求助该如何写一个用localhost的代理服务器！！！
下面是我大致写的代码，我是初学者，想写一个本地的代理服务器（用localhost做代理）。这段代码还没完成，只是停留在读取分析了localhost接收到request的阶段，现在想把request发到服务器上然后接收数据，但是我运行之后基本没反应。后来我试了一下，RequestHandler的DoRequest里面s.Send之后根本Receive不到数据（int bytesRec = s.Receive(bytes）是0);，是我之前s.Connect的时候失败了吗？ 如果可以的话，麻烦哪个高人可以发一个可以用的代理代码给我学习一下吗，谢谢了！

C# code

using System;using System.Net;using System.Net.Sockets;using System.Threading;namespace LocalProxy{    class Program    {        static void Main(string[] args)        {            const int DEFPORTNUM = 8080;            int port2use = DEFPORTNUM;            const int BACKLOG = 10; // maximum length of pending connections queue                        Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);            // Establish the local endpoint for the socket            IPAddress ipAddress = IPAddress.Loopback;                        IPEndPoint localEndPoint = new IPEndPoint(ipAddress, port2use);            listener.Bind(localEndPoint);            listener.Listen(BACKLOG);            System.Console.WriteLine("Listening ... " + localEndPoint.ToString());                        while (true)            {                Socket sock = listener.Accept();                if(sock.Connected)                    System.Console.WriteLine("Connection established");                RequestHandler rh = new RequestHandler(sock,port2use);                Thread rhThread = new Thread(new ThreadStart(rh.DoRequest));                rhThread.Start();                Console.WriteLine(rh.Response);            }        }    }}

