CODEWITHSUNDEEP
c#socketsnetwork-programming
CybeX
CybeX

Reputation: 2396

c# - networkstream read and write

good day all

I am going over some network programming to implement with a larger application, but for basics, I am creating a simple network chat server client application with the help of this link

what should happen:

When receiving the data from the client, the message box pops up showing a socket connection to my PC ip address with port, but

Problem:

the messagebox which displays the message sent is empty (aka ""), I do not understand what I am doing wrong.

Advice?

had a look at this, but I do not think this is appropriate for my situation network stream with buffers

client (sends data)

        const int _PORT = 80;
        public Form1()
        {
            InitializeComponent();
        }

        private void sendText(string _reciever_ip, string _MESSAGE)
        {
            TcpClient _sender = new TcpClient(_reciever_ip, _PORT);
            try
            {
                Stream s = _sender.GetStream();
                StreamWriter sw = new StreamWriter(s);
                sw.WriteLine(_MESSAGE);
                s.Close();
            }
            catch (Exception x)
            {
                MessageBox.Show(x.ToString());
            }
            _sender.Close();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            sendText(inputT_IP.Text, inputT_Msg.Text);
        }

server (recieves data)

    const int _PORT = 80;

    static List<string> _ipaddress_list = new List<string>();

    public Form1()
    {
        InitializeComponent();
    }

    private void recieveText(string _IPADDRESS)
    {
        //open a listener for a tcp client, to the same for UDp client
        TcpListener _reciever_client = new     TcpListener(IPAddress.Parse(_IPADDRESS), _PORT); //how would you listen for a     connection from any port?
        _reciever_client.Start();
        while (true)
        {
            Socket _listener_socket = _reciever_client.AcceptSocket();
            try
            {
                MessageBox.Show("Recieving from : " +     _listener_socket.RemoteEndPoint.ToString());
                Stream _net_stream = new NetworkStream(_listener_socket);
                StreamReader sr = new StreamReader(_net_stream);
                MessageBox.Show(sr.ReadLine());
                //richTextBox1.AppendText();
            }
            catch (Exception x)
            {
                MessageBox.Show(x.ToString());
            }
            _listener_socket.Close();
        }
    }

    void GetLocalIPAddress()
    {
        var host = Dns.GetHostEntry(Dns.GetHostName());
        foreach (var ip in host.AddressList)
        {
            if (ip.AddressFamily == AddressFamily.InterNetwork)
            {
                _ipaddress_list.Add(ip.ToString());
            }
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        GetLocalIPAddress();
        foreach (string item in _ipaddress_list)
        {
            (new Thread(() => recieveText(item))).Start();
        }
    }

Upvotes: 0

Views: 2336

Answers (1)

Joachim Isaksson
Joachim Isaksson

Reputation: 180867

A StreamWriter buffers writes, so your code;

Stream s = _sender.GetStream();
StreamWriter sw = new StreamWriter(s);
sw.WriteLine(_MESSAGE);
s.Close();

...actually writes to the StreamWriter's in memory buffer and closes the socket before the data has been passed from the StreamWriter to the network.

If you instead close the StreamWriter;

Stream s = _sender.GetStream();
StreamWriter sw = new StreamWriter(s);
sw.WriteLine(_MESSAGE);
sw.Close();

...Close() actually flushes the buffer to the underlying socket, and then closes the underlying socket after the data has been sent.

Upvotes: 3

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