1:  using System;

   2:  using System.Net;

   3:  using System.Net.Sockets;

   4:  using System.Text;

   5:   

   6:  namespace SocketAsyncServer

   7:  {

   8:      public static class Program

   9:      {

  10:          public static void Main(String[] args)

  11:          {

  12:              IPAddress[] addressList = Dns.GetHostEntry(Environment.MachineName).AddressList;

  13:              new TcpListener().Listen(new IPEndPoint(addressList[addressList.Length - 1], 9900));

  14:   

  15:              Console.ReadKey();

  16:          }

  17:      }

  18:   

  19:      public class TcpListener

  20:      {

  21:          private SocketAsyncEventArgs Args;

  22:          private Socket ListenerSocket;

  23:          private StringBuilder buffers;

  24:          public TcpListener() { }

  25:          public void Listen(EndPoint e)

  26:          {

  27:              //buffer

  28:              buffers = new StringBuilder();

  29:              //socket

  30:              ListenerSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

  31:              ListenerSocket.Bind(e);

  32:              ListenerSocket.Listen(10);

  33:              //异步socket事件

  34:              Args = new SocketAsyncEventArgs();

  35:              Args.Completed += new EventHandler<SocketAsyncEventArgs>(ProcessAccept);

  36:              BeginAccept(Args);

  37:              Console.WriteLine("server run at {0}", e.ToString());

  38:          }

  39:   

  40:          //开始接受

  41:          void BeginAccept(SocketAsyncEventArgs e)

  42:          {

  43:              e.AcceptSocket = null;

  44:              if (!ListenerSocket.AcceptAsync(e))

  45:                  ProcessAccept(ListenerSocket, e);

  46:          }

  47:          //接受完毕 开始接收和发送

  48:          void ProcessAccept(object sender, SocketAsyncEventArgs e)

  49:          {

  50:              Socket s = e.AcceptSocket;

  51:              e.AcceptSocket = null;

  52:   

  53:              int bufferSize = 10;//1000 * 1024;

  54:              var args = new SocketAsyncEventArgs();

  55:              args.Completed += new EventHandler<SocketAsyncEventArgs>(OnIOCompleted);

  56:              args.SetBuffer(new byte[bufferSize], 0, bufferSize);

  57:              args.AcceptSocket = s;

  58:              if (!s.ReceiveAsync(args))

  59:                  this.ProcessReceive(args);

  60:   

  61:              BeginAccept(e);

  62:          }

  63:   

  64:          //IOCP回调

  65:          void OnIOCompleted(object sender, SocketAsyncEventArgs e)

  66:          {

  67:              switch (e.LastOperation)

  68:              {

  69:                  case SocketAsyncOperation.Receive:

  70:                      this.ProcessReceive(e);

  71:                      break;

  72:                  case SocketAsyncOperation.Send:

  73:                      this.ProcessSend(e);

  74:                      break;

  75:                  default:

  76:                      throw new ArgumentException("The last operation completed on the socket was not a receive or send");

  77:              }

  78:          }

  79:          

  80:          //接收完毕

  81:          void ProcessReceive(SocketAsyncEventArgs e)

  82:          {

  83:              if (e.BytesTransferred > 0)

  84:              {

  85:                  if (e.SocketError == SocketError.Success)

  86:                  {

  87:                      //读取

  88:                      var data=Encoding.ASCII.GetString(e.Buffer, e.Offset, e.BytesTransferred);

  89:                      buffers.Append(data);

  90:                      Console.WriteLine("Received:{0}", data);

  91:   

  92:                      if (e.AcceptSocket.Available == 0)

  93:                      {

  94:                          //读取完毕

  95:                          Console.WriteLine("Receive Complete.Data:{0}", buffers.ToString());

  96:                          //重置

  97:                          buffers = new StringBuilder();

  98:                          //发送反馈

  99:                          Byte[] sendBuffer = Encoding.ASCII.GetBytes("result from server");

 100:                          e.SetBuffer(sendBuffer, 0, sendBuffer.Length);

 101:                          if (!e.AcceptSocket.SendAsync(e))

 102:                          {

 103:                     

 104:                              this.ProcessSend(e);

 105:                          }

 106:                      }

 107:                      else if (!e.AcceptSocket.ReceiveAsync(e))

 108:                      {

 109:                          this.ProcessReceive(e);

 110:                      }

 111:                  }

 112:                  else

 113:                  {

 114:                      //this.ProcessError(e);

 115:                  }

 116:              }

 117:              else

 118:              {

 119:                  //this.CloseClientSocket(e);

 120:              }

 121:          }

 122:          //发送完毕

 123:          void ProcessSend(SocketAsyncEventArgs e)

 124:          {

 125:              if (e.SocketError == SocketError.Success)

 126:              {

 127:   

 128:                  if (!e.AcceptSocket.ReceiveAsync(e))

 129:                  {

 130:                      this.ProcessReceive(e);

 131:                  }

 132:              }

 133:              else

 134:              {

 135:   

 136:              }

 137:          }

 138:      }

 139:       

 140:  }