Async Tcp Server : TCP Server : Network C# Source Code

    

/*
C# Network Programming 
by Richard Blum

Publisher: Sybex 
ISBN: 0782141765
*/

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


public class AsyncTcpSrvr : Form
{
   private TextBox conStatus;
   private ListBox results;
   private byte[] data = new byte[1024];
   private int size = 1024;
   private Socket server;


   public AsyncTcpSrvr()
   {
      Text = "Asynchronous TCP Server";
      Size = new Size(400, 380);

      results = new ListBox();
      results.Parent = this;
      results.Location = new Point(10, 65);
      results.Size = new Size(350, 20 * Font.Height);

      Label label1 = new Label();
      label1.Parent = this;
      label1.Text = "Text received from client:";
      label1.AutoSize = true;
      label1.Location = new Point(10, 45);

      Label label2 = new Label();
      label2.Parent = this;
      label2.Text = "Connection Status:";
      label2.AutoSize = true;
      label2.Location = new Point(10, 330);

      conStatus = new TextBox();
      conStatus.Parent = this;
      conStatus.Text = "Waiting for client...";
      conStatus.Size = new Size(200, 2 * Font.Height);
      conStatus.Location = new Point(110, 325);

      Button stopServer = new Button();
      stopServer.Parent = this;
      stopServer.Text = "Stop Server";
      stopServer.Location = new Point(260,32);
      stopServer.Size = new Size(7 * Font.Height, 2 * Font.Height);
      stopServer.Click += new EventHandler(ButtonStopOnClick);

      server = new Socket(AddressFamily.InterNetwork,
                    SocketType.Stream, ProtocolType.Tcp);
      IPEndPoint iep = new IPEndPoint(IPAddress.Any, 9050);
      server.Bind(iep);
      server.Listen(5);
      server.BeginAccept(new AsyncCallback(AcceptConn), server);
   }

   void ButtonStopOnClick(object obj, EventArgs ea)
   {
      Close();
   }

   void AcceptConn(IAsyncResult iar)
   {
      Socket oldserver = (Socket)iar.AsyncState;
      Socket client = oldserver.EndAccept(iar);
      conStatus.Text = "Connected to: " + client.RemoteEndPoint.ToString();
      string stringData = "Welcome to my server";
      byte[] message1 = Encoding.ASCII.GetBytes(stringData);
      client.BeginSend(message1, 0, message1.Length, SocketFlags.None,
                  new AsyncCallback(SendData), client);
   }

   void SendData(IAsyncResult iar)
   {
      Socket client = (Socket)iar.AsyncState;
      int sent = client.EndSend(iar);
      client.BeginReceive(data, 0, size, SocketFlags.None,
                  new AsyncCallback(ReceiveData), client);
   }

   void ReceiveData(IAsyncResult iar)
   {
      Socket client = (Socket)iar.AsyncState;
      int recv = client.EndReceive(iar);
      if (recv == 0)
      {
         client.Close();
         conStatus.Text = "Waiting for client...";
         server.BeginAccept(new AsyncCallback(AcceptConn), server);
         return;
      }
      string receivedData = Encoding.ASCII.GetString(data, 0, recv);
      results.Items.Add(receivedData);
      byte[] message2 = Encoding.ASCII.GetBytes(receivedData);
      client.BeginSend(message2, 0, message2.Length, SocketFlags.None,
                   new AsyncCallback(SendData), client);
   }

   public static void Main()
   {
      Application.Run(new AsyncTcpSrvr());
   }
}