Raising events in C# that ignore exceptions raised by handlers

Question

One of my pet peeves with raising events in C# is the fact that an exception in an event handler will break my code, and possibly prevent other handlers from being called, if the broken one happened to get called first; In most cases my code couldn't care less if somebody else's code that's listening to its events is broken.

I created an extension method that catches exceptions:

public static void Raise(this EventHandler eh, object sender, EventArgs e)
{
  if (eh == null)
    return;
  try
  {
    eh(sender, e);
  }
  catch { }
}

Although this does mean my code carries on regardless, this method doesn't stop a first event handler throwing an exception and preventing second and subsequent handlers being notified of the event. I'm looking into a way of iterating through GetInvocationList to wrap each individual event handler in it's own try/catch, but this seems inefficient, and I'm not certain of the best way to do it, or even if I should be.

Also, I'm really not comfortable simply ignoring the exception here (and neither's FxCop/Resharper for that matter); realistically what should happen to the exception in this case?

Answer 1

What if you did something like this?

public static void Raise(this EventHandler eh, object sender, EventArgs e)
{
    if (eh == null)
        return;

    foreach(var handler in eh.GetInvocationList().Cast<EventHandler>())
    {
        try
        {
            handler(sender, e);
        }
        catch { }
    }
}

Answer 2

You should only trap those exceptions you can handle. For example you might be accessing a file and not have sufficient privileges. If you know this can happen occasionally and all that needs to happen is that the case is logged then trap that exception alone.

If your code can't handle the exception then don't trap it.

It's an exceptional circumstance so there's a good chance the other event handlers won't be able to "do their stuff" either, so let it propagate to a level where it can be handled safely.