使用C#与NNTP服务器交互!

　　
using System;
using System.Text;
using System.Net;
using System.IO;
using System.Net.Sockets;
using System.Collections;
using System.Diagnostics;
namespace NntpTools {
/// <summary>
/// Class1 的摘要说明。
/// </summary>
class Debug {
  /// <summary>
  /// 应用程序的主入口点。
  /// </summary>
  [STAThread]
  static void Main(string[] args) {
   NNTPClass nc=new NNTPClass();
   nc.Connect("msnews.microsoft.com");
   ArrayList grouplist=nc.GetNewsgroups();
   for(int i=0;i<grouplist.Count;i++){
    Console.WriteLine(grouplist.ToString());
   }
   ArrayList cardlist=nc.GetNews("microsoft.public.cn.dotnet.framework");
   Console.WriteLine("=============================================================");
   StreamWriter sw=File.CreateText("c:\\news.txt");
   for(int i=0;i<cardlist.Count;i++){
    Console.WriteLine(cardlist.ToString());
    sw.WriteLine(cardlist.ToString());
    sw.WriteLine("=============================================================");
   }
   sw.Flush();
   sw.Close();
   nc.Disconnect();
   
   Console.ReadLine();
  }
}
class NNTPClass:System.Net.Sockets.TcpClient{
  public void Connect(string server){
   string response;

   Connect(server, 119);
   response = Response();
   if (response.Substring( 0, 3) != "200") {
    throw new Exception(response);
   }
   
  }
  public void Disconnect() {
   string message;
   string response;

   message = "QUIT\r\n";
   Write(message);
   response = Response();
   if (response.Substring( 0, 3) != "205") {
    throw new Exception(response);
   }
  }
  public ArrayList GetNewsgroups() {
   string message;
   string response;

   ArrayList retval = new ArrayList();

   message = "LIST\r\n";
   Write(message);
   response = Response();
   if (response.Substring( 0, 3) != "215") {
    throw new Exception(response);
   }

   while (true) {
    response = Response();
    if (response == ".\r\n" ||
     response == ".\n") {
     return retval;
    }
    else {
     char[] seps = { ' ' };
     string[] values = response.Split(seps);
     retval.Add(values[0]);
     continue;
    }
   }
  }
  public void Post(string newsgroup, string subject, string from,
   string content) {
   string message;
   string response;

   message = "POST " + newsgroup + "\r\n";
   Write(message);
   response = Response();
   if (response.Substring( 0, 3) != "340") {
    throw new Exception(response);
   }

   message = "From: " + from + "\r\n"
    + "Newsgroups: " + newsgroup + "\r\n"
    + "Subject: " + subject + "\r\n\r\n"
    + content + "\r\n.\r\n";

   Write(message);
   response = Response();
   if (response.Substring( 0, 3) != "240") {
    throw new Exception(response);
   }
  }

  public ArrayList GetNews(string newsgroup) {
   string message;
   string response;

   ArrayList retval = new ArrayList();

   message = "GROUP " + newsgroup + "\r\n";
   Write(message);
   response = Response();
   if (response.Substring( 0, 3) != "211") {
    throw new Exception(response);
   }

   char[] seps = { ' ' };
   string[] values = response.Split(seps);

   long start = Int32.Parse(values[2]);
   long end = Int32.Parse(values[3]);

   if (start+100 < end && end > 100) {
    start = end-100;
   }

   for (long i=start;i<end;i++) {
    message = "ARTICLE " + i + "\r\n";
    Write(message);
    response = Response();
    if (response.Substring( 0, 3) == "423") {
     continue;
    }
    if (response.Substring( 0, 3) != "220") {
     throw new Exception(response);
    }

    string article = "";
    while (true) {
     response = Response();
     if (response == ".\r\n") {
      break;
     }

     if (response == ".\n") {
      break;
     }
        
     if (article.Length < 1024) {
      article += response;
     };
    }

    retval.Add(article);
   }

   return retval;
  }

  private string Response() {
   //System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
   System.Text.Encoding enc=Encoding.Default;
   byte []serverbuff = new Byte[1024];
   NetworkStream stream = GetStream();
   int count = 0;
   while (true) {
    byte []buff = new Byte[2];
    int bytes = stream.Read( buff, 0, 1 );
    if (bytes == 1) {
     serverbuff[count] = buff[0];
     count++;

     if (buff[0] == '\n') {
      break;
     }
    }
    else {
     break;
    };
   };

   string retval = enc.GetString( serverbuff, 0, count );
   System.Diagnostics.Debug.WriteLine("READ:" + retval);
   return retval;
  }

  private void Write(string message) {
   System.Text.ASCIIEncoding en = new System.Text.ASCIIEncoding() ;

   byte[] WriteBuffer = new byte[1024] ;
   WriteBuffer = en.GetBytes(message) ;

   NetworkStream stream = GetStream() ;
   stream.Write(WriteBuffer,0,WriteBuffer.Length);

   System.Diagnostics.Debug.WriteLine("WRITE:" + message);
   
   
  }

}
}
}