Client Server help

Talk2Tom11

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Joined
Feb 22, 2004
Messages
144
Location
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I have a program that has two parts. A server and a client. The server is written in C# and the client is written in VB.NET. My question is, I want to know how to have the server send an int back to the client of how many clients are logged into the server. The code for the server is posted below.

Code:
using System;
using System.Threading;								
using System.Net;									
using System.Net.Sockets;							
using System.Collections;							

namespace ChatServer
{

	class AppMain
	{
		
		private ArrayList	m_aryClients = new ArrayList();	// List of Client Connections
		/// <summary>
		/// Application starts here. Create an instance of this class and use it
		/// as the main object.
		/// </summary>
		/// <param name="args"></param>
		static void Main(string[] args)
		{
			AppMain app = new AppMain();
			// Welcome and Start listening
			Console.WriteLine( "*** Chat Server Started {0} *** ", DateTime.Now.ToString( "G" ) );


			/*
			//
			// Method 1
			//
			Socket client;
			const int nPortListen = 399;
			try
			{
				TcpListener listener = new TcpListener( nPortListen );
				Console.WriteLine( "Listening as {0}", listener.LocalEndpoint );
				listener.Start();
				do
				{
					byte [] m_byBuff = new byte[127];
					if( listener.Pending() )
					{
						client = listener.AcceptSocket();
						// Get current date and time.
						DateTime now = DateTime.Now;
						String strDateLine = "Welcome " + now.ToString("G") + "\n\r";

						// Convert to byte array and send.
						Byte[] byteDateLine = System.Text.Encoding.ASCII.GetBytes( strDateLine.ToCharArray() );
						client.Send( byteDateLine, byteDateLine.Length, 0 );
					}
					else
					{
						Thread.Sleep( 100 );
					}
				} while( true );	// Dont use this. 

				//Console.WriteLine ("OK that does it! Screw you guys Im going home..." );
				//listener.Stop();
			}
			catch( Exception ex )
			{
				Console.WriteLine ( ex.Message );
			}
			*/


			//
			// Method 2 
			//
			const int nPortListen = 399;
			// Determine the IPAddress of this machine
			IPAddress [] aryLocalAddr = null;
			String strHostName = "";
			try
			{
				// NOTE: DNS lookups are nice and all but quite time consuming.
				strHostName = Dns.GetHostName();
				IPHostEntry ipEntry = Dns.GetHostByName( strHostName );
				aryLocalAddr = ipEntry.AddressList;
			}
			catch( Exception ex )
			{
				Console.WriteLine ("Error trying to get local address {0} ", ex.Message );
			}
	
			// Verify we got an IP address. Tell the user if we did
			if( aryLocalAddr == null || aryLocalAddr.Length < 1 )
			{
				Console.WriteLine( "Unable to get local address" );
				return;
			}
			Console.WriteLine( "Listening on : [{0}] {1}:{2}", strHostName, aryLocalAddr[0], nPortListen );

			// Create the listener socket in this machines IP address
			Socket listener = new Socket( AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp );
			listener.Bind( new IPEndPoint( aryLocalAddr[0], 399 ) );
			//listener.Bind( new IPEndPoint( IPAddress.Loopback, 399 ) );	// For use with localhost 127.0.0.1
			listener.Listen( 10 );

			// Setup a callback to be notified of connection requests
			listener.BeginAccept( new AsyncCallback( app.OnConnectRequest ), listener );

			Console.WriteLine ("Press Enter to exit" );
			Console.ReadLine();
			Console.WriteLine ("OK that does it! Screw you guys Im going home..." );

			// Clean up before we go home
			listener.Close();
			GC.Collect();
			GC.WaitForPendingFinalizers();		
		}


		/// <summary>
		/// Callback used when a client requests a connection. 
		/// Accpet the connection, adding it to our list and setup to 
		/// accept more connections.
		/// </summary>
		/// <param name="ar"></param>
		public void OnConnectRequest( IAsyncResult ar )
		{
			Socket listener = (Socket)ar.AsyncState;
			NewConnection( listener.EndAccept( ar ) );
			listener.BeginAccept( new AsyncCallback( OnConnectRequest ), listener );
		}

		/// <summary>
		/// Add the given connection to our list of clients
		/// Note we have a new friend
		/// Send a welcome to the new client
		/// Setup a callback to recieve data
		/// </summary>
		/// <param name="sockClient">Connection to keep</param>
		//public void NewConnection( TcpListener listener )
		public void NewConnection( Socket sockClient )
		{
			// Program blocks on Accept() until a client connects.
			//SocketChatClient client = new SocketChatClient( listener.AcceptSocket() );
			SocketChatClient client = new SocketChatClient( sockClient );
			m_aryClients.Add( client );
			Console.WriteLine( "Client {0}, joined", client.Sock.RemoteEndPoint );
 
