instantchat.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.Threading;
using System.Net.Sockets;
using System.IO;

namespace TCPChat
{
    class Program
    {
        const string localhost = "localhost";
        static readonly Encoding enc = Encoding.Unicode;

        static void Main(string[] args)
        {
            Console.WriteLine("Server or Client? S/C");
            char c = Console.ReadLine()[0];
            switch (c)
            {
                case 'C':
                case 'c':
                    Client();
                    break;
                case 'S':
                case 's':
                    Server();
                    break;
                default:
                    Console.WriteLine("You must die...");
                    Console.ReadLine();
                    break;

            }
        }

        static void Server()
        {
            var ip = Dns.GetHostEntry(localhost).AddressList[0];
            Console.WriteLine("Port? 81-65535 Default 52645");
            ushort port;
            if (!ushort.TryParse(Console.ReadLine(), out port))
                port = 52645;
            var listner = new TcpListener(ip, port);

            listner.Start();
            Console.WriteLine("Start Server {0} {1}", ip, port);

            var nss = new LinkedList<NetworkStream>();

            for (; ; )
            {
                if (listner.Pending())
                {
                    var client = listner.AcceptTcpClient();
                    Console.WriteLine("Connected {0}", client);
                    nss.AddLast(client.GetStream());
                }
                foreach (var ns in nss)
                {
                    if(!ns.DataAvailable) continue;
                    var ms = new MemoryStream();
                    byte[] res = new byte[256];
                    do
                    {
                        int s = ns.Read(res, 0, res.Length);
                        ms.Write(res, 0, s);
                    }
                    while (ns.DataAvailable);
                    var data = ms.ToArray();
                    var text = enc.GetString(data, 0, data.Length);
                    Console.WriteLine(text);
                    foreach (var cns in nss)
                    {
                        if (cns == ns) continue;
                        cns.Write(data, 0, data.Length);
                    }
                }
            }
        }

        static void Client()
        {
            Console.WriteLine("HostName?");
            var host = Console.ReadLine();
            Console.WriteLine("Port? 81-65535 Default 52645");
            ushort port;
            if (!ushort.TryParse(Console.ReadLine(), out port))
                port = 52645;
            var client = new TcpClient(host, port);

            var ns = client.GetStream();

            Thread thread = new Thread(new ThreadStart(new Action(() => {
                for (; ; )
                {
                    var data = enc.GetBytes(Console.ReadLine());
                    ns.Write(data, 0, data.Length);
                }
                
            })));
            thread.Start();

            for (; ; )
            {
                if (!ns.DataAvailable) continue;
                var ms = new MemoryStream();
                byte[] res = new byte[256];
                do
                {
                    int s = ns.Read(res, 0, res.Length);
                    ms.Write(res, 0, s);
                }
                while (ns.DataAvailable);
                var data = ms.ToArray();
                Console.WriteLine(enc.GetString(data, 0, data.Length));
            }
        }
    }
}