UActorComponent::OnComponentActivated

property Engine Blueprint Since 4.14

#include "Components/ActorComponent.h"

Access: public Specifiers: UPROPERTYBlueprintAssignable

Description

Dynamic multicast delegate fired whenever the component is activated. Broadcasts the activated component and whether it was a reset activation.

Caveats & Gotchas

• Declared as a sparse delegate (DECLARE_DYNAMIC_MULTICAST_SPARSE_DELEGATE_TwoParams), meaning it doesn't allocate memory until at least one binding exists — be aware that binding from C++ requires using the broadcast functions correctly.
• Fires after the bIsActive flag is set to true, so IsActive() returns true inside delegate callbacks.
• Not fired during component construction or BeginPlay's auto-activation unless Activate() is explicitly called. Components with bAutoActivate=true call Activate() during RegisterComponent, which does fire this delegate.

Signature

UPROPERTY(BlueprintAssignable, Category = "Components|Activation")
FActorComponentActivatedSignature OnComponentActivated;

Example

Bind in C++ C++

MyComponent->OnComponentActivated.AddDynamic(this, &AMyActor::HandleComponentActivated);

void AMyActor::HandleComponentActivated(UActorComponent* Component, bool bReset)
{
    UE_LOG(LogTemp, Log, TEXT("%s activated, reset=%d"), *Component->GetName(), bReset);
}

Version History

Introduced in: 4.14

Version	Status	Notes
5.6	stable	—

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