			// Get current date and time.
			DateTime now = DateTime.Now;
			String strDateLine = "Welcome " + now.ToString("G") + "\n\r";

			// Convert to byte array and send.
			Byte[] byteDateLine = System.Text.Encoding.ASCII.GetBytes( strDateLine.ToCharArray() );
			client.Sock.Send( byteDateLine, byteDateLine.Length, 0 );

			client.SetupRecieveCallback( this );
		}

		/// <summary>
		/// Get the new data and send it out to all other connections. 
		/// Note: If not data was recieved the connection has probably 
		/// died.
		/// </summary>
		/// <param name="ar"></param>
		public void OnRecievedData( IAsyncResult ar )
		{
			SocketChatClient client = (SocketChatClient)ar.AsyncState;
			byte [] aryRet = client.GetRecievedData( ar );

			// If no data was recieved then the connection is probably dead
			if( aryRet.Length < 1 )
			{
				Console.WriteLine( "Client {0}, disconnected", client.Sock.RemoteEndPoint );
				client.Sock.Close();
				m_aryClients.Remove( client );      				
				return;
			}

			// Send the recieved data to all clients (including sender for echo)
			foreach( SocketChatClient clientSend in m_aryClients )
			{
				try
				{
					clientSend.Sock.Send( aryRet );
				}
				catch
				{
					// If the send fails the close the connection
					Console.WriteLine( "Send to client {0} failed", client.Sock.RemoteEndPoint );
					clientSend.Sock.Close();
					m_aryClients.Remove( client );
					return;
				}
			}
			client.SetupRecieveCallback( this );
		}
	}

	/// <summary>
	/// Class holding information and buffers for the Client socket connection
	/// </summary>
	internal class SocketChatClient
	{
		private Socket m_sock;						// Connection to the client
		private byte[] m_byBuff = new byte[50];		// Receive data buffer
		/// <summary>
		/// Constructor
		/// </summary>
		/// <param name="sock">client socket conneciton this object represents</param>
		public SocketChatClient( Socket sock )
		{
			m_sock = sock;
		}

		// Readonly access
		public Socket Sock
		{
			get{ return m_sock; }
		}

		/// <summary>
		/// Setup the callback for recieved data and loss of conneciton
		/// </summary>
		/// <param name="app"></param>
		public void SetupRecieveCallback( AppMain app )
		{
			try
			{
				AsyncCallback recieveData = new AsyncCallback(app.OnRecievedData);
				m_sock.BeginReceive( m_byBuff, 0, m_byBuff.Length, SocketFlags.None, recieveData, this );
			}
			catch( Exception ex )
			{
				Console.WriteLine( "Recieve callback setup failed! {0}", ex.Message );
			}
		}

		/// <summary>
		/// Data has been recieved so we shall put it in an array and
		/// return it.
		/// </summary>
		/// <param name="ar"></param>
		/// <returns>Array of bytes containing the received data</returns>
		public byte [] GetRecievedData( IAsyncResult ar )
		{
            int nBytesRec = 0;
			try
			{
				nBytesRec = m_sock.EndReceive( ar );
			}
			catch{}
			byte [] byReturn = new byte[nBytesRec];
			Array.Copy( m_byBuff, byReturn, nBytesRec );
			
			/*
			// Check for any remaining data and display it
			// This will improve performance for large packets 
			// but adds nothing to readability and is not essential
			int nToBeRead = m_sock.Available;
			if( nToBeRead > 0 )
			{
				byte [] byData = new byte[nToBeRead];
				m_sock.Receive( byData );
				// Append byData to byReturn here
			}
			*/
			return byReturn;
		}
	}
}

if anyone has any idea how to do this... please post
 
HJB417 said:
I would use the BitConverter class to convert an int to a 4byte array and send this over the wire. The when and where it is sent, you, the implementer, must decide.


I understand what you mean... but I am not sure how to write the code for it. I want to display this number of users in a label on the client version called lblusers.
 
and when should the value of this label get updated?
whenever a message is received?
when you 1st connect?
every X seconds?
 
HJB417 said:
and when should the value of this label get updated?
whenever a message is received?
when you 1st connect?
every X seconds?

It should be updated everytime a new user logs in and everytime a user logs off
 
youre going to need to write a well defined protocol (first logically/on paper and then in code) if you wanna do it right.
 

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