C#

void comboBox1_KeyPress(object sender, KeyPressEventArgs e)
        {            
            
            
            string str;
            str = comboBox1.Text;   //First time i am getting str empty          
            MessageBox.Show(str);
            
	       

        }

void CTest1View::OnEditchangeCombo1() 
{
        CString strTemp;
	m_ctrlCombo.GetWindowText(strTemp;);
}

public SByte DataValue
        {
            get { return SByte.Parse(this.Text); }
            set { this.Text = value.ToString(); }
        }
        public Int16 DataValue
        {
            get { return Int16.Parse(this.Text); }
            set { this.Text = value.ToString(); }
        }

using System;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Text; 

namespace WindowsApplication1
{
    public partial class Form1 : Form
    {
        System.Net.Sockets.TcpClient clientSocket = new System.Net.Sockets.TcpClient();
        NetworkStream serverStream; 

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            msg("Client Started");
            clientSocket.Connect("127.0.0.1", 8888);
            label1.Text = "Client Socket Program - Server Connected ...";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            NetworkStream serverStream = clientSocket.GetStream();
            byte[] outStream = System.Text.Encoding.ASCII.GetBytes("Message from Client$");
            serverStream.Write(outStream, 0, outStream.Length);
            serverStream.Flush();

            byte[] inStream = new byte[10025];
            serverStream.Read(inStream, 0, (int)clientSocket.ReceiveBufferSize);
            string returndata = System.Text.Encoding.ASCII.GetString(inStream);
            msg("Data from Server : " + returndata);
        }

        public void msg(string mesg)
        {
            textBox1.Text = textBox1.Text + Environment.NewLine + " >> " + mesg;
        } 
    }
}

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            TcpListener serverSocket = new TcpListener(8888);
            TcpClient clientSocket = default(TcpClient);
            int counter = 0;

            serverSocket.Start();
            Console.WriteLine(" >> " + "Server Started"); 

            counter = 0;
            while (true)
            {
                counter += 1;
                clientSocket = serverSocket.AcceptTcpClient();
                Console.WriteLine(" >> " + "Client No:" + Convert.ToString(counter) + " started!");
                handleClinet client = new handleClinet();
                client.startClient(clientSocket, Convert.ToString(counter));
            }

            clientSocket.Close();
            serverSocket.Stop();
            Console.WriteLine(" >> " + "exit");
            Console.ReadLine();
        }
    }

    //Class to handle each client request separatly
    public class handleClinet
    {
        TcpClient clientSocket;
        string clNo;
        public void startClient(TcpClient inClientSocket, string clineNo)
        {
            this.clientSocket = inClientSocket;
            this.clNo = clineNo;
            Thread ctThread = new Thread(doChat);
            ctThread.Start();
        }
        private void doChat()
        {
            int requestCount = 0;
            byte[] bytesFrom = new byte[10025];
            string dataFromClient = null;
            Byte[] sendBytes = null;
            string serverResponse = null;
            string rCount = null;
            requestCount = 0;

            while ((true))
            {
                try
                {
                    requestCount = requestCount + 1;
                    NetworkStream networkStream = clientSocket.GetStream();
                    networkStream.Read(bytesFrom, 0, (int)clientSocket.ReceiveBufferSize);
                    dataFromClient = System.Text.Encoding.ASCII.GetString(bytesFrom);
                    dataFromClient = dataFromClient.Substring(0, dataFromClient.IndexOf("$"));
                    Console.WriteLine(" >> " + "From client-" + clNo + dataFromClient);

                    rCount = Convert.ToString(requestCount);
                    serverResponse = "Server to clinet(" + clNo + ") " + rCount;
                    sendBytes = Encoding.ASCII.GetBytes(serverResponse);
                    networkStream.Write(sendBytes, 0, sendBytes.Length);
                    networkStream.Flush();
                    Console.WriteLine(" >> " + serverResponse);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(" >> " + ex.ToString());
                }
            }
        }
    } 
}