A request to send or receive data was disallowed the socket is not connected

Question

I am trying ti print a string to an RFID Printer using sockets. Here is my code. When i call :

Print p = new Print();
p.printToIP();

I get this error: A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied.

Here is my class code:

class Print
{

    public string printerIP { get; set; }
    public int printerPort { get; set; }
    public string myZPL { get; set; }
    private EndPoint ep { get; set; }
    private Socket sock { get; set; }
    private NetworkStream ns { get; set; }
    //private AsyncCallback callbackWrite;

public Print()
{
    printerIP = "127.0.0.1";
    printerPort = 9001;
    myZPL = "AN12345";
}



public void printToIP()
{
    ep = new IPEndPoint(IPAddress.Parse(printerIP), printerPort);
    sock = new Socket(ep.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
    sock.Bind(ep);
    sock.Listen(10);

    try
    {
        sock.Connect(ep);
        ns = new NetworkStream(sock);
        byte[] toSend = Encoding.ASCII.GetBytes(myZPL);
        ns.BeginWrite(toSend, 0, toSend.Length, OnWriteComplete, null);
        ns.Flush(); 
    }
    catch (Exception ex)
    {
        sock.Shutdown(SocketShutdown.Both);
        sock.Close();
    }

}

private void OnWriteComplete(IAsyncResult ar)
{
    NetworkStream thisNS = ns;
    thisNS.EndWrite(ar);
    sock.Shutdown(SocketShutdown.Both);
    sock.Close();
}

score 1 · Answer 1 · answered Mar 26 '14 at 13:28

You get this error because you sent data before your client connected .

 ....
     var res = sock .BeginAccept(AcceptCallback, null);

    }

    private void AcceptCallback(IAsyncResult result)
    {           
        Socket socket = sock .EndAccept(result);           

        while (true)
        {
            sock.BeginReceive(_buffer, 0, _buffer.Length, SocketFlags.None, 
                              new AsyncCallback(ReceiveCallBack), socket);
            _resetEvent.WaitOne();
            _resetEvent.Reset();
        }
    }


    ....

Kas · Answer 2 · 2013-11-12T07:19:32.127

0

You should not use a listner socket to Transfer data, you should use a client socket for send or receive data, Usully listener sockets are used only a receiption. Use a client socket then your problem will be solved.

Here you are creating a Listner socket not a client socket

  sock = new Socket(ep.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
  sock.Bind(ep);
  sock.Listen(10);

The proper way would be to create a new instance of socket and connect it to Endpoints

And IF I were you i wouldn't use Socket class, instead I would use TCPClinet/ TCPListner classes provided by framwork.

For Tcpclinet class that would be like this

System.Net.Sockets.TcpClient clinet = new System.Net.Sockets.TcpClient();
            clinet.Connect(endpoint_object);

For normal Socket class that would be this , So you must use the below code in your case

 Socket clientSock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.IP);
    clientSock.Connect(ipEnd);

edited Nov 12 '13 at 07:19

answered Nov 12 '13 at 07:03

Kas

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..sorry please provide example. – Lucky Luke2 Nov 12 '13 at 07:05
Thanks for this....i used it and get a different error. No connection could be made because the target machine actively refused it 127.0.0.1:9100. Im assuming the port number is wrong. Printer is using USB001 port. But how do i use this as my port number when creating the socket. – Lucky Luke2 Nov 12 '13 at 08:20
what you mean USB001 ? – Kas Nov 12 '13 at 10:05
You get that error because there is not a socket listening for incoming clients on specified ipendpoint. And can you please tell me what you are trying to do ? – Kas Nov 12 '13 at 10:09
@DoobyInc.....USB001 is the virtual usb port that the printer is assigned to in the port tab of properties for that printer. I am trying to print a string to an RFID printer(Printronix SL4M RFID Thermal Transfer Printer ) – Lucky Luke2 Nov 12 '13 at 11:07
I think you need to use Ports not sockets , – Kas Nov 12 '13 at 12:20

A request to send or receive data was disallowed the socket is not connected

2 Answers2