Event System with callbacks

I am implementing an event system in my game, but I am not too sure how to also implement a callbacks into the system. Now I just have a delegate and two events for it, one is the a normal event and the other one is a callback. Here's an example:

Code (CSharp):

1. public delegate void LoadGame(int sceneID);
2.     public event LoadGame LoadGameAction;
3.     public event LoadGame LoadGameCallback;

I don't feel like this is an efficient and good way to make callbacks.

 

What do you mean "one is the a normal event and the other one is a callback"? What do you see is the difference here?

I actually don't bother with making a delegate definition. In fact, I avoid it because whenever I see an event that uses "SomeDelegate" definition, I have to go and look it up to know what parameters I'm expected to pass in. So I just do stuff like this:

Code (csharp):

1.  
2. public event Action<int> OnValueChanged;
3. public event Action OnUpdated;
4.  

and so on...

 

What I mean is that, when I want to load a game, I want my loading method to send a callback when the game data has been loaded, so other scripts know that the game can continue or start.

 

This is an event:

public event LoadGame LoadGameAction;

.

This is a callback:

public void LoadLevel(int level, Action<int> OnLevelLoaded) {...}

With events, you can have multiple listeners. With callbacks, well, there's usually only one listener -- the caller. Sure, you could rework it so you can support multiple listeners for callbacks... but in that case you might as well use events instead.

It's up to you to decide which approach makes the most sense. Personally I'd use events. They help keep the UI and game logic from getting tied together into a spaghetti mess of code.