Tcp Char 2 : Chat : Network C# Examples

    
/*
Quote  from  

C#  Network  Programming
#  Paperback:  656  pages
#  Publisher:  Sybex  (November  26,  2002)
#  Language:  English
#  ISBN-10:  0782141765
#  ISBN-13:  978-0782141764
*/

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


class  NewTcpChat  :  Form
{
      private  static  TextBox  newText;
      private  static  ListBox  results;
      private  static  ListBox  hosts;
      private  static  Socket  client;
      private  static  byte[]  data  =  new  byte[1024];

      public  NewTcpChat()
      {
            Text  =  "New  TCP  Chat  Program";
            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,  10  *  Font.Height);

            Label  label2  =  new  Label();
            label2.Parent  =  this;
            label2.Text  =  "Active  hosts";
            label2.AutoSize  =  true;
            label2.Location  =  new  Point(10,  240);

            hosts  =  new  ListBox();
            hosts.Parent  =  this;
            hosts.Location  =  new  Point(10,  255);
            hosts.Size  =  new  Size(360,  5  *  Font.Height);

            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  listen  =  new  Button();
            listen.Parent  =  this;
            listen.Text  =  "Listen";
            listen.Location  =  new  Point(295,52);
            listen.Size  =  new  Size(6  *  Font.Height,  2  *  Font.Height);
            listen.Click  +=  new  EventHandler(ButtonListenOnClick);

            Thread  fh  =  new  Thread(new  ThreadStart(findHosts));
            fh.IsBackground  =  true;
            fh.Start();
      }

      void  ButtonListenOnClick(object  obj,  EventArgs  ea)
      {
            results.Items.Add("Listening  for  a  client...");
            Socket  newsock  =  new  Socket(AddressFamily.InterNetwork,  SocketType.Stream,  ProtocolType.Tcp);
            IPEndPoint  iep  =  new  IPEndPoint(IPAddress.Any,  9050);
            newsock.Bind(iep);
            newsock.Listen(5);
            newsock.BeginAccept(new  AsyncCallback(AcceptConn),  newsock);
            Thread  advertise  =  new  Thread(new  ThreadStart(srvrAdvertise));
            advertise.IsBackground  =  true;
            advertise.Start();
      }

      void  ButtonConnectOnClick(object  obj,  EventArgs  ea)
      {
            results.Items.Add("Connecting...");
            client  =  new  Socket(AddressFamily.InterNetwork,  SocketType.Stream,  ProtocolType.Tcp);
            string  selectedhost  =  (string)hosts.SelectedItem;
            string[]  hostarray  =  selectedhost.Split(':');
            IPEndPoint  iep  =  new  IPEndPoint(IPAddress.Parse(hostarray[1]),  9050);
            client.BeginConnect(iep,  new  AsyncCallback(Connected),  client);
      }

      void  ButtonSendOnClick(object  obj,  EventArgs  ea)
      {
            byte[]  message  =  Encoding.ASCII.GetBytes(newText.Text);
            newText.Clear();
            client.BeginSend(message,  0,  message.Length,  0,  new  AsyncCallback(SendData),  client);
      }

      void  AcceptConn(IAsyncResult  iar)
      {
            Socket  oldserver  =  (Socket)iar.AsyncState;
            client  =  oldserver.EndAccept(iar);
            results.Items.Add("Connection  from:  "  +  client.RemoteEndPoint.ToString());
            Thread  receiver  =  new  Thread(new  ThreadStart(ReceiveData));
            receiver.IsBackground  =  true;
            receiver.Start();
      }

      void  Connected(IAsyncResult  iar)
      {
            try
            {
                  client.EndConnect(iar);
                  results.Items.Add("Connected  to:  "  +  client.RemoteEndPoint.ToString());
                  Thread  receiver  =  new  Thread(new  ThreadStart(ReceiveData));
                  receiver.IsBackground  =  true;
                  receiver.Start();

            }  catch  (SocketException)
            {
                  results.Items.Add("Error  connecting");
            }
      }

      void  SendData(IAsyncResult  iar)
      {
            Socket  remote  =  (Socket)iar.AsyncState;
            int  sent  =  remote.EndSend(iar);
      }

      void  ReceiveData()
      {
            int  recv;
            string  stringData;
            while  (true)
            {
                  recv  =  client.Receive(data);
                  stringData  =  Encoding.ASCII.GetString(data,  0,  recv);
                  if  (stringData  ==  "bye")
                        break;
                  results.Items.Add(stringData);
            }
            stringData  =  "bye";
            byte[]  message  =  Encoding.ASCII.GetBytes(stringData);
            client.Send(message);
            client.Close();
            results.Items.Add("Connection  stopped");
            return;
      }

      void  srvrAdvertise()
      {
            Socket  server  =  new  Socket(AddressFamily.InterNetwork,  SocketType.Dgram,  ProtocolType.Udp);
            server.SetSocketOption(SocketOptionLevel.Socket,  SocketOptionName.Broadcast,  1);
            IPEndPoint  iep  =  new  IPEndPoint(IPAddress.Broadcast,  9051);
            byte[]  hostname  =  Encoding.ASCII.GetBytes(Dns.GetHostName());
            while  (true)
            {
                  server.SendTo(hostname,  iep);
                  Thread.Sleep(60000);
            }
      }

      void  findHosts()
      {
            while(true)
            {
                  Socket  remoteHosts  =  new  Socket(AddressFamily.InterNetwork,  SocketType.Dgram,  ProtocolType.Udp);
                  IPEndPoint  iep  =  new  IPEndPoint(IPAddress.Any,  9051);
                  EndPoint  ep  =  (EndPoint)iep;
                  remoteHosts.Bind(iep);
                  byte[]  data  =  new  byte[1024];
                  int  recv  =  remoteHosts.ReceiveFrom(data,  ref  ep);
                  string  stringData  =  Encoding.ASCII.GetString(data,  0,  recv);
                  string  entry  =  stringData  +  ":"  +  ep.ToString();
                  if  (!hosts.Items.Contains(entry))
                        hosts.Items.Add(entry);
            }
      }

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