Question

Im trying to send some object from a server to the client.
My problem is that when im sending only 1 object, everything works correctly. But at the moment i add another object an exception is thrown – “binary stream does not contain a valid binaryheader” or “No map for object (random number)”.
My thoughts are that the deserialization does not understand where the stream starts / ends and i hoped that you guys can help me out here.

heres my deserialization code:

public void Listen()
        {
            try
            {
                bool offline = true;
                Dispatcher.Invoke(System.Windows.Threading.DispatcherPriority.Normal,
                    new Action(() => offline = Offline));
                while (!offline)
                {
                    TcpObject tcpObject = new TcpObject();
                    IFormatter formatter = new BinaryFormatter();
                    tcpObject = (TcpObject)formatter.Deserialize(serverStream);

                    if (tcpObject.Command == Command.Transfer)
                    {
                        SentAntenna sentAntenna = (SentAntenna)tcpObject.Object;

                        int idx = 0;
                        foreach (string name in SharedProperties.AntennaNames)
                        {
                            if (name == sentAntenna.Name)
                                break;
                            idx++;
                        }

                        if (idx < 9)
                        {
                            PointCollection pointCollection = new PointCollection();
                            foreach (Frequency f in sentAntenna.Frequencies)
                                pointCollection.Add(new Point(f.Channel, f.Intensity));

                            SharedProperties.AntennaPoints[idx] = pointCollection;
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message); // raise an event
            }
        }

serialization code:

case Command.Transfer:
                            Console.WriteLine("Transfering");
                            Thread transfer = new Thread(new ThreadStart(delegate
                            {
                                try
                                {
                                    string aName = tcpObject.Object.ToString();
                                    int indx = 0;
                                    foreach (string name in names)
                                    {
                                        if (name == aName)
                                            break;
                                        indx++;
                                    }

                                    if (indx < 9)
                                    {
                                        while (true) // need to kill when the father thread terminates
                                        {
                                            if (antennas[indx].Frequencies != null)
                                            {
                                                lock (antennas[indx].Frequencies)
                                                {
                                                    TcpObject sendTcpObject = new TcpObject();
                                                    sendTcpObject.Command = Command.Transfer;
                                                    SentAntenna sa = new SentAntenna(antennas[indx].Frequencies, aName);
                                                    sendTcpObject.Object = sa;
                                                    formatter.Serialize(networkStream, sendTcpObject);
                                                }
                                            }
                                        }
                                    }
                                }
                                catch (Exception ex) { Console.WriteLine(ex); }
                            }));
                            transfer.Start();
                            break;

Answer 1

apperantly i came up with a really simple solution. I just made sure only 1 thread is allowed to transfer data at the same time so i changed this line of code:

formatter.Serialize(networkStream, sendTcpObject);

to these lines of code:

if (!transfering) // making sure only 1 thread is transfering data
{
    transfering = true;
    formatter.Serialize(networkStream, sendTcpObject);
    transfering = false;
}