MultiThreadTCP/MultiThreadTCPServer/Server.cs

using System.Net;
using System.Net.Sockets;
using System.Text;

namespace MultiThreadTCPServer
{
    class Server
    {
        TcpListener _server = null;

        public Server(string ip, int port)
        {
            IPAddress localAddr = IPAddress.Parse(ip);
            _server = new TcpListener(localAddr, port);
            _server.Start();
            StartListener();
        }

        private void StartListener()
        {
            try
            {
                while (true)
                {
                    Console.WriteLine("Waiting for a connection...");
                    TcpClient client = _server.AcceptTcpClient();
                    Console.WriteLine("Connected!");

                    Thread t = new Thread(new ParameterizedThreadStart(HandleClient));
                    t.Start();
                }
            }
            catch (SocketException e)
            {
                Console.WriteLine("SocketException: {0}", e);
                _server.Stop();
            }
        }

        private void HandleClient(object? obj)
        {
            TcpClient client = (TcpClient)obj;
            var stream = client.GetStream();

            string imei = String.Empty;

            string data = String.Empty;

            Byte[] bytes = new Byte[256];
            int i;

            try
            {
                while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
                {
                    string hex = BitConverter.ToString(bytes);
                    data = Encoding.ASCII.GetString(bytes, 0, i);
                    Console.WriteLine($"{data}: Received: {Thread.CurrentThread.ManagedThreadId}");

                    string str = "Hey Client!";
                    Byte[] reply = System.Text.Encoding.ASCII.GetBytes(str);
                    stream.Write(reply, 0, reply.Length);
                    Console.WriteLine($"{Thread.CurrentThread.ManagedThreadId}: Sent: {str}");
                }
                     
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception: {0}", e.ToString());
                client.Close();
            }
        }
    }
}