UEC 利用代理/委托写一个生命组件

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首先基于ActorComponent创建一个组件 HealthComponent，将需要的变量与函数创建

#include "CoreMinimal.h"

#include "Components/ActorComponent.h"

#include "HealthComponent.generated.h"

UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )

class PVETPC_API UHealthComponent : public UActorComponent

{

    GENERATED_BODY()

public:

    // Sets default values for this component's properties

    UHealthComponent();

    // 初始化健康值

    UFUNCTION(BlueprintCallable)

        void Init(int taotalHealth,int currentHealth);

    // 造成伤害

    UFUNCTION(BlueprintCallable)

        void HanldTakeAnyDamaged(AActor* DamagedActor, float Damage, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser);

    // 恢复健康值

    UFUNCTION(BlueprintCallable)

        void RestoreHealth(int restoreValue);

    UFUNCTION(BlueprintPure)

        float GetHealth() { return CurrentHealth; }

protected:

    // 总健康值

    float TotalHealth;

    // 当前健康值

    float CurrentHealth;

    // Called when the game starts

    virtual void BeginPlay() override;

public:

    // Called every frame

    virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;

};

这里的 HanldTakeAnyDamaged 函数是通过代理绑定到拥有者身上

HanldTakeAnyDamaged 需要的形参需要与 OnTakeAnyDamage 的宏定义一致

除此之外还有 OnTakePointDamage 和 OnTakeRadialDamage 也是一样的操作

#include "Components/HealthComponent.h"

#include "Engine.h"

#include "Kismet/KismetSystemLibrary.h"

// Sets default values for this component's properties

UHealthComponent::UHealthComponent()

{

    // Set this component to be initialized when the game starts, and to be ticked every frame.  You can turn these features

    // off to improve performance if you don't need them.

    PrimaryComponentTick.bCanEverTick = true;

    // ...

}

void UHealthComponent::Init(int taotalHealth, int currentHealth)

{

    TotalHealth = taotalHealth;

    CurrentHealth = currentHealth;

}

void UHealthComponent::HanldTakeAnyDamaged(AActor* DamagedActor, float Damage, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser)

{

    if (Damage <= 0) { return; }

    CurrentHealth = FMath::Clamp( CurrentHealth - Damage , 0.f, TotalHealth);

    UE_LOG(LogTemp, Warning, TEXT("I am Demaged! CurrentHealth = %f"), CurrentHealth);

}

void UHealthComponent::RestoreHealth(int restoreValue)

{

    CurrentHealth = FMath::Clamp(CurrentHealth + restoreValue, 0.f, TotalHealth);

    GEngine->AddOnScreenDebugMessage(-1, 20, FColor::Red, FString(TEXT("I am RestoreHealth!")));

}

// Called when the game starts

void UHealthComponent::BeginPlay()

{

    Super::BeginPlay();

    // 获取拥有者

    AActor* MyOwner = GetOwner();

    // 如果存在就将伤害接收函数绑定

    if (MyOwner)

    {

        UE_LOG(LogTemp, Warning, TEXT("I am bound!"));

        MyOwner->OnTakeAnyDamage.AddDynamic(this, &UHealthComponent::HanldTakeAnyDamaged);

    }

    Init(100,100);

    // ...

}

// Called every frame

void UHealthComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)

{

    Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

    // ...

}

这时候我们将该组件挂载在角色身上，已经有了效果，但是角色不知道组件生命值是否改变

接着我们在组件头文件的头文件申明下添加代理的宏定义，并创建一个代理对象

并在需要响应的函数中添加广播

#include "CoreMinimal.h"

#include "Components/ActorComponent.h"

#include "HealthComponent.generated.h"

// 自定义六参数代理事件

DECLARE_DYNAMIC_MULTICAST_DELEGATE_SixParams(FOnHealthChangedSignature, UHealthComponent*, HealthComp, float, Health, float, HealthDelta, const class UDamageType*, DamageType, class AController*, InstigatedBy, AActor*, DamageCauser);

......

    // 恢复健康值

    UFUNCTION(BlueprintCallable)

        void RestoreHealth(int restoreValue);

    UFUNCTION(BlueprintPure)

        float GetHealth() { return CurrentHealth; }

       // 定义代理

    UPROPERTY(BlueprintAssignable, Category = "Events")

        FOnHealthChangedSignature OnHealthChanged;

......

void UHealthComponent::HanldTakeAnyDamaged(AActor* DamagedActor, float Damage, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser)

{

    if (Damage <= 0) { return; }

    CurrentHealth = FMath::Clamp( CurrentHealth - Damage , 0.f, TotalHealth);

    UE_LOG(LogTemp, Warning, TEXT("I am Demaged! CurrentHealth = %f"), CurrentHealth);

    // 每当该函数被调用时，就将调用一次代理函数

    OnHealthChanged.Broadcast(this, CurrentHealth, Damage, DamageType, InstigatedBy, DamageCauser);

}

最后再到拥有者类中添加一个用于回调的操作函数，其中形参对应在生命组件中定义的那样（注意命名是否重复）

头文件

    // 代理事件

    UFUNCTION()

    void OnHealthChanged(UHealthComponent* OnwerHealthComp, float Health, float HealthDelta,

        const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser);

cpp文件

void APCharacter::OnHealthChanged(UHealthComponent* OnwerHealthComp, float Health, float HealthDelta, const class UDamageType* DamageType, class AController* InstigatedBy, AActor* DamageCauser)

{

    if (IsDeath) return;

    UE_LOG(LogTemp, Warning, TEXT("I know I was hurt! "));

    if (Health <= 0 && !IsDeath)

    {

        UE_LOG(LogTemp, Warning, TEXT("I am Death! "));

        IsDeath = true;
　　　　　Death();

        GetMovementComponent()->StopMovementImmediately();

        GetCapsuleComponent()->SetCollisionEnabled(ECollisionEnabled::NoCollision);

        // 分离控制器

        DetachFromControllerPendingDestroy();

        // 3秒后执行

        SetLifeSpan(3.0f);
    }

}

void APCharacter::BeginPlay()

{

    Super::BeginPlay();

    HealthComp->OnHealthChanged.AddDynamic(this, &APCharacter::OnHealthChanged);

}