Question

i make a simple TCP client/server in C# and i have the problem. When i test my code with telnet, the server is reading the socket fine and wrote the result. But when my client is writting a sentence on the socket, the server is block at the readLine function.

Here you have my client :

 public Boolean initConnection(String ip)
        {
            try
            {
              this.client.Connect("127.0.0.1", 40000);
              this.output = this.client.GetStream();
              this.reader = new StreamReader(this.output, Encoding.UTF8);
              this.writer = new StreamWriter(this.output, Encoding.UTF8);
              writer.Write("one sentence");
              return (true);
            }
          catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                return (false);
            }
        }

and here you have my server :

class SNetwork
    {
        private Thread Tread;
        private TcpListener server;
        private TcpClient client;
        private StreamReader reader;
        private StreamWriter writer;
        private NetworkStream output;
        private State state;

        public void initReading()
        {
            this.server = new TcpListener(IPAddress.Any, 40000);
            output = client.GetStream();
            reader = new StreamReader(output, Encoding.UTF8);
            writer = new StreamWriter(output, Encoding.UTF8);
            this.Tread = new Thread(new ThreadStart(this.read)); // this.Tread is a thread
            this.Tread.Start();
        }

   private void read()
        {
            try
            {
                while (Thread.CurrentThread.IsAlive)
                {
                    String result;

                    if (this.client.Client.Poll(10, SelectMode.SelectRead))
                    {
                        this.state = State.Closed;
                        break;
                    }
                    else
                    {
                        result = reader.ReadLine();
                        if (result != null && result.Length > 0)
                            Console.WriteLine(result);
                    }
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }
        }
}

Anyone can help me plz ? i don’t find a solution

Answer 1

This code:

writer.Write("one sentence");

isn’t writing a line terminator – so your server code doesn’t know that you’ve finished the line. Change it to WriteLine (and flush the writer) it should be okay.

You always need to bear in mind that TCP/IP is a stream-based protocol – you can’t expect the server to receive the data with as many Read calls as you issued Write calls, and if you’re going for a line-terminated protocol on top, you need to make sure you terminate your lines.

(As a separate matter, it would be a good idea to follow .NET naming conventions…)