C# Events without arguments. How do I handle them?

Question

I\'m currently working on a menu system for a game and I have the standard hierarchy for screens and screen elements. (Screens contain some collection of screen elements). I

Answer 1

You can use Action delegates. This is much more elegantly then using data you will never need (I mean EventArgs).

Here you define events:

public event Action EventWithoutParams;
public event Action<int> EventWithIntParam;

And here you fire events:

EventWithoutParams();
EventWithIntParam(123);

You can find all the information you need at Action or Action<T>.

Either of these events can be initialised with a no-op delegate ... = delegate { }; so that you don't need to check for null before firing the event.

Answer 2

You can just write:

public event EventHandler Selected;

Answer 3

Try:

public event EventHandler Selected;

then to call..

Selected(null, EventArgs.Empty);

This way it's the default event definition and you don't need to pass any information if you don't want to.

Answer 4

(Maybe just the EventArgs base class?)

You should do exactly that.

From the MSDN Docs on EventArgs:

This class contains no event data; it is used by events that do not pass state information to an event handler when an event is raised.

Answer 5

Going by the PlayerIndexEventArgs type you mentioned, I am assuming you are using XNA, right? If so, take a look at the Game State Management sample. If not the code might help you understand how to do it anyway.