C++ Battery Collector 教程的编译错误

Question

抱歉，收到了一个非常菜鸟的问题，我一直在处理来自 Unreal 的 C++ Battery Collector tutorial，但我在教程中的代码中遇到了一些编译问题。

我一直在 Visual Studio 中跟进，在头文件中创建访问器方法时，我使用 Intelli 感知来生成对应的类。

Pickup.h

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "Pickup.generated.h"

UCLASS()
class BATTERYCOLLECTOR_API APickup : public AActor
{
    GENERATED_BODY()

public: 
    // Sets default values for this actor's properties
    APickup();

    // Called every frame
    virtual void Tick(float DeltaTime) override;

    // Return the mesh for the pickup
    FORCEINLINE class UStaticMeshComponent* GetMesh() const { return PickupMesh; }

    // Return whether or not the pickup is active
    UFUNCTION(BlueprintPure, Category = "Pickup");  // <--- error in this line
    bool IsActive();

    // Allows other classes to safely change whether or not the pickup is active 
    UFUNCTION(BlueprintCallable, Category = "Pickup");
    void setActive(bool NewPickupState);

protected:
    // Called when the game starts or when spawned
    virtual void BeginPlay() override;

    //True when the pickup can be used, and false when pickup is deactivated
    bool bIsActive;

private:
    //Static mesh to represent the pickup in the level
    UPROPERTY(visibleAnywhere, BlueprintReadOnly, Category = "Pickup", meta = (AllowPrivateAccess = "true"))
    class UStaticMeshComponent* PickupMesh;

};

Pickup.cpp

#include "Pickup.h"

// Sets default values
APickup::APickup()
{
    // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
    PrimaryActorTick.bCanEverTick = false;

    // All pickups start active
    bIsActive = true;

    // Create the static mesh component
    PickupMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("PickupMesh"));

}

// Called when the game starts or when spawned
void APickup::BeginPlay()
{
    Super::BeginPlay();

}

// Called every frame
void APickup::Tick(float DeltaTime)
{
    Super::Tick(DeltaTime);

}

// Visual studio created this definition 
//APickup::UFUNCTION(BlueprintPure, Category)
//{
    //What is should go in here?
//}

// Returns active state
bool APickup::IsActive()
{
    return bIsActive;
}

// Changes active state
void APickup::setActive(bool NewPickupState)
{
    bIsActive = NewPickupState;
}

在我在 .cpp 文件中添加注释 Visual studio created this definition 的那一行，这是由 Visual Studio 代码添加的定义，但我不确定它应该用于什么，没有它就无法编译。 （教程中没有这个定义，但是 VS 要我添加它。）

据我所知，我已经为这两个 UFUNCTIONS 定义了方法，但是如果我没有生成的定义，我会在虚幻引擎中得到编译错误。

D:/Unreal Projects/BatteryCollector/Source/BatteryCollector/Pickup.h(25) : Error: Function return type: Missing variable type

谁能看到我做错了什么或遗漏了什么？

Answer 1

来自Unreal documentation：

UFUNCTION([specifier, specifier, ...], [meta(key=value, key=value, ...)])
ReturnType FunctionName([Parameter, Parameter, ...])

该声明中没有;，很可能这就是问题所在。

请注意，在编辑问题的过程中，您还在另一个声明中添加了 ;，但您应该删除两者。

PS：我将此作为答案发布，希望将半垃圾邮件的 cmets 变成有用的东西。我不知道虚幻，也许这个答案是错误的，那就告诉我吧。