus.on('chatReceived', function(chat) {

   self.homeModel.addChat(chat)

 })

}

最后，我们需要定义一个MainController入口，调用init方法，代码位于/public/js/main.js中

聊天服务器端

应用程序的最后一部分是聊天服务器。它主要负责维护在线用户列表，广播聊天消息。比如，首先，服务器会给一个新的客户的连接请求命名，然后通过刚刚建立的socket，连接事件handlers。socket handler处理如下事件：    socket.on(message, callback)  - 在收到新邮件时回调函数被调用。消息可以是任何类型的数据，这取决于发送的消息。    socket.on('disconnect', callback) - 当socket断开连接时候，回调函数被调用。    socket.emit(message, args) - 通过socket发送消息。     socket.broadcast.send(message, args)  - 广播信息到除发送者之外的所有socket。现在，我们已经看到了handler socket是如何工作的。首先，需要在/scripts/chatserver.js中定义一个用户模型 ：

总结

我们已经看到了如何使用Backbone和Socket.IO构建一个简单的聊天应用程序。还有很多没有在本文中涉及的Socket.IO性能，例如rooms和namespaces。通过这篇文章，我们可以看出使用Socket.IO很容易的在客户端和服务器端交换消息。

面向无连接的端对端通信灶姿喊

//#include <winsock2.h>

//#pragma comment(lib,"WS2_32.lib")

WSADATA wsd

SOCKET s

char buf[1024]

if(WSAStartup(MAKEWORD(2,2),&wsd)!=0)

{

return -1//失败册郑

}

s=socket(AF_INET,SOCK_DGRAM,0)

if(s==INVALID_SOCKET)

{

WSACleanup()

return -1//创建套接字失败隐野

}

SOCKADDR_IN servAddr

servAddr.sin_family=AF_INET

servAddr.sin_addr.s_addr=inet_addr(%%1)

servAddr.sin_port=htons(INADDR_ANY)

if(bind(s,(SOCKADDR*)&servAddr,sizeof(SOCKADDR_IN))==SOCKET_ERROR)

{

closesocket(s)

WSACleanup()

return -1//绑定套接字失败

}

int nServAddrlen=sizeof(servAddr)

ZeroMemory(buf,sizeof(buf))

if(recvfrom(s,buf,size(buf),0,(SOCKADDR*)&servAddr,nServAddrlen)==SOCKET_ERROR)

{

closesocket(s)

WSACleanup()

return -1//接收数据失败

}

CString %%2(buf)

ZeroMemory(buf,sizeof(buf))

strcpy(buf,%%3)

SOCKADDR_IN clientAddr

clientAddr.sin_family=AF_INET

clientAddr.sin_addr.s_addr=inet_addr(%%4)

clientAddr.sin_port=htons((short)%%5)

int nClientlen=size(clientAddr)

if(sendto(s,buf,sizeof(buf),0,(SOCKADDR*)&clientAddr,nClientlen)==SOCKET_ERROR)

{

closesocket(s)

WSACleanup()

return -1//向服务器发送数据失败

}

closesocket(s)

WSACleanup()

#include <stdio.h>

#include <winsock2.h>

#define MAX_SIZE 200

void main(void) {

WORD wVersionRequested

WSADATA wsaData

int err

wVersionRequested = MAKEWORD( 1, 1 )

err = WSAStartup( wVersionRequested, &wsaData )

if ( err != 0 ) {

/* Tell the user that we could not find a usable */

/* WinSock DLL. */

return

}

/* Confirm that the WinSock DLL supports 2.2.*/

/* Note that if the DLL supports versions greater*/

/* than 2.2 in addition to 2.2, it will still return */

/* 2.2 in wVersion since that is the version we */

/* requested.*/

if ( LOBYTE( wsaData.wVersion ) != 1 ||

HIBYTE( wsaData.wVersion ) != 1 ) {

/* Tell the user that we could not find a usable */

/* WinSock DLL. */

WSACleanup( )

return

}

SOCKET sockSrv = socket(AF_INET, SOCK_DGRAM, 0)

SOCKADDR_IN addrSrv

addrSrv.sin_addr.S_un.S_addr = htonl(INADDR_ANY)

addrSrv.sin_family = AF_INET

addrSrv.sin_port = htons(6000)

bind(sockSrv, (SOCKADDR *)&addrSrv, sizeof(SOCKADDR))

SOCKADDR addrClient

char recvBuffer[MAX_SIZE]

memset(recvBuffer, 0, sizeof(recvBuffer))

int len = sizeof(SOCKADDR)

recvfrom(sockSrv, recvBuffer, sizeof(recvBuffer), 0, (SOCKADDR *)&addrClient, &len)

printf("%s\n", recvBuffer)

closesocket(sockSrv)

}

#include <stdio.h>

#include <winsock2.h>肆禅

void main(void) {

WORD wVersionRequested

WSADATA wsaData

int err

wVersionRequested = MAKEWORD( 1, 1 )

err = WSAStartup( wVersionRequested, &wsaData )

if ( err != 0 ) {

/指雹斗* Tell the user that we could not find a usable */

/* WinSock DLL. */

return

}

/唯磨* Confirm that the WinSock DLL supports 2.2.*/

/* Note that if the DLL supports versions greater*/

/* than 2.2 in addition to 2.2, it will still return */

/* 2.2 in wVersion since that is the version we */

/* requested.*/

if ( LOBYTE( wsaData.wVersion ) != 1 ||

HIBYTE( wsaData.wVersion ) != 1 ) {

/* Tell the user that we could not find a usable */

/* WinSock DLL. */

WSACleanup( )

return

}

/* The WinSock DLL is acceptable. Proceed. */

SOCKET sockClient = socket(AF_INET, SOCK_DGRAM, 0)

SOCKADDR_IN addrClient

addrClient.sin_addr.S_un.S_addr = inet_addr("127.0.0.1")

addrClient.sin_family = AF_INET

addrClient.sin_port = htons(6000)

sendto(sockClient, "你若此生若只如一瞬", strlen("你若此生若只如一瞬"), 0, (SOCKADDR *)&addrClient, sizeof(SOCKADDR))

closesocket(sockClient)

WSACleanup()

}

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