Hi,
i try to understand how to use allocation of Unreal object in Unreal 4.27.2.
if i create a class derived from UObject (UMyClass), and i put some instances of it in a TMap of an actor, it works.
UCLASS()
class DEMO_API UMyClass : public UObject
{
GENERATED_BODY()
public:
UPROPERTY(BlueprintReadOnly, Category = "My_Info")
FString TestString;
UMyClass();
};
UCLASS()
class DEMO_API AMyActor : public AActor
{
GENERATED_BODY()
private:
UPROPERTY(EditAnywhere, Category = MapExample)
TMap<int, UMyClass*> mapTest;
...
}
void AMyActor::BeginPlay()
{
Super::BeginPlay();
mapTest.Add(21, NewObject<UMyClass>() );
}
void AMyActor::Tick(float DeltaTime)
{
Super::Tick(DeltaTime);
if (mapTest.Num() > 0)
{
for (auto& entity : mapTest)
{
FString msg = FString::Printf(TEXT("AMyActor::Tick first: %d"), entity.Key);
GEngine->AddOnScreenDebugMessage(-1, 15.0f, FColor::Red, msg);
}
}
}
But if i put my UMyClass in a class derived from UObject, it crashes 
UCLASS()
class DEMO_API AMyActor : public AActor
{
GENERATED_BODY()
private:
UMyOtherClass* _Test;
...
}
void AMyActor::AMyActor()
{
_Test = CreateDefaultSubobject<UMyOtherClass>("MyTest");
}
void AMyActor::BeginPlay()
{
Super::BeginPlay();
_Test->Init(this);
}
UCLASS()
class DEMO_API UMyOtherClass : public UObject
{
GENERATED_BODY()
public:
UPROPERTY(EditAnywhere, Category = MapExample)
TMap<int, UMyClass*> mapTest;
bool Init();
};
bool UMyOtherClass::Init()
{
mapTest.Add(42, NewObject<UMyClass>()); // It crsh !!!!!
return true;
}
I have tried to use my actor has parent in NewObject and it’s the same thing:
bool UMyOtherClass::Init(AMyActor* parent)
{
mapTest.Add(42, NewObject<UMyClass>(parent)); // It crsh !!!!!
return true;
}
How can i manage instances of a UObject in another UObject ?