1、运行效果

图1 启动服务端

图2 启动客户端

图3 客户发消息

图4 服务端发消息

图5 客户主动关闭，服务段打印异常详情

2、服务器端源码

服务端和客户端都要添加一下namespace：

using System.Net;

using System.Net.Sockets;

using System.Threading;

源码：

 class Program      {          private static string serverIP = "192.168.3.42";//本机ip地址          private static int serverPort = 8888;          private static int bufferSize = 1024;          private static int count = 0;//表示对话序号            static void Main(string[] args)          {              IPAddress ip = IPAddress.Parse(serverIP);              IPEndPoint ipe = new IPEndPoint(ip, serverPort);              Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);              try              {                  s.Bind(ipe);                  s.Listen(10);                  Console.WriteLine("等待连接……");              }              catch (Exception ex)              {                  Console.WriteLine(ex);              }              Thread mainTrd = new Thread(Run);              mainTrd.Start(s);          }          /// <summary>          /// 启动服务器的socket。          /// 此处要想修改为多用户连接，对每个新用户都new一个RecMsg线程，并且Dictionary<T1,T2>存储每一对ipe和socket即可          /// </summary>          /// <param name="o">传入的socket对象</param>          private static void Run(object o)          {              Socket socket = o as Socket;              try              {                                 Socket connSocket = socket.Accept();                  //客户和服务器连接成功。                  Console.WriteLine("{0}成功连接到本机。", connSocket.RemoteEndPoint);                  //接下来的事情交给会话线程                  Thread recTh = new Thread(RecMsg);                  recTh.Start(connSocket);                  Thread sendTh = new Thread(SendMsg);                  sendTh.Start(connSocket);              }              catch (Exception ex)              {                  Console.WriteLine(ex);                  throw;              }          }          private static void RecMsg(object o)          {              Socket connSocket = o as Socket;              while (true)              {                  byte[] buffer = new Byte[bufferSize];                  try                  {                      int length = connSocket.Receive(buffer);                      byte[] realBuffer = new Byte[length];                      Array.Copy(buffer, 0, realBuffer, 0, length);                      string str = System.Text.Encoding.Default.GetString(realBuffer);                      Console.Write("[{0}] ", count++);                      Console.WriteLine("{0}说：{1}.", connSocket.RemoteEndPoint, str);                  }                  catch (Exception ex)                  {                      Console.WriteLine(ex);                      Console.ReadKey();                      break;                  }                                          }          }          private static void SendMsg(object o)           {              Socket connSocket = o as Socket;              while (true)              {                  string str = Console.ReadLine();                  if (str != string.Empty)                  {                      byte[] buffer = Encoding.Default.GetBytes(str);                      connSocket.Send(buffer, buffer.Length, SocketFlags.None);                  }                             }          }      }

3、客户端源码

class Program      {          private static string host = "192.168.3.42";          private static int port = 8888;          private static int bufferSize = 1024;          static IPAddress ip = IPAddress.Parse(host);          static IPEndPoint ipe = new IPEndPoint(ip, port);          private static int count = 0;//表示对话序号          static void Main(string[] args)          {                          Socket s = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);              try              {                  s.Connect(ipe);                  Console.WriteLine("成功连接到{0}。", s.RemoteEndPoint);                  Console.WriteLine("请输入要发送给服务器的话，按Enter发送。");              }              catch (Exception ex)              {                  Debug.WriteLine(ex);                  throw;              }              Thread clientTh = new Thread(SendToServer);              clientTh.Start(s);              Thread recTh = new Thread(RecMsg);              recTh.Start(s);                      }          private static void RecMsg(object o)          {              Socket connSocket = o as Socket;              while (true)              {                  byte[] buffer = new Byte[bufferSize];                  try                  {                      int length = connSocket.Receive(buffer);                      byte[] realBuffer = new Byte[length];                      Array.Copy(buffer, 0, realBuffer, 0, length);                      string str = System.Text.Encoding.Default.GetString(realBuffer);                      Console.Write("[{0}] ", count++);                      Console.WriteLine("{0}说：{1}.", connSocket.RemoteEndPoint, str);                  }                  catch (Exception ex)                  {                      Console.WriteLine(ex);                      Console.ReadKey();                      break;                  }              }          }          private static void SendToServer(object o)          {                          Socket socket = o as Socket;                          while (true)              {                  try                  {                      string str = Console.ReadLine();                                          if (str != string.Empty)                      {                          byte[] bt = Encoding.Default.GetBytes(str);                          socket.Send(bt, bt.Length, 0);                      }                  }                  catch (Exception ex)                  {                      Console.WriteLine("发送失败。");                      Debug.WriteLine(ex);                      throw;                  }              }                               }      }

来自：http://my.oschina.net/SnifferApache/blog/406563