Re: managing multiple socket connections !? - C# Discussion Boards

Mohammad Dayyan wrote:
Would appreciate if you answer the questions.
Thank you.

Mohammad Dayyan wrote:
I'm gonna simulate a small-size robocup soccer[^] with nVidia PhysX & C# ?

This is not a question, it is a statement.

Mohammad Dayyan wrote:
How or where can I start learning that ?

Study the subject at home.

Try asking a real question and maybe, just maybe, you will get some help.

Panic, Chaos, Destruction.
My work here is done.

williamnw wrote:
This is not a question, it is a statement.

Thanks for the errors. You will be a good compiler.

try here[^]. It looks like they have lots of help including documentation and forums.

Badger | [badger,badger,badger,badger...]

Thank you Jimmanuel

i have managed to make a client and server classes for socket comunication, but i have no ideea how to manage multiple clients connecting to the server, i've checked the web and msdn but most exmpales are either too convoluted or use different mechanics than mine, so how do you guys do this ?

rareseu wrote:
i've checked the web and msdn but most exmpales are either too convoluted or use different mechanics than mine

Maybe your mechanism isn't right then? Smile | :)

.

1. The simplest way is creating a thread that will call accept in a loop. For each accepted thread you create new client thread, pass new socket there and voila. Drawback is that you will use 1 socket per connection, so managing a lot of sockets could be expensive. (btw, for each client socket, you can use synchronous operations now).
2. A bit more complicated, but more robust solution is to use asynchrounous communication. Then, foreach connected client, you create him a read buffer, write buffer, supply callbacks methods and just invoke BeginRead/Write. Your callbacks methods will be ran automatically when some data will arive (read) or was sent (write). In callback methods, what you should do is call EndRead/Write to get data, do some quick processing (fe. copy received data to some external buffer) and invoke Begin methods once again, and so on, and so on Smile | :)

.

Thanks for the suggestions Ravadre Smile | :)

I've got a question about the 2nd method and in fat this is the main thing i don't understand about working with sockets : how can i tell who i'm talking to ? (client wise) I mean if i accept a connection how do i know who's trying to connect to me ?

I'm not sure if I understand your question correctly. If you meant that you don't know who has just connected to your server - well, you don't Smile | :)

, You can get his IP, or authentificate him using some sort of your own protocol. But if you would have meant that, then this is general issue, not only related to 2nd method, so maybe you've meant, how to know which client has sent you some data, which invoked your callback method, well, there are 2 ways to keep this information; when you Invoke BeginRead() you can pass your own parameter, you can pass some sort of structure that will tell you what you need to know, fe.:

<br />
tcpClient.GetStream().BeginRead(buffer, 0, bufferSize, callback, this)<br />

then, in callback:

<br />
TcpClient myClient = (TcpClient)result.AsyncState;<br />

The second approach (which I use) is to create some sort of wrapper class that handles everything, a little example (a bit simplified):

public class Program
	{
		class NetClient
		{
			const int bufferSize = 4096;
			TcpClient client;
			byte[] writeBuffer;
			byte[] readBuffer;

			public NetClient(TcpClient client)
			{
				this.client = client;
				writeBuffer = new byte[bufferSize];
				readBuffer = new byte[bufferSize];

				client.GetStream().BeginRead(readBuffer, 0, bufferSize, OnDataRead, null);
			}

			void OnDataRead(IAsyncResult result)
			{
				int dataRead = client.GetStream().EndRead(result);

				//...

				client.GetStream().BeginRead(readBuffer, 0, bufferSize, OnDataRead, client);
			}
		}


		public static void Main()
		{
			List<NetClient> clients = new List<NetClient>();

			TcpListener server = new TcpListener(11111);

			server.Start();

			while (true)
			{
				TcpClient client = server.AcceptTcpClient();
				Console.WriteLine((client.Client.RemoteEndPoint as IPEndPoint).Address);
				clients.Add(new NetClient(client));
			}
		}
}

Alternatively, you could make OnDataRead static, and pass NetClient as a parameter, just like in 1st approach.

Thanks for taking the time to explain Ravadre Smile | :)

, i really appreciate it, i'm gonna need some research time to understand the classes and methods you're using. I guess the reason i'm being a little vague with my questions is because i'm not quite sure what i need to make this work, this is the first time i'm working with sockets under c# ( done it once before in c under linux )

Hi Peoples,

i need to check that in a folder a file type of xml ,

that is *.xml

for a single file we use to check like

normally we do like,

folderpath

System.IO.File.Exists(D:\CodeProject\CodeProject.xml)
this will work, but i need to check all the xml file in that folder,
how to do that, can any one help me?

