套接字类型：

TCP/IP的socket

Sock_stream可靠的面对连接数据传输，无差错、无重复发送，安照顺序发送接收，内设流量控制，避免数据流超限，数据为字节流，无长度限制，ftp流套接字。

Sock_DGRAM 无连接的服务，数据包以独立包的形式发送，不提供无措保证，数据可能丢失重复，发送接收的顺序混乱，网络文件系统nfs使用数据报式套接字。

Sock_Ram 接口允许较底层协议，IP，ICMP直接访问，检查新的协议实现或访问现有服务中配置的新设备。

服务端：

using System.Net;

using System.Net.Sockets;

using System.Text;

using System.Threading;

Thread mythread ;

Socket socket;

// 清理所有正在使用的资源。

         protected override void Dispose( bool disposing )

          {

               try

　             {

　　           socket.Close();//释放资源

　　           mythread.Abort ( ) ;//中止线程

　             }

　             catch{ }

              if( disposing )

               {

                    if (components != null)

                    {

                        components.Dispose();

                    }

               }

               base.Dispose( disposing );

          }        

          public static IPAddress GetServerIP()

          {

               IPHostEntry ieh=Dns.GetHostByName(Dns.GetHostName());

               return ieh.AddressList[0];

          }

          private void BeginListen()

          {

               IPAddress ServerIp=GetServerIP();

               IPEndPoint iep=new IPEndPoint(ServerIp,8000);

               socket=new

                        Socket(AddressFamily.Inte.Network,SocketType.Stream,ProtocolType.Tcp);

               byte[] byteMessage=new byte[100];  

               this.label1.Text=iep.ToString();

               socket.Bind(iep);  

//             do

               while(true)

               {

                    try

                    {

                        socket.Listen(5);

                        Socket newSocket=socket.Accept();

                        newSocket.Receive(byteMessage);

                        string sTime = DateTime.Now.ToShortTimeString ( ) ;

string msg=sTime+":"+"Message from:";

msg+=newSocket.RemoteEndPoint.ToString()+Encoding.Default.GetString(byteMessage);

                        this.listBox1.Items.Add(msg);

                    }

                    catch(SocketException ex)

                    {

                        this.label1.Text+=ex.ToString();

                    }

               }

//             while(byteMessage!=null);

          }

          //开始监听

          private void button1_Click(object sender, System.EventArgs e)

          {

               try

               {

                    mythread = new Thread(new ThreadStart(BeginListen));

                    mythread.Start();

               }

               catch(System.Exception er)

               {

                    MessageBox.Show(er.Message,"完成",MessageBoxButtons.OK,MessageBoxIcon.Stop);

               }

          }

客户端：

using System.Net;

using System.Net.Sockets;

using System.Text;

          private void button1_Click(object sender, System.EventArgs e)

          {

               BeginSend();       

          }

          private void BeginSend()

          {             

               string ip=this.txtip.Text;

               string port=this.txtport.Text;

               IPAddress serverIp=IPAddress.Parse(ip);            

               int serverPort=Convert.ToInt32(port);

               IPEndPoint iep=new IPEndPoint(serverIp,serverPort);  

               byte[] byteMessage;  

//             do

//             {

                    Socket socket=new Socket(AddressFamily.Inte.Network,SocketType.Stream,ProtocolType.Tcp);

                    socket.Connect(iep);

                    byteMessage=Encoding.ASCII.GetBytes(textBox1.Text);

                    socket.Send(byteMessage);

                    socket.Shutdown(SocketShutdown.Both);

                    socket.Close();

//             }

//             while(byteMessage!=null);

          }