使用 UnityActions 或 C# Actions 时如何最好地避免内存泄漏

Question

Ok, I am working with public static UnityActions for event driven multi delegate execution and I want to avoid memory leaks. I am worried that I miss removing a registered delegate. So I came up with the following construct: Immediately when registering for an event I also register the command for unregistering to a separate action that I can execute at the end of the program like so:

// first establish a delegate to collect everything we need to de-register later OnDestroy
private delegate void Dreg();
private Dreg dreg;

// register for the event and create an entry in the de-register list 
//for later execution:
            MyEvents.SomeEvent += HandleSomeEvent;
            dreg += () => { MyEvents.SomeEvent -= HandleSomeEvent; };

At the end of the application I just need to invoke "dreg" to clear all registrations. This si working fine so far.

My question is: Can I wrap these two statements more elegantly into a function so that I just have to issue one statement instead of two? I have tried but I fail in the assignments. My experiment looked something like this:

public static void RegisterForEvent(UnityAction _eventToRegisterFor, UnityAction _thingToAdd)
{
    _eventToRegisterFor += _thingToAdd;
    dreg += () => _eventToRegisterFor -= _delegateToAdd;
}
...
...Register(MyEvents.SomeEvent,HandleSomeEvent);// using this to register

...
...dreg.invoke;//near the end of the application to de-register everything

This does not seem to be possible. My problem seems to be that I don't quite understand, what type "thingToAdd" actually is that I am assigning to MyEvents.SomeEvent? Is that a delegate? Is it a string that is resolved at runtime? is it a function?? I tried to work with C# Actions as well but did not succeed with that either. Any suggestions will be much appreciated: Many thx before hand :-)

Answer 1

Here is the way I solved this:

//---------------------------------------------------------------------------------------------    
public static void RegisterForEvent(UnityAction _eventToRegisterFor, UnityAction _handlerToAdd)
{
    _eventToRegisterFor += _handlerToAdd;
    dreg += () => _eventToRegisterFor -= _handlerToAdd;
}

//---------------------------------------------------------------------------------------------
//...the two lines above could be replaced with this one line call...

RegisterForEvent(MyEvents.SomeEvent,HandlerForSomeEvent);

//---------------------------------------------------------------------------------------------
//...and at the end the invokation of "dreg" will clear the event delegates
private void OnDestroy()
{
    dreg.invoke;//near the end of the application to de-register everything
}