Unity EventManager with delegate instead of UnityEvent

Question

I am looking for c# delegate version of this Manager using UnityEvent. I don\'t want to use this because UnityEvent is slower than C# event at most time.

Any clue on

Answer 1

You can use Action which is actually a delegate declared like this:

namespace System
{
    public delegate void Action();
}

1.Replace all the UnityAction with Action from the System namespace which uses delegates.

2.Replace all thisEvent.AddListener(listener); with thisEvent += listener;

3.Replace all thisEvent.RemoveListener(listener); with thisEvent -= listener;

Here is the modified version of Unity's original EventManager ported to use delegate/Action.

Without Parameter:

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EventManager : MonoBehaviour
{

    private Dictionary eventDictionary;

    private static EventManager eventManager;

    public static EventManager instance
    {
        get
        {
            if (!eventManager)
            {
                eventManager = FindObjectOfType(typeof(EventManager)) as EventManager;

                if (!eventManager)
                {
                    Debug.LogError("There needs to be one active EventManger script on a GameObject in your scene.");
                }
                else
                {
                    eventManager.Init();
                }
            }

            return eventManager;
        }
    }

    void Init()
    {
        if (eventDictionary == null)
        {
            eventDictionary = new Dictionary();
        }
    }

    public static void StartListening(string eventName, Action listener)
    {
        Action thisEvent;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            //Add more event to the existing one
            thisEvent += listener;

            //Update the Dictionary
            instance.eventDictionary[eventName] = thisEvent;
        }
        else
        {
            //Add event to the Dictionary for the first time
            thisEvent += listener;
            instance.eventDictionary.Add(eventName, thisEvent);
        }
    }

    public static void StopListening(string eventName, Action listener)
    {
        if (eventManager == null) return;
        Action thisEvent;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            //Remove event from the existing one
            thisEvent -= listener;

            //Update the Dictionary
            instance.eventDictionary[eventName] = thisEvent;
        }
    }

    public static void TriggerEvent(string eventName)
    {
        Action thisEvent = null;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            thisEvent.Invoke();
            // OR USE instance.eventDictionary[eventName]();
        }
    }
}

Test script:

The test script below test the event by triggering events every 2 seconds.

public class TestScript: MonoBehaviour
{
    private Action someListener;

    void Awake()
    {
        someListener = new Action(SomeFunction);
        StartCoroutine(invokeTest());
    }

    IEnumerator invokeTest()
    {
        WaitForSeconds waitTime = new WaitForSeconds(2);
        while (true)
        {
            yield return waitTime;
            EventManager.TriggerEvent("test");
            yield return waitTime;
            EventManager.TriggerEvent("Spawn");
            yield return waitTime;
            EventManager.TriggerEvent("Destroy");
        }
    }

    void OnEnable()
    {
        EventManager.StartListening("test", someListener);
        EventManager.StartListening("Spawn", SomeOtherFunction);
        EventManager.StartListening("Destroy", SomeThirdFunction);
    }

    void OnDisable()
    {
        EventManager.StopListening("test", someListener);
        EventManager.StopListening("Spawn", SomeOtherFunction);
        EventManager.StopListening("Destroy", SomeThirdFunction);
    }

    void SomeFunction()
    {
        Debug.Log("Some Function was called!");
    }

    void SomeOtherFunction()
    {
        Debug.Log("Some Other Function was called!");
    }

    void SomeThirdFunction()
    {
        Debug.Log("Some Third Function was called!");
    }
}

---

With Parameter:

From other questions, most people are asking how to support parameter. Here it is. You can use class/struct as parameter then add all the variables you want to pass into the function inside this class/struct. I will use EventParam as an example. Feel free to add/remove variables you want to pass in the event EventParam structure at the end of this code.

