基于socket实现的简单的聊天程序

　 记得八年前第一次使用socket做的一个五子棋程序，需要序列化棋子对象，传递到对方的电脑上。　一个偶然的机会，第二次使用socket做点事情。先看聊天服务器端的实现：

     服务器端要实现以下功能：

     1、启动服务，开启监听

     2、持续不断地接收消息

     3、发送消息

    启动服务，创建监听socket，绑定Ip和端口：

        /// <summary>
        /// 启动服务
        /// </summary>
        private void Start()
        {
            socketwatch = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            IPAddress address = IPAddress.Parse("10.0.0.31");

            IPEndPoint point = new IPEndPoint(address, 8025);

            socketwatch.Bind(point);

            //将套接字的监听队列长度限制为20  
            socketwatch.Listen(20);

            //创建一个监听线程  
            threadwatch = new Thread(watchconnecting);

            threadwatch.IsBackground = true;

            threadwatch.Start();
        }

创建接收数据的Socket：

 //监听客户端发来的请求  
        private void watchconnecting()
        {
            Socket connection = null;
            while (true)  //持续不断监听客户端发来的请求     
            {
                try
                {
                    connection = socketwatch.Accept();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message); //提示套接字监听异常     
                    break;
                }
                //获取客户端的IP和端口号  
                IPAddress clientIP = (connection.RemoteEndPoint as IPEndPoint).Address;
                int clientPort = (connection.RemoteEndPoint as IPEndPoint).Port;

                //让客户显示"连接成功的"的信息  
                string sendmsg = "连接服务端成功！
" + "本地IP:" + clientIP + "，本地端口" + clientPort.ToString();
                byte[] arrSendMsg = Encoding.UTF8.GetBytes(sendmsg);
                connection.Send(arrSendMsg);

                RemoteEndPoint = connection.RemoteEndPoint.ToString(); //客户端网络结点号  
                dic.Add(RemoteEndPoint, connection);    //添加客户端信息  

                IPEndPoint netpoint = connection.RemoteEndPoint as IPEndPoint;

                //创建一个通信线程      
                ParameterizedThreadStart pts = new ParameterizedThreadStart(recv);
                Thread thread = new Thread(pts);
                thread.IsBackground = true;//设置为后台线程，随着主线程退出而退出     
                //启动线程     
                thread.Start(connection);
            }
        }

socketwatch.Accept() 会创建一个新的socket，它用来负责和某个客户端的通讯。

接收数据：

        private void recv(object socketclientpara)
        {

            Socket socketServer = socketclientpara as Socket;
            while (true)
            {
                byte[] arrServerRecMsg = new byte[1024 * 1024];
                try
                {
                    int length = socketServer.Receive(arrServerRecMsg);

                    string strSRecMsg = Encoding.UTF8.GetString(arrServerRecMsg, 0, length);

                    this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
                              (ThreadStart)delegate()
                              {
                                  MessagePool.Insert(MessagePool.Count, new Message() { MessageInfo = strSRecMsg, IdentityName = socketServer.RemoteEndPoint.ToString() });
                              });
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message);
                    socketServer.Close();
                    break;
                }
            }
        }

把从客户端接收过来的字节流变为字符串，然后添加到页面上。

发送消息：

        private static object lockPool = new object();
        public static ObservableCollection<Message> MessagePool = new ObservableCollection<Message>();
        private void send_Click(object sender, RoutedEventArgs e)
        {
            string msg = this.message.Text;

            this.message.Clear();

            lock (lockPool)
            {
                MessagePool.Insert(MessagePool.Count, new Message() { MessageInfo = msg, IdentityName = "wbq" });
            }

            string sendMsg = msg; 
            byte[] bytes = System.Text.Encoding.UTF8.GetBytes(sendMsg);

            if (dic.Count > 0)
                dic.First().Value.Send(bytes);
        }

dic.First().Value.Send，从字典中获取到之前创建好的通讯socket，然后调用send方法。

客户端需要实现以下功能：
1、和服务器建立连接
2、接收数据
3、发送数据

建立连接：

   private void Start()
        {

            //定义一个套接字监听  
            socketclient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);


           var servers= GetServers();


           if (servers.Count > 0)
           {

               //获取文本框中的IP地址  
               IPAddress address = IPAddress.Parse(servers.First().IPToPing);

               //将获取的IP地址和端口号绑定在网络节点上  
               IPEndPoint point = new IPEndPoint(address, int.Parse(servers.First().Port));

               try
               {
                   //客户端套接字连接到网络节点上，用的是Connect  
                   socketclient.Connect(point);
               }
               catch (Exception)
               {
                   //MessageBox.  
                   MessageBox.Show("连接失败
");
                   return;
               }

               threadclient = new Thread(recv);

               threadclient.IsBackground = true;

               threadclient.Start();
           }
        }

接收消息：

       // 接收服务端发来信息的方法    
        private void recv()//  
        {
            while (true)//持续监听服务端发来的消息  
            {
                try
                {
                    //定义一个1M的内存缓冲区，用于临时性存储接收到的消息  
                    byte[] arrRecvmsg = new byte[1024 * 1024];

                    //将客户端套接字接收到的数据存入内存缓冲区，并获取长度  
                    int length = socketclient.Receive(arrRecvmsg);

                    //将套接字获取到的字符数组转换为人可以看懂的字符串  
                    string strRevMsg = Encoding.UTF8.GetString(arrRecvmsg, 0, length);

                    this.Dispatcher.BeginInvoke(DispatcherPriority.Normal,
                               (ThreadStart)delegate()
                               {
                                   MessagePool.Insert(MessagePool.Count, new Message() { MessageInfo = strRevMsg, IdentityName = socketclient.RemoteEndPoint.ToString() });
                               });
                }
                catch (Exception ex)
                {
                    MessageBox.Show("远程服务器已经中断连接" + ex.Message);
                    break;
                }
            }
        }

发送消息：

        private void send_Click(object sender, RoutedEventArgs e)
        {
            string strRevMsg = this.message.Text;
            this.message.Clear();

            lock (lockPool)
            {
                MessagePool.Insert(MessagePool.Count, new Message() { MessageInfo = strRevMsg, IdentityName = "我(" + socketclient.LocalEndPoint.ToString() + ")" });
            }

            //将输入的内容字符串转换为机器可以识别的字节数组     
            byte[] arrClientSendMsg = Encoding.UTF8.GetBytes(strRevMsg);
            //调用客户端套接字发送字节数组     
            socketclient.Send(arrClientSendMsg);
        }

经过和同事的测试，可以实现简单的文字聊天，此代码仅为测试代码，若要用于实际的项目中，需要很大改进，比如socket异步建立，消息接收和发送等等。