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, );

             socketwatch.Bind(point);

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

             //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！\r\n" + "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[ * ];
                 try
                 {
                     int length = socketServer.Receive(arrServerRecMsg);

                     string strSRecMsg = Encoding.UTF8.GetString(arrServerRecMsg, , 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 > )
                 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 > )
            {

                //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\r\n");
                    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[ * ];

                     //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, , 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。