如何在UE5中使用输入映射上下文（无蓝图）

Question

我是UE5初学者（昨天开始学习），现在正在做一个简单的任务。 它需要 WSAD 和鼠标使用输入映射上下文进行简单的移动和相机操作。

然而，在我自学之后，我最终得到了这个：

UCLASS()
class ASSIGNMENT1_API AFirstPersonCharactor : public ACharacter
{
    GENERATED_BODY()

public:
    // Sets default values for this character's properties
    AFirstPersonCharactor();
    UPROPERTY(EditAnywhere, Category = "Components|Camera")
    UCameraComponent* camera;


    UPROPERTY(EditAnywhere, Category = "Input|Actions")
    UInputAction *IA_KB_CM_InOut;
    UPROPERTY(EditAnywhere, Category = "Input|Actions")
    UInputAction* IA_KB_CM_LeftRight;
    UPROPERTY(EditAnywhere, Category = "Input|Actions")
    UInputAction* IA_KB_CL_UpDown;
    UPROPERTY(EditAnywhere, Category = "Input|Actions")
    UInputAction* IA_KB_CL_LeftRight;



    UPROPERTY(EditAnywhere, Category = "Input|Actions")
    TSoftObjectPtr<UInputMappingContext> IMCControls;

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

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

    // Called to bind functionality to input
    virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;

    void KB_CM_InOut(const FInputActionInstance& Instance);

    void KB_CM_LeftRight(const FInputActionInstance& Instance);

    void KB_CL_UpDown(const FInputActionInstance& Instance);

    void KB_CL_LeftRight(const FInputActionInstance& Instance);

};

这是我的 cpp 文件：

// Sets default values
AFirstPersonCharactor::AFirstPersonCharactor()
{
    PrimaryActorTick.bCanEverTick = true;

    camera = CreateDefaultSubobject<UCameraComponent>(TEXT("FirstPersonCamera"));
    camera->SetupAttachment(RootComponent);
    camera->SetRelativeLocation(FVector(0));

}

void AFirstPersonCharactor::BeginPlay()
{
    Super::BeginPlay();
}

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

}

// Called to bind functionality to input
void AFirstPersonCharactor::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
    Super::SetupPlayerInputComponent(PlayerInputComponent);
    if (ULocalPlayer* LocalPlayer = Cast<ULocalPlayer>(GetController()))
    {   
        
        if (UEnhancedInputLocalPlayerSubsystem* InputSystem = LocalPlayer->GetSubsystem<UEnhancedInputLocalPlayerSubsystem>())
        {
            InputSystem->AddMappingContext(IMCControls.LoadSynchronous(),10);
        }
    }
    
    UEnhancedInputComponent* input = Cast<UEnhancedInputComponent>(PlayerInputComponent);

    if (IA_KB_CM_InOut) {
        input->BindAction(IA_KB_CM_InOut, ETriggerEvent::Started, this, &AFirstPersonCharactor::KB_CM_InOut);
    }
    if (IA_KB_CM_LeftRight) {
        input->BindAction(IA_KB_CM_LeftRight, ETriggerEvent::Started, this, &AFirstPersonCharactor::KB_CM_LeftRight);
    }
    if (IA_KB_CL_UpDown) {
        input->BindAction(IA_KB_CL_UpDown, ETriggerEvent::Started, this, &AFirstPersonCharactor::KB_CL_UpDown);
    }
    if (IA_KB_CL_LeftRight) {
        input->BindAction(IA_KB_CL_LeftRight, ETriggerEvent::Started, this, &AFirstPersonCharactor::KB_CL_LeftRight);
    }
}

void AFirstPersonCharactor::KB_CM_InOut(const FInputActionInstance &Instance)
{
    printf("a");
    float FloatValue = Instance.GetValue().Get<float>();
    if (FloatValue != 0) {
        AddMovementInput(GetActorForwardVector(),FloatValue);
    }
}

void AFirstPersonCharactor::KB_CM_LeftRight(const FInputActionInstance& Instance)
{
    float FloatValue = Instance.GetValue().Get<float>();
    if (FloatValue != 0) {
        AddMovementInput(GetActorRightVector(), FloatValue);
    }

}

void AFirstPersonCharactor::KB_CL_LeftRight(const FInputActionInstance& Instance)
{
    float FloatValue = Instance.GetValue().Get<float>();
    if (FloatValue != 0) {
        AddControllerYawInput(FloatValue);
    }
}

void AFirstPersonCharactor::KB_CL_UpDown(const FInputActionInstance& Instance)
{
    float FloatValue = Instance.GetValue().Get<float>();
    if (FloatValue != 0) {
        AddControllerPitchInput(FloatValue);
    }
}

这以没有错误结束，并且我在大纲中设置了inputAction和inputMappingContext资产。 但是无论我按哪个键，总是没有我可以观察到的行为。

编辑：在我添加GEngine->AddOnScreenDebugMessage(-1, 5.f, FColor::Red, TEXT("haha")); 为了调试，我发现我的SetupPlayerInputComponent正在工作，但是

if (ULocalPlayer* LocalPlayer = Cast<ULocalPlayer>(GetController()))

可能不会。

Answer 1

您不应该尝试将 controller 投射到本地播放器，而且您宁愿在BeginPlay()而不是SetupInputComponent(...)中设置MappingContext 。 因此，与其执行该转换然后尝试添加映射上下文，不如这样做：

if (auto PlayerController = Cast<APlayerController>(Controller))
{
    if (UEnhancedInputLocalPlayerSubsystem* Subsystem = ULocalPlayer::GetSubsystem<UEnhancedInputLocalPlayerSubsystem>(PlayerController->GetLocalPlayer()))
    {
        Subsystem->AddMappingContext(DefaultMappingContext, 0);
    }
}