Event Bus in basic c# events

Question

I try to write event bus. I have

public class EventBusArgs<T> : EventArgs
    {
        private T _value;
        public EventBusArgs(T @value)
        {
            _value = @value;
        }
        public T Value
        {
            get
            {
                return _value;
            }
        }
    }

public enum EventType
    {
        None,
        PrintInt1,
        PrintString1,

    }

public class EventManager : GlobalSingleton<EventManager>
    {
        private static Dictionary<EventType, EventHandler<EventArgs>> _eventBus;

        public override void Awake()
        {
            base.Awake();
            if (_eventBus == null)
            {
                _eventBus = new Dictionary<EventType, EventHandler<EventArgs>>();
            }
        }

        public static void StartListening(EventType eventType, EventHandler<EventArgs> eventHandler)
        {
            if (_eventBus.ContainsKey(eventType))
            {
                _eventBus[eventType] += eventHandler;
            }
            else
            {
                _eventBus.Add(eventType, eventHandler);
            }
        } 

        public void Start()
        {
            StartListening(EventType.PrintInt1, PrintInt1);// error here
        }

        private void PrintInt1(object sender, EventBusArgs<int> number)// because it is not (object sender, EventArgs number)
        {
            Debug.Log($"the number in PrintInt1 is {number.Value}");
        }
    }

But I have error: cannot convert from "method group" to EventHandler . When I use EventArgs instead of EventBusArgs programs works without error.

How I can fix it and use EventBusArgs? Because I want use double, Vector3 and my custom classes...

Answer 1

Just cast the EventArgs to your EventBusArgs in the Callbacks (in this case PrintInt1).

private void PrintInt1(object sender, EventArgs eventArgs)
{
    EventBusArgs<int> number = (EventBusArgs<int>)eventArgs;
    Debug.Log($"the number in PrintInt1 is {number.Value}");
}

Changes can be found here: https://dotnetfiddle.net/NLsHms