class Program     {         static void Main(string[] args)         {             TcpListener lsner = new TcpListener(9000);             lsner.Start();             Console.WriteLine("started in port: 9000");             while (true)             {                 TcpClient client=lsner.AcceptTcpClient();                 Console.WriteLine("new client received. hashcode: {0}", client.GetHashCode());                 ThreadPool.QueueUserWorkItem(new WaitCallback(ProcessTcpClient), client);             }             Console.ReadKey();         }         private static void ProcessTcpClient(object state)         {             TcpClient client=state as TcpClient;             if(client==null)                 Console.WriteLine("client is null");             NetworkStream ns=client.GetStream();             StreamWriter sw = new StreamWriter(ns);             sw.WriteLine("Welcome.");             sw.Flush();             sw.Close();             client.Close();         }

class Program     {         static void Main(string[] args)         {             IPAddress address = IPAddress.Parse("127.0.0.1");             IPEndPoint ep=new IPEndPoint(address, 9000);             TcpClient client = new TcpClient();             client.Connect(ep);             NetworkStream ns=client.GetStream();             StreamReader sr = new StreamReader(ns);             Console.WriteLine(sr.ReadToEnd());             sr.Close();             sr.Dispose();             ns.Close();             ns.Dispose();             client.Close();             Console.ReadKey();         }     }