C# – downside to adding an anonymous empty delegate on event declaration


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?

Best Solution

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);
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