Send and receive byte[] in server-client TCP application

Question

I need to send and receive bytes in from my client to server over NetworkStream. I know how to communicate with strings, but now I need to send and receive bytes.

For example, something like that:

static byte[] Receive(NetworkStream netstr)
{
    try
    {
        byte[] recv = new Byte[256];

        int bytes = netstr.Read(recv, 0, recv.Length); //(**This receives the data using the byte method**)
        return recv;
    }
    catch (Exception ex)
    {
        Console.WriteLine("Error!\n" + ex.Message + "\n" + ex.StackTrace);

        return null;
    }



}

static void Send(NetworkStream netstr, byte[] message)
{
    try
    {
        netstr.Write(message, 0, message.Length);
    }
    catch (Exception ex)
    {
        Console.WriteLine("Error!\n" + ex.Message + "\n" + ex.StackTrace);
    }
}

Server:

        private void prejmi_click(object sender, EventArgs e)
        {
            const string IP = "127.0.0.1";
            const ushort PORT = 54321;
            TcpListener listener = new TcpListener(IPAddress.Parse(IP), PORT);
            listener.Start();
            TcpClient client = listener.AcceptTcpClient();
            NetworkStream ns = client.GetStream();

            byte[] data = Receive(ns)

}

Client:

        private void poslji_Click(object sender, EventArgs e)
        {
            const string IP = "127.0.0.1";
            const ushort PORT = 54321;

            TcpClient client = new TcpClient();
            client.Connect(IP, PORT);

            string test="hello";
            byte[] mybyte=Encoding.UTF8.GetBytes(test);
            Send(ns,mybyte);
}

But that is not the propper way to do this, because byte[] data on server side will always have length of 256.

"because byte[] data on server side will always have length of 256" - well yes, but the return value from the Read call tells you how many bytes have actually been read. You're storing that in the bytes variable, but then not doing anything with it... — Jon Skeet

kac26 kac26 · Accepted Answer · 2017-06-02T22:15:03

Thanks, Jon!

 static byte[] Receive(NetworkStream netstr)
        {
            try
            {
                // Buffer to store the response bytes.
                byte[] recv = new Byte[256];

                // Read the first batch of the TcpServer response bytes.
                int bytes = netstr.Read(recv, 0, recv.Length); //(**This receives the data using the byte method**)

                byte[] a = new byte[bytes];

                for(int i = 0; i < bytes; i++)
                {
                    a[i] = recv[i];
                }

                return a;
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error!\n" + ex.Message + "\n" + ex.StackTrace);

                return null;
            }

        }

        static void Send(NetworkStream netstr, byte[] message)
        {
            try
            {
                //byte[] send = Encoding.UTF8.GetBytes(message.ToCharArray(), 0, message.Length);
                netstr.Write(message, 0, message.Length);
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error!\n" + ex.Message + "\n" + ex.StackTrace);
            }
        }

Send and receive byte[] in server-client TCP application

1 Answers