using System;using System.Collections.Generic;using System.Text;using System.Net.Sockets;using System.Net;using System.IO;namespace ConsoleApplication1{  Class Program  {    static void Main (String[] args)    {      // 1. to create a socket      Socket sListen = new Socket (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);      // 2. Fill IP      IPAddress IP = IPAddress.Parse ("127.0.0.1");      IPEndPoint IPE = new IPEndPoint (IP, 4321);      // 3. binding      sListen.Bind (IPE);      // 4. Monitor      Console.WriteLine ("Service is listening ...");      sListen.Listen (2);      // 5. loop to accept client connection requests      while (true)      {        Socket clientSocket;        try        {          clientSocket = sListen.Accept ();        }        catch        {          throw;        }        // send data to the client        //clientSocket.Send (Encoding.Unicode.GetBytes ("I am a server, you there?? !!!!"));        // send the file        byte[] buffer = ReadImageFile ("1.jpg");        clientSocket.Send (buffer, buffer.Length, SocketFlags.None);        Console.WriteLine ("Send success!");      }    }    private static byte[] ReadImageFile (String img)    {      FileInfo fileinfo = new FileInfo (img);      byte[] buf = new byte[fileInfo.Length];      FileStream fs = new FileStream (img, FileMode.Open, FileAccess.Read);      fs.Read (buf, 0, buf.Length);      fs.Close ();      //fileInfo.Delete ();      GC.ReRegisterForFinalize (fileinfo);      GC.ReRegisterForFinalize (fs);      return buf;    }  }}

using System;using System.Collections.Generic;using System.Text;using System.Net.Sockets;using System.Net;using System.IO;namespace ConsoleApplication2{  Class Program  {    static void Main (String[] args)    {      // 1. to create a socket      Socket S = new Socket (AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);      // 2. fill in the remote IP      IPAddress IP = IPAddress.Parse ("127.0.0.1");      IPEndPoint IPE = new IPEndPoint (IP, 4321);      Console.WriteLine ("started connection service ....");      // 3. connect to the server      s.Connect (IPE);      // 4. receive data      byte[] buffer = new byte[1000000];      s.Receive (buffer, buffer.Length, SocketFlags.None);      //var Msg = Encoding.Unicode.GetString (buffer);      //Console.WriteLine ("received message: (0)", msg);      Console.WriteLine ("Receive success");      FileStream fs = File.Create ("1.jpg");      fs.Write (buffer, 0, buffer.Length);      fs.Close ();      Console.ReadKey ();    }  }}