I can't get my overlap event triggered

I have written a function in my .h file

UFUNCTION()
	void TriggerEnter(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool FromSweep, const FHitResult& SweepResult);

and I have attached it to the component

Rock->OnComponentBeginOverlap.AddDynamic(this, &ACollisionActor::TriggerEnter);

All I want is to show a short text

void ACollisionActor::TriggerEnter(class AActor* OtherActor, class UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool FromSweep, const FHitResult& SweepResult)
{
Debug(“TriggerEnter”);
}

but no matter how I hit this object, I just can’t see the text

I think it may be the problem of setting of the object, so I set it like this

99903-360桌面截图20160725112012.jpg

but it is still no working
can anyone offer some help, please