Async Tcp Client

   

/*
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 AsyncTcpClient : Form
{
   private TextBox newText;
   private TextBox conStatus;
   private ListBox results;
   private Socket client;
   private byte[] data = new byte[1024];
   private int size = 1024;

   public AsyncTcpClient()
   {
      Text = "Asynchronous TCP Client";
      Size = new Size(400, 380);
      
      Label label1 = new Label();
      label1.Parent = this;
      label1.Text = "Enter text string:";
      label1.AutoSize = true;
      label1.Location = new Point(10, 30);

      newText = new TextBox();
      newText.Parent = this;
      newText.Size = new Size(200, 2 * Font.Height);
      newText.Location = new Point(10, 55);

      results = new ListBox();
      results.Parent = this;
      results.Location = new Point(10, 85);
      results.Size = new Size(360, 18 * Font.Height);

      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 = "Disconnected";
      conStatus.Size = new Size(200, 2 * Font.Height);
      conStatus.Location = new Point(110, 325);

      Button sendit = new Button();
      sendit.Parent = this;
      sendit.Text = "Send";
      sendit.Location = new Point(220,52);
      sendit.Size = new Size(5 * Font.Height, 2 * Font.Height);
      sendit.Click += new EventHandler(ButtonSendOnClick);

      Button connect = new Button();
      connect.Parent = this;
      connect.Text = "Connect";
      connect.Location = new Point(295, 20);
      connect.Size = new Size(6 * Font.Height, 2 * Font.Height);
      connect.Click += new EventHandler(ButtonConnectOnClick);

      Button discon = new Button();
      discon.Parent = this;
      discon.Text = "Disconnect";
      discon.Location = new Point(295,52);
      discon.Size = new Size(6 * Font.Height, 2 * Font.Height);
      discon.Click += new EventHandler(ButtonDisconOnClick);
   }

   void ButtonConnectOnClick(object obj, EventArgs ea)
   {
      conStatus.Text = "Connecting...";
      Socket newsock = new Socket(AddressFamily.InterNetwork,
                            SocketType.Stream, ProtocolType.Tcp);
      IPEndPoint iep = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 9050);
      newsock.BeginConnect(iep, new AsyncCallback(Connected), newsock);
   }

   void ButtonSendOnClick(object obj, EventArgs ea)
   {
      byte[] message = Encoding.ASCII.GetBytes(newText.Text);
      newText.Clear();
      client.BeginSend(message, 0, message.Length, SocketFlags.None,
                   new AsyncCallback(SendData), client);
   }

   void ButtonDisconOnClick(object obj, EventArgs ea)
   {
      client.Close();
      conStatus.Text = "Disconnected";
   }

   void Connected(IAsyncResult iar)
   {
      client = (Socket)iar.AsyncState;
      try
      {
         client.EndConnect(iar);
         conStatus.Text = "Connected to: " + client.RemoteEndPoint.ToString();
         client.BeginReceive(data, 0, size, SocketFlags.None,
                       new AsyncCallback(ReceiveData), client);
      } catch (SocketException)
      {
         conStatus.Text = "Error connecting";
      }
   }

   void ReceiveData(IAsyncResult iar)
   {
      Socket remote = (Socket)iar.AsyncState;
      int recv = remote.EndReceive(iar);
      string stringData = Encoding.ASCII.GetString(data, 0, recv);
      results.Items.Add(stringData);
   }

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

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