C# code

using System;using System.Net;using System.Net.Sockets;namespace LocalProxy{   public class RequestHandler   {      public RequestHandler(string host, int port,          string httpVersion, string resource,         string requestMethod, string requestHeaders)      {         Host = host;         Port = port;         HttpVersion = httpVersion;         Resource = resource;         RequestMethod = requestMethod;         RequestHeaders = requestHeaders;      } // RequestHandler      public RequestHandler(Socket sock,int port)      {          System.Text.Encoding utf8 = System.Text.Encoding.UTF8;          // Get the HTTP headers first          string header = "";          while (true)          {              byte[] bytes = new byte[1];              int bytesRec = sock.Receive(bytes);              header += System.Text.Encoding.ASCII.GetString(bytes, 0, bytesRec);              if (header.IndexOf("\r\n\r\n") > -1 || header.IndexOf("\n\n") > -1)              {                  break;              }          }          //System.Console.WriteLine("*** Headers ***\n " + header);          // Break up the headers          string[] headers = header.Split(new char[] { '\n' });          string requestLine = headers[0];          string[] requestLineElements = requestLine.Split(new char[] { ' ' });          Port = port;          RequestMethod = requestLineElements[0];          Resource = requestLineElements[1];          HttpVersion = requestLineElements[2];          Host = getHost(Resource);          for (int i = 1; i < headers.Length; i++)          {              RequestHeaders += headers[i] + "\r\n";          }          /*          Console.WriteLine("Request method:" + RequestMethod);          Console.WriteLine("Resource: " + Resource);          Console.WriteLine("HttpVersion:" + HttpVersion);          Console.WriteLine("Host: " + Host);          Console.WriteLine("Request Headers: \n" + RequestHeaders);*/      }      public void DoRequest()      {         System.Text.Encoding utf8 = System.Text.Encoding.UTF8;         const int BUFSZ = 1024;                  try         {            // IPAddress and IPEndPoint represent the endpoint that will            //   receive the request.            // Get the first IPAddress in the list using DNS.            IPAddress hostadd = Dns.GetHostEntry(Host).AddressList[0];            if ( Host == "localhost" )            {               hostadd = IPAddress.Loopback;            }            IPEndPoint remoteEndPoint = new IPEndPoint(hostadd, Port);            //Creates the Socket for sending data over TCP.            Socket s = new Socket(AddressFamily.InterNetwork,                SocketType.Stream, ProtocolType.Tcp);            s.ReceiveTimeout = 6*1000; // Set time out (milliseconds)             // Connects to the host using IPEndPoint.            s.Connect(remoteEndPoint);            Console.WriteLine("Sock connected!");                     // Sends the resource request to the host.            string getString = RequestMethod + " "               + Resource + " "               + HttpVersion + "\r\n"               + RequestHeaders               + "\r\n\r\n";            byte[] getBytes  = utf8.GetBytes(getString);            s.Send(getBytes, getBytes.Length, SocketFlags.None);            Console.WriteLine("socket sent");             // Get the HTTP headers first            string header = "";                                    while (true)             {                              byte[] bytes = new byte[1];               int bytesRec = s.Receive(bytes);               header += System.Text.Encoding.UTF8.GetString(bytes,0, bytesRec);               if ( header.IndexOf("\r\n\r\n") > -1 || header.IndexOf("\n\n") > -1 )                {                  break;               }            }                              // Break up the headers            string[] headers = header.Split(new char[] {'\n'});            // Get the HTTP payload next            string data = header;                  int contentLength = GetContentLength(headers);            if ( RequestMethod == "HEAD" )            {               contentLength = 0; // no contents for "HEAD"            }            try            {               if ( contentLength > 0 )               {                  int bytesRecd = 0;                  while ( bytesRecd < contentLength )                  {                     byte[] bytes = new byte[BUFSZ];                     int bytesNowGot = s.Receive(bytes);                     bytesRecd += bytesNowGot;                     data += System.Text.Encoding.UTF8.GetString(bytes,                        0, bytesNowGot);                  }               }               else                {                   int bytesNowGot = 0;                  do                  {                     byte[] bytes = new byte[BUFSZ];                     bytesNowGot = s.Receive(bytes);                     data += System.Text.Encoding.UTF8.GetString(bytes,                        0, bytesNowGot);                  } while ( bytesNowGot > 0 );               }            }            catch (System.Exception)            {            }                           Response = data;            s.Shutdown(SocketShutdown.Both);            s.Close();         }         catch (Exception x)         {            Response = x.ToString();         }      } // DoRequest      private string getHost(string Resource)      {          string Host = "";          int index1 = Resource.IndexOf("//") + 2;          int index2 = Resource.IndexOf('/', index1);          int length = index2 - index1;          Host = Resource.Substring(index1, length);          return Host;      }      private static int GetContentLength(string[] headers)      {         int rval = 0;         for ( int i = 1; i < headers.Length; ++i ) // 0 = requestLine         {            string[] hElem = headers[i].Split(new char[] {':'});            if ( hElem.Length >= 2 )            {               if ( hElem[0].Trim().ToLowerInvariant().Equals("content-length") )               {                  rval = Int32.Parse(hElem[1].Trim());               }            }         }         return rval;      } // GetContentLength      public string Host      {          get;          private set;      } // Host      public int Port      {          get;          private set;      } // Port      public string HttpVersion      {          get;          private set;      } // HttpVersion      public string Resource      {          get;          private set;      } // Resource      public string RequestMethod      {          get;          private set;      } // RequestMethod      public string RequestHeaders      {          get;          private set;      } // RequestHeaders      public string Response      {          get;          private set;      } // Response   } // class RequestHandler} // namespace LocalProxy 
 

C# code

if (contentLength > 0)                        {                            int bytesRecd = 0;                            while (bytesRecd < contentLength)                            {                                byte[] bytes = new byte[BUFSZ];                                int bytesNowGot = s.Receive(bytes);                                for(int i = 0 ; i < bytesNowGot; i++)                                {                                    ResponseBytesList.Add(bytes[i]);                                }                                bytesRecd += bytesNowGot;                                data += System.Text.Encoding.UTF8.GetString(bytes, 0, bytesNowGot);                            }                        }                        else                        {                            int bytesNowGot = 0;                            do                            {                                byte[] bytes = new byte[BUFSZ];                                bytesNowGot = s.Receive(bytes);                                for (int i = 0; i < bytesNowGot; i++)                                {                                    ResponseBytesList.Add(bytes[i]);                                }                                data += System.Text.Encoding.UTF8.GetString(bytes, 0, bytesNowGot);                            } while (bytesNowGot > 0);                        }                        //ResponseBytes = utf8.GetBytes(data);                        ResponseBytes = ResponseBytesList.ToArray();                        clientSock.Send(ResponseBytes);