Stop a Asyncronous TCP Application Properly

Hi i have a disconnect button click event in my SERVER application as follows.Before it dc, it will alert other clients by sending a "/exit" command.After that it will shutdown its connection.

 private void stopBu开发者_开发问答tton_Click(object sender, EventArgs e)
    {
        byte[] exit_command = Encoding.ASCII.GetBytes("/exit");
        g_server_conn.BeginSend(exit_command, 0, exit_command.Length, SocketFlags.None, new AsyncCallback(Send), g_server_conn);
        g_server_conn.Shutdown(SocketShutdown.Both);
        g_server_conn.Close();
    }

The problem is that the server is executing Socket.BeginRecieve() method all the time. How do we tell the begin recieve method to stop its operation so that i can close properly.

private void Accept(IAsyncResult iar) {

        Socket winsock = (Socket)iar.AsyncState;
        g_server_conn = winsock.EndAccept(iar);


        //Function that exchanges names of each other
        NewClient(g_server_conn);

        Socket server_conn = g_server_conn;

        chat_msg = new byte[1024];
        server_conn.BeginReceive(chat_msg, 0, chat_msg.Length, SocketFlags.None, new AsyncCallback(Recieve), server_conn);

    }

    private void Recieve(IAsyncResult iar)
    {
        Socket server_conn = (Socket)iar.AsyncState;
        server_conn.EndReceive(iar);

        //If clients shutdown connection,Server recieves /exit command
        if (Encoding.ASCII.GetString(chat_msg, 0, chat_msg.Length) == "/exit")
        {
            g_server_conn.Shutdown(SocketShutdown.Both);
            g_server_conn.Close();
            return;
        }
        SetLabel(client_name, chatListBox);
        SetLabel(Encoding.ASCII.GetString(chat_msg), chatListBox);

        chat_msg = new byte[1024];
        server_conn.BeginReceive(chat_msg, 0, chat_msg.Length, SocketFlags.None, new AsyncCallback(Recieve), server_conn);


    }

You should use the IAsyncResult returned by the BeginXXX methods. IIRC, you can dispose of the WaitHandle.

Does the clients realy need to know why the server closed the connection(You seem to send a disconnect message with no reason information anyways,)? It seems your just sending a extra message to the clients to disconnect them.

You can just disconnect all the clients, and they will recive a close socket message, this will on the client side show the connection being closed.

On a side note, there is no point in converting the recived string so many times, convert it once from byte array to string and your done :).

Personaly the order i would do it is:
1)Set a global bool, that we are no longer accepting new clients ( IE if a new client tries to connect in this time, i would not accept it)
2)Go over the client list an and disconnect them
3)Shut downt he lister.