About the wiki "Delegates in UE4, Raw C++, and BP Exposed"

Development Programming & Scripting C++
1

A question about this wiki:

I try to use the “built in” signature OnComponentBeginOverlap, but can’t manage to bind a function in another class than the class where the overlap is detected. Is this a limitation in the “built in” signatures? I take it it is a way of making some common situations (things overlapping e.g) very easy to handle by letting it trigger a function call without the need to explicitly call Broadcast()?

Binding seems to be done in any class in Rama’s wiki, but I don’t get how I can get the hold of an OBJECT of the class where the delegate signature is defined like RamaMeleeWeaponComp:

“RamaMeleeWeaponComp->RamaMeleeWeapon_OnHit.AddDynamic(this,&USomeClass::RespondToMeleeDamageTaken);”

I have followed a tutorial (https://unrealcpp.com/light-switch-trigger/) and then I go:

LightSphere->OnComponentBeginOverlap.AddDynamic(this, &ALightSwitchTrigger::OnOverlapBegin);

to trigger a function call in the same class, but how to do the same in e.g the main character?

Best regards
Ulf

2

In hindsight, I think what I missed was that an instantiated OBJECT is needed to contain the delegate definition. I thought I could do it so that any spawned actor defining the delegate signature and any other spawned actor with a function to trigger could be bound to each other when spawning (every time they are set loose into the world), but that is probably not possible?

3

Yes, you need an instance of an object to bind any of its functions to a delegate.
Also, keep in mind that the collision delegates are sparse - binding a lot of objects to it is costly.

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