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UE4 反射学习笔记

news 来源：原创 2024/11/13 13:34:50

想让类具有反射机制，必须要有这四个要素：

1、generated.h文件

2、UCLASS()宏

3、继承自UObject

4、GENERATED_BODY()

void ABlurCharacter::BeginPlay()
{
	Super::BeginPlay();

	ABlurCharacter *BlurCharacter = NewObject<ABlurCharacter>();
	UClass *BlurCharacterClass = BlurCharacter->GetClass();
	FName BlurCharacterName = BlurCharacterClass->GetFName();

	GEngine->AddOnScreenDebugMessage(-1, 10.f ,FColor::Red, *BlurCharacterName.ToString());
}

这样就将类名给输出出来了

for(UProperty *Per = BlurCharacterClass->PropertyLink; Per; Per = Per->PropertyLinkNext)
	{
		if(Per->GetCPPType() == TEXT("FString"))
		{
			UStrProperty *Str = Cast<UStrProperty>(Per);
			void *Addr = Str->ContainerPtrToValuePtr<void>(BlurCharacter);  //从容器信息转变成具体值
			GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Yellow, Per->GetName() + TEXT(" ------ ") + Per->GetCPPType() +
				TEXT(" ------ ") + Str->GetPropertyValue(Addr));
            Str->SetPropertyValue(Addr, "AfterModified");
			GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Yellow, Per->GetName() + TEXT(" ------ ") + Per->GetCPPType() +
				TEXT(" ------ ") + Str->GetPropertyValue(Addr));
		}
	}

UPROPERTY()
	FString Hello = "Hello World";

获取类中FString类型的值、类型、和名称，根据代码可以看出，存储变量的数据结构是一个链表，注意，变量一定要用UPROPERTY()给包裹，不然不会将变量信息反射到链表，更不可能存取这些信息

for(TFieldIterator<UFunction> Iter(BlurCharacterClass); Iter; ++Iter)
	{
		GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Blue, Iter->GetName());
		for(TFieldIterator<UProperty> Iter1(*Iter); Iter1; ++Iter1)
		{
			GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Black, Iter1->GetName() + TEXT(" ------ ") + Iter1->GetCPPType());
		}
	}

同理，自己写的函数也必须加入UFUNCTION()

void ABeginInvokeGameModeBase::BeginPlay() {
	Super::BeginPlay();

	AAFloorSwitch* FloorSwitch = NewObject<AAFloorSwitch>();

	UClass* Father = FloorSwitch->GetClass()->GetSuperClass();
	FString Name = Father->GetName();
	GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Red, Name);
}

UCLASS()
class MYCTEST_API AAFloorSwitch : public AActor
{
	GENERATED_BODY()
	
public:	
	// Sets default values for this actor's properties
	AAFloorSwitch();
}