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class EventManager : MonoBehaviour
{

    private Dictionary> eventDictionary;

    private static EventManager eventManager;

    public static EventManager instance
    {
        get
        {
            if (!eventManager)
            {
                eventManager = FindObjectOfType(typeof(EventManager)) as EventManager;

                if (!eventManager)
                {
                    Debug.LogError("There needs to be one active EventManger script on a GameObject in your scene.");
                }
                else
                {
                    eventManager.Init();
                }
            }
            return eventManager;
        }
    }

    void Init()
    {
        if (eventDictionary == null)
        {
            eventDictionary = new Dictionary>();
        }
    }

    public static void StartListening(string eventName, Action listener)
    {
        Action thisEvent;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            //Add more event to the existing one
            thisEvent += listener;

            //Update the Dictionary
            instance.eventDictionary[eventName] = thisEvent;
        }
        else
        {
            //Add event to the Dictionary for the first time
            thisEvent += listener;
            instance.eventDictionary.Add(eventName, thisEvent);
        }
    }

    public static void StopListening(string eventName, Action listener)
    {
        if (eventManager == null) return;
        Action thisEvent;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            //Remove event from the existing one
            thisEvent -= listener;

            //Update the Dictionary
            instance.eventDictionary[eventName] = thisEvent;
        }
    }

    public static void TriggerEvent(string eventName, EventParam eventParam)
    {
        Action thisEvent = null;
        if (instance.eventDictionary.TryGetValue(eventName, out thisEvent))
        {
            thisEvent.Invoke(eventParam);
            // OR USE  instance.eventDictionary[eventName](eventParam);
        }
    }
}

//Re-usable structure/ Can be a class to. Add all parameters you need inside it
public struct EventParam
{
    public string param1;
    public int param2;
    public float param3;
    public bool param4;
}

Test script:

public class Test : MonoBehaviour
{
    private Action someListener1;
    private Action someListener2;
    private Action someListener3;

    void Awake()
    {
        someListener1 = new Action(SomeFunction);
        someListener2 = new Action(SomeOtherFunction);
        someListener3 = new Action(SomeThirdFunction);

        StartCoroutine(invokeTest());
    }

    IEnumerator invokeTest()
    {
        WaitForSeconds waitTime = new WaitForSeconds(0.5f);

        //Create parameter to pass to the event
        EventParam eventParam = new EventParam();
        eventParam.param1 = "Hello";
        eventParam.param2 = 99;
        eventParam.param3 = 43.4f;
        eventParam.param4 = true;

        while (true)
        {
            yield return waitTime;
            EventManager.TriggerEvent("test", eventParam);
            yield return waitTime;
            EventManager.TriggerEvent("Spawn", eventParam);
            yield return waitTime;
            EventManager.TriggerEvent("Destroy", eventParam);
        }
    }

    void OnEnable()
    {
        //Register With Action variable
        EventManager.StartListening("test", someListener1);
        EventManager.StartListening("Spawn", someListener2);
        EventManager.StartListening("Destroy", someListener3);

        //OR Register Directly to function
        EventManager.StartListening("test", SomeFunction);
        EventManager.StartListening("Spawn", SomeOtherFunction);
        EventManager.StartListening("Destroy", SomeThirdFunction);
    }

    void OnDisable()
    {
        //Un-Register With Action variable
        EventManager.StopListening("test", someListener1);
        EventManager.StopListening("Spawn", someListener2);
        EventManager.StopListening("Destroy", someListener3);

        //OR Un-Register Directly to function
        EventManager.StopListening("test", SomeFunction);
        EventManager.StopListening("Spawn", SomeOtherFunction);
        EventManager.StopListening("Destroy", SomeThirdFunction);
    }

    void SomeFunction(EventParam eventParam)
    {
        Debug.Log("Some Function was called!");
    }

    void SomeOtherFunction(EventParam eventParam)
    {
        Debug.Log("Some Other Function was called!");
    }

    void SomeThirdFunction(EventParam eventParam)
    {
        Debug.Log("Some Third Function was called!");
    }
}