简书链接:unrealenginec不修改蓝图的情况下调用蓝图多种方式研究
文章字数：159,阅读全文大约需要1分钟

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/方法原型
int32 UMyClass::Func(float param1); 

UFUNCTION(BlueprintCallable)
int32 InvokeFunction(UObject* obj, FName functionName,float param1)
{
    struct MyClass_Func_Parms   //定义一个结构用来包装参数和返回值，就像在gen.cpp里那样
    {
        float param1;
        int32 ReturnValue;
    };
    UFunction* func = obj->FindFunctionChecked(functionName);
    MyClass_Func_Parms params;
    params.param1=param1;
    obj->ProcessEvent(func, &params);
    return params.ReturnValue;
}
//使用
int r=InvokeFunction(obj,"Func",123.f);

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/调用1
obj->ProcessEvent(func, &params);
//调用2
FFrame frame(nullptr, func, &params, nullptr, func->Children);
obj->CallFunction(frame, &params + func->ReturnValueOffset, func);
//调用3
FFrame frame(nullptr, func, &params, nullptr, func->Children);
func->Invoke(obj, frame, &params + func->ReturnValueOffset);

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template<typename... TReturns, typename... TArgs>
void InvokeFunction(UClass* objClass, UObject* obj, UFunction* func, TTuple<TReturns...>& outParams, TArgs&&... args)
{
    objClass = obj != nullptr ? obj->GetClass() : objClass;
    UObject* context = obj != nullptr ? obj : objClass;
    uint8* outPramsBuffer = (uint8*)&outParams;

    if (func->HasAnyFunctionFlags(FUNC_Native)) //quick path for c++ functions
    {
        TTuple<TArgs..., TReturns...> params(Forward<TArgs>(args)..., TReturns()...);
        context->ProcessEvent(func, &params);
        //copy back out params
        for (TFieldIterator<UProperty> i(func); i; ++i)
        {
            UProperty* prop = *i;
            if (prop->PropertyFlags & CPF_OutParm)
            {
                void* propBuffer = prop->ContainerPtrToValuePtr<void*>(&params);
                prop->CopyCompleteValue(outPramsBuffer, propBuffer);
                outPramsBuffer += prop->GetSize();
            }
        }
        return;
    }

    TTuple<TArgs...> inParams(Forward<TArgs>(args)...);
    void* funcPramsBuffer = (uint8*)FMemory_Alloca(func->ParmsSize);
    uint8* inPramsBuffer = (uint8*)&inParams;

    for (TFieldIterator<UProperty> i(func); i; ++i)
    {
        UProperty* prop = *i;
        if (prop->GetFName().ToString().StartsWith("__"))
        {
            //ignore private param like __WolrdContext of function in blueprint funcion library
            continue;
        }
        void* propBuffer = prop->ContainerPtrToValuePtr<void*>(funcPramsBuffer);
        if (prop->PropertyFlags & CPF_OutParm)
        {
            prop->CopyCompleteValue(propBuffer, outPramsBuffer);
            outPramsBuffer += prop->GetSize();
        }
        else if (prop->PropertyFlags & CPF_Parm)
        {
            prop->CopyCompleteValue(propBuffer, inPramsBuffer);
            inPramsBuffer += prop->GetSize();
        }
    }

    context->ProcessEvent(func, funcPramsBuffer);   //call function
    outPramsBuffer = (uint8*)&outParams;    //reset to begin

    //copy back out params
    for (TFieldIterator<UProperty> i(func); i; ++i)
    {
        UProperty* prop = *i;
        if (prop->PropertyFlags & CPF_OutParm)
        {
            void* propBuffer = prop->ContainerPtrToValuePtr<void*>(funcPramsBuffer);
            prop->CopyCompleteValue(outPramsBuffer, propBuffer);
            outPramsBuffer += prop->GetSize();
        }
    }
}
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#include "OutputDevice.h"
	FString cmd = FString::Printf(TEXT("TestFun HelloWorld"));
	FOutputDeviceDebug device;
	实例对象->CallFunctionByNameWithArguments(*cmd, device, NULL, true);
//调用通过蓝图actor调用蓝图函数
void AMyActor::CallActorFunc(AActor * c, FString funcName)
{
	FOutputDeviceNull ar;
	c->CallFunctionByNameWithArguments(*funcName, ar, NULL, true);
}


我这边调用天气蓝图插件测试

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#include <Misc/OutputDeviceDebug.h>
	FOutputDeviceDebug device;
	static ConstructorHelpers::FObjectFinder<UBlueprint> UnitSelector(TEXT("Blueprint'/Game/UltraDynamicSky/Blueprints/Ultra_Dynamic_Weather.Ultra_Dynamic_Weather_C'"));
	TSubclassOf<AActor> UnitSelectorClass = (UClass*)UnitSelector.Object->GeneratedClass;
	TArray<AActor*> OutActors;
	UGameplayStatics::GetAllActorsOfClass(GetWorld(), UnitSelectorClass, OutActors);
	AActor* actor = OutActors[0];
	actor->CallFunctionByNameWithArguments(TEXT("TestFun HelloWorld"), device, NULL, true);

https://zhuanlan.zhihu.com/p/61042237
https://www.unrealengine.com/en-US/search?x=0&y=0&filter=All&keyword=CallFunctionByNameWithArguments
https://docs.unrealengine.com/5.0/en-US/API/Runtime/CoreUObject/UObject/UObject/CallFunctionByNameWithArguments/
https://blog.csdn.net/qq_35014708/article/details/84569831