C++中调用蓝图函数

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// 在头文件中声明函数
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UCLASS()
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class MYGAME_API AMyActor : public AActor
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{
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    GENERATED_BODY()
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public:
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    // 纯蓝图实现事件 - 没有C++定义
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    UFUNCTION(BlueprintImplementableEvent, Category="MyGame")
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    void OnBlueprintEvent(int32 Value, const FString& Message);
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    // 带默认C++实现的蓝图事件
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    UFUNCTION(BlueprintNativeEvent, Category="MyGame")
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    float CalculateValue(float BaseValue);
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    // 调用函数示例
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    void CallBlueprintFunctions();
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};

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// 定义接口
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UINTERFACE(BlueprintType)
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class MYGAME_API UMyInterface : public UInterface
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{
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    GENERATED_BODY()
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};
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class MYGAME_API IMyInterface
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{
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    GENERATED_BODY()
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public:
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    UFUNCTION(BlueprintCallable, BlueprintImplementableEvent)
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    void OnInteract(AActor* Instigator);
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    UFUNCTION(BlueprintCallable, BlueprintNativeEvent)
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    bool CanInteract() const;
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};
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// 实现接口的默认C++方法
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bool IMyInterface::CanInteract_Implementation() const
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{
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    return true;
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}
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// 在C++中调用接口方法
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void AMyActor::InteractWithObject(AActor* TargetActor)
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{
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    if (TargetActor->GetClass()->ImplementsInterface(UMyInterface::StaticClass()))
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    {
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        // 检查是否可以交互
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        if (IMyInterface::Execute_CanInteract(TargetActor))
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        {
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            // 调用蓝图实现的方法
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            IMyInterface::Execute_OnInteract(TargetActor, this);
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        }
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    }
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}

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UCLASS()
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class MYGAME_API AMyActor : public AActor
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{
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    GENERATED_BODY()
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public:
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    // 声明动态多播委托
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    UPROPERTY(BlueprintAssignable, Category="Events")
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    FOnCustomEventSignature OnCustomEvent;
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    // 声明动态委托
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    UPROPERTY(BlueprintAssignable, Category="Events")
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    FOnCalculateValueSignature OnCalculateValue;
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    // 触发事件
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    void TriggerEvents();
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};
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// 在CPP中实现
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void AMyActor::TriggerEvents()
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{
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    // 广播多播委托
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    OnCustomEvent.Broadcast(42, TEXT("Event triggered"));
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    // 执行委托并获取结果
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    if (OnCalculateValue.IsBound())
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    {
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        float Result = OnCalculateValue.Execute(100.0f);
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    }
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}

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// 获取蓝图类实例
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AActor* BlueprintActor = /* 获取BP实例的引用 */;
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// 方法1: 使用ProcessEvent直接调用
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FName FunctionName = "BlueprintFunction";
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BlueprintActor->ProcessEvent(BlueprintActor->FindFunction(FunctionName), &Params);
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// 方法2: 使用ExecuteUbergraph (仅限事件图表入口点)
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BlueprintActor->ExecuteUbergraph(/* 图表入口点索引 */);
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// 方法3: 推荐方式 - 使用InvokeFunction模板函数
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FOutputParams Result;
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UFunction* Function = BlueprintActor->FindFunction(TEXT("MyBlueprintFunction"));
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if (Function)
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{
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    struct
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    {
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        float InParam1;
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        FString InParam2;
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        int32 ReturnValue;
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    } Params;
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    Params.InParam1 = 10.0f;
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    Params.InParam2 = TEXT("Hello");
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    BlueprintActor->ProcessEvent(Function, &Params);
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    int32 ReturnValue = Params.ReturnValue;
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}