Directory.GetFiles[^]

string []files = Directory.GetFiles("C:\\", "*.xml");

thanks mr jimmanuvel,

actually i need to delete all the xml file in a directory if exists..
ur code will give me the xml directoris in that directory..

so, i have to loop through or is there anyoption for deleting all the xml files in a directory at one stretch??

just loop through the files. .Net doesn't have a built in function for everything Smile | :)

thanks jim

you're welcome

Dear All,

I developed an application and I would like to install it on one computer in a network and want other users in the network to run this application without need to install this app. in all machines.

and for your info:
1. My application requires other application called (Exceed) need to be installed in all machines in order to run my application. (this is out of scope. this application must be installed in all machines).
2. this (Exceed) application stores its path location in a user environment variable in a user machine.
3. my application need to read this Env. variable to locate the (Exceed) application in user machines.

and my goal for that is to make it easy if I would like to release a new version of my application so all what I need to do is to re-install this version in that computer without need to re-install it in all machines in the network.

so is there a way to do that?

I hope this explaination is clear Smile | :)

... and I apprieciate your helps

thanks,

First up, your post is as clear as mud. But luckily I had one over the eight for lunch so understand you.
I'd suggest a slightly different approach. Unless you actually NEED to run your app over the network then DON'T.

Write a very simple bootstrap. All it does is start up and check the installed version against the server, if they're different then it installs the new version. This gets around your problem of needing to propagate new versions manually.

Panic, Chaos, Destruction.
My work here is done.

It's possible to do, but not very nice. Managed code running from a non-local (i.e.: Network) source is not trusted by default. You'll have to go to each machine (or do through policy if your on Active Directory) and configure the .NET Framework to trust the source location of the code, or trust any code that is signed with a certain certificate that you provide. Read up on Code Access Security for all the details (and there is a lot of it!).

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Hi,

am creating appconfig file dynamically to my application folder.
it is working fine but while am uninstalling my application, everything unstalled but that appconfig not uninstalled why this is happening?
how can i uninstall appconfig also?

Thanks InAdvance

The logic seems to be clear, uninstall removes all it knows about, if you create the config file manually how is the uninstaller gong to know about it? Try including an empty config file in the project and edit it, I'm betting the uninstall will find it then.

Never underestimate the power of human stupidity
RAH

yes, you are correct.

cant we delete that app.config file during uninstallation?

HOW CAN WORK WITH MULTI PROCESS?

what is your problem exactly?

By switching between the processes. Why are you shouting, and what are you trying to achieve?

I are troll Smile | :)

Hy guys ! i've been trying to write up classes for a server and a client using sockets, i'm having a bit of a problem with the server : whenever i try to read incoming messages or send messages i get "Object reference not set to an instance of an object" error, this is because my streamWriter/Reader is null. My problem is that i can't figure out why they are null!? when i instance them there are no problems, but when i invoke their mothods they're null Hmmm | :|

, does anybody have any ideeas ?

some code snippets might help to clear this up :

the declarations :

class Server
   {
       private TcpListener listner;

       private Socket socketForClients;

       private System.IO.StreamReader messageReader;
       private System.IO.StreamWriter messageWriter;

the instantianion :

public void startSever()
        {
            
           // listenning for incoming connections
            listner.Start();
          
           //create the socket for the clients
            socketForClients = listner.AcceptSocket();
       
            if (socketPentruClienti.Connected == true)
            {
                try
                {
                    NetworkStream networkStream = new NetworkStream(socketForClients);
                    System.IO.StreamWriter messageWriter = new System.IO.StreamWriter(networkStream);
                    System.IO.StreamReader messageReader = new System.IO.StreamReader(networkStream);
                }
                catch (Exception eNetworkStream)
                {
                    System.Windows.Forms.MessageBox.Show("EROARE : eroare la network stream\nEXCEPTIE : "+eNetworkStream.Message);
                }// try/catch

            }// if connected

        }//startServer

the invoking :

public void write(string message)
        {
            try
            {
                messageWriter.WriteLine(message);
                messageWriter.Flush();
            }
            catch (Exception eScriere)
            {
                System.Windows.Forms.MessageBox.Show("EROARE : serverul nu a putut trimite mesaj\nEXCEPTIE : " + eScriere.Message);
                return;
            }
        }//write

PS : some of the text is in romanian but it's nothing important