TcpListener is not receiving any data

Question

i have an issue where im not receiving any bytes from the connected TcpClient!

Server: (i attempt to add the received message into a listbox, but nothing comes out.

   //tl is a TcpListener
   //I set this up in a 500 milisecond loop. No worries about that.
   if (tl.Pending())
   {
     TcpClient tcp = tl.AcceptTcpClient();
     var s = tcp.GetStream();
     int bytesRead = s.Read(new byte[tcp.ReceiveBufferSize], 0, 
     tcp.ReceiveBufferSize);
     string dataReceived = Encoding.ASCII.GetString(new 
     byte[tcp.ReceiveBufferSize], 0, bytesRead);
     listBox1.Items.Add(dataReceived);
     tcp.Close();
     oac++; //Overall connection count
     label3.Text = "Overall Connections: " + oac; //logging connections
   }

Client:

 void Send(){
    TcpClient c = new TcpClient(Im not including my ip., 4444);
    System.IO.StreamWriter w = new System.IO.StreamWriter(c.GetStream());
    byte[] bytesToSend = ASCIIEncoding.ASCII.GetBytes($"Username: \"
    {textBox1.Text}\" | Password: \"{textBox2.Text}\"");
    NetworkStream nwStream = c.GetStream();
    nwStream.Write(bytesToSend, 0, bytesToSend.Length);
    nwStream.Flush();
  }

I The connection works, but theres some issues receiving data. it just comes out blank

You create your dataReceived string using byte array (new byte[...]) filled with 0, so it is always empty. And you read data from socket to another byte array which is immediately discarded — Evk, Nov 07 '17 at 20:41

score 0 · Accepted Answer · answered Nov 07 '17 at 20:41

0

On serverside, your problem is that you renew toy byte array new byte[tcp.ReceiveBufferSize]. You could also do something like this:

using( var inputStream = new MemoryStream() )
{
  tcp.GetStream().CopyTo(inputStream);
  Encoding.ASCII.GetString(inputStream.ToArray());
  listBox1.Items.Add(dataReceived);
  ...
}

Remember using on all IDisposable's, else you will run out of resources.

answered Nov 07 '17 at 20:41

Frank Nielsen

1,546
1
10
17

System.IO.IOException: 'Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.' Uhhh, i get this error, at tcp.GetStream().CopyTo(inputStream); – Doggo123445 Nov 07 '17 at 20:56
Do your close the client? – Frank Nielsen Nov 07 '17 at 20:58
Else take a peek on this https://stackoverflow.com/questions/10182751/server-client-send-receive-simple-text – Frank Nielsen Nov 07 '17 at 21:01
The best would be to serialize an object on the client side, and deserialize it on server side. – Frank Nielsen Nov 07 '17 at 21:12
I didnt close the client Client side. – Doggo123445 Nov 07 '17 at 21:22

TcpListener is not receiving any data

1 Answers1