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

namespace ConnectPort
{
    class Program
    {
        static void Main(string[] args)
        {
            int port = 9999;
            IPEndPoint ipEnd = new IPEndPoint(IPAddress.Any, port);
            Console.WriteLine(">>>  Server Start On Port "+ port);
            Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
            sock.Bind(ipEnd);
            sock.Listen(100);
            Socket clientSock = sock.Accept();
            byte[] clientData = new byte[1024];
            int receivedBytesLen;
            Console.WriteLine(">>>  Accept Client");
            Console.WriteLine();
            receivedBytesLen = clientSock.Receive(clientData);
            string clientDataInString = Encoding.ASCII.GetString(clientData, 0, receivedBytesLen);
            Console.WriteLine("Received Data {0}", clientDataInString);
            while(clientSock.Connected)
            {
                try
                {
                    string clientStr = "Client Data Received";
                    byte[] sendData = new byte[1024];
                    sendData = Encoding.ASCII.GetBytes(clientStr);
                    clientSock.Send(sendData);
                }
                catch
                {
                }
                sock.Close();
            }
            clientSock.Close();
            Console.WriteLine(">>>  Exit!");
            Console.ReadLine();
        }
    }
}