Question

I’m not able to connect a simple client and a simple server. When I run the server there doesn’t seem to be any problem, but when I try to send it data with the client it throws an exception saying that it didn’t connect within a timeout period.

Here is the server code I’m using:

    public void server()
    {
        try
        {
            byte[] bytes = new byte[1024];
            int bytesReceived = 0;
            String message = "";
            IPAddress direction = IPAddress.Parse(getIPExternal()); //getIPExternal return the public IP of the machine in which the programm runs
            IPEndPoint directionPort = new IPEndPoint(direction, 5656);
            Socket socketServer = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            socketServer.Bind(directionPort);
            socketServer.Listen(100);
            while (true)
            {
                Socket client = socketServer.Accept();
                bytesReceived = client.Receive(bytes);
                message = System.Text.Encoding.Unicode.GetString(bytes, 0, bytesReceived);

                editMultiline.Invoke(new writeMessageDelegate(writeMessage), new object[] { message, "client"}); //Ignore this, it is just to show the info in a textbox because the server code runs in a diferent thread

                client.Shutdown(SocketShutdown.Both);
                client.Close();
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Server error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

This way I get the public IP from the machine on which the program runs:

    public string getIPExternal()
    {
        string direction;
        WebRequest request = WebRequest.Create("http://checkip.dyndns.org/");
        WebResponse response = request.GetResponse();
        StreamReader stream = new StreamReader(response.GetResponseStream());
        direction = stream.ReadToEnd();
        stream.Close();
        response.Close();

        //Search for the ip in the html
        int first = direction.IndexOf("Address: ") + 9;
        int last = direction.LastIndexOf("</body>");
        direction = direction.Substring(first, last - first);

        return direction;
    }

And here is my client code:

    public void client(string directionIP, string message) //directionIP is the IP from the computer to which i want to get connected
    {
        try
        {
            byte[] bytesSend = System.Text.Encoding.Unicode.GetBytes(message);
            IPAddress direction = IPAddress.Parse(directionIP);
            IPEndPoint directionPort = new IPEndPoint(direction, 5656);
            Socket socketClient = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            socketClient.Connect(directionPort);
            socketClient.Send(bytesSend);
            socketClient.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message, "Client error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

Any suggestion would be great.

Answer 1

Id suggest looking into the TcpListener and TcpClient class, instead of playing around with sockets.. the Tcp* class’s do all that stuff for you