[Quickfix-developers] Custom Messages and .Net Invoke

[Andrew R. \(TT\) <and...@tr...>]

I have developed a FIX GUI app which is an initiator.  Thus, every time
I receive an update, I pass it to the GUI as:

 

public delegate void MessageListener(QuickFix.Message message);

public MessageListener messageListeners;

 

public void registerMessageListener(MessageListener ml)

{

  messageListeners += ml;

}

 

public virtual void fromApp(QuickFix.Message message, QuickFix.SessionID
sessionID)

{

  if (_control != null && _control.InvokeRequired)

  {

    _control.Invoke(new MessageListener(messageListeners), new Object[]
{ message });

  }

}

 

This has always worked great.  Recently, the server to which I connect
added a custom message that I needed to process.  So I derived a new
custom message.  Specifically, I simply copied another 4.2 message from
the C# QuickFIX source and modified it.  I also created a custom message
factory and added this new message to my data dictionary.

 

Whenever I receive an update for a standard FIX message, everything
still works fine.  Whenever I receive an update for this new custom
message, I get an invalid cast exception that points to my
"_control.Invoke" line.

 

System.InvalidCastException was unhandled

  Message="At least one element in the source array could not be cast
down to the destination array type."

  Source="System.Windows.Forms"

  StackTrace:

       at System.Windows.Forms.Control.MarshaledInvoke(Control caller,
Delegate method, Object[] args, Boolean synchronous)

       at System.Windows.Forms.Control.Invoke(Delegate method, Object[]
args)

       at QuickFix.TTQuickFix.fromApp(Message message, SessionID
sessionID) in C:\Documents and Settings\me\My Documents\Visual Studio
2005\Projects\MyApp\MyApp\MyApp.cs:line 168

       at Application.fromApp(Application* , Message* message,
SessionID* sessionID)

 

 

Why is this an invalid cast?  What did I forget?  Any help would be
appreciated.