Question

I have an Unhandled Exception handler that does something like this:

  AddHandler Application.ThreadException, AddressOf Application_ThreadException

I was looking at what exactly this means and noticed that the decompiled code for Application shows:

        /// <include file='doc\Application.uex' path='docs/doc[@for="Application.ThreadException"]/*' />
        /// <devdoc> 
        ///    <para>Occurs when an untrapped thread exception is thrown.</para>
        /// </devdoc>
        public static event ThreadExceptionEventHandler ThreadException {
            add { 
                Debug.WriteLineIf(IntSecurity.SecurityDemand.TraceVerbose, "AffectThreadBehavior Demanded");
                IntSecurity.AffectThreadBehavior.Demand(); 

                ThreadContext current = ThreadContext.FromCurrent();
                lock(current) { 
                    current.threadExceptionHandler = value;
                }
            }
            remove { 
                ThreadContext current = ThreadContext.FromCurrent();
                lock(current) { 
                    current.threadExceptionHandler -= value; 
                }
            } 
        }

So it looks like from the “add” that the last person that subscribes to Application.ThreadException is the one who gets it (it’s not additive as most event handlers are). I don’t want to give up my subscription to this eventhandler no matter what. Can anyone think of a way that I could track when I lose my subscription to the Application.ThreadException so I can steal it back from whoever stole it from me?

Answer 1

I am thinking maybe I can do this with a Timer. Check if someone is already subscribed to this event and it is not me then re-subscribe. I know this is a little hackey… just thinking…