Is there a downside to adding an anonymous empty delegate on event declaration?

Question

I have seen a few mentions of this idiom (including on SO):

// Deliberately empty subscriber public event EventHandler AskQuestion = delegate {}; 

The upside is clear - it avoids the need to check for null before raising the event.

However, I am keen to understand if there are any downsides. For example, is it something that is in widespread use and is transparent enough that it won't cause a maintenance headache? Is there any appreciable performance hit of the empty event subscriber call?

Answer 1

Instead of inducing performance overhead, why not use an extension method to alleviate both problems:

public static void Raise(this EventHandler handler, object sender, EventArgs e) {     if(handler != null)     {         handler(sender, e);     } } 

Once defined, you never have to do another null event check again:

// Works, even for null events. MyButtonClick.Raise(this, EventArgs.Empty);