I have been having some difficulty in a C# application that uses a UDP socket connection. Everything works all sorts of fancy and fun until the closing of my Form application, and then I can't seem to stop receiving messages.

I always get some form of exception inside of the receive callback stating that the socket is disposed. This is, of course, true. The problem is, why am I getting a message after I have closed down and shutdown the sockets? I'm not too familiar with every in and out of C# (don't think I'll ever get used to managed code. Can I have C back?) Included, I have the receive callback, which parses a message and continues to listen. I also included the CloseConnections method, which is called within the Form Closing event.

Does Shutdown and Close not stop the messages from being received? If so, how can I so that the GC may dispose of my sockets without receiving a message afterwards?

"An unhandled exception of type 'System.ObjectDisposedException' occurred in system.dll
Additional information: Cannot access a disposed object named "System.Net.Sockets.Socket"."


private static void ReceiveCallback(IAsyncResult ar)
{
// End Receive
StateObject stateObject = (StateObject)ar.AsyncState;

if(stateObject != null && stateObject.Socket != null && stateObject.DataBuffer != null && stateObject.EventMap != null)
{
int bytesReceived = stateObject.Socket.EndReceive(ar);

if(bytesReceived > 0)
{
// Parse Data
SocketConnection.ParseReceiveBuffer(stateObject);
}
}
if(stateObject != null && stateObject.Socket != null && stateObject.DataBuffer != null && stateObject.EventMap != null)
{
// Begin Receive
stateObject.Socket.BeginReceive(stateObject.DataBuffer, 0, stateObject.BufferSize, 0, new AsyncCallback(ReceiveCallback), stateObject);
}
}


public void CloseConnections()
{
// Receive
if(_recvSocket != null)
{
_recvSocket.Shutdown(SocketShutdown.Both);
_recvSocket.Close();
_recvSocket = null;
_recvState.Socket = null;
_recvState = null;
}

// Send
if(_sendSocket != null)
{
_sendSocket.Shutdown(SocketShutdown.Both);
_sendSocket.Close();
_sendSocket = null;
_sendState.Socket = null;
_sendState = null;
}
}