unreal engine c++不修改蓝图的情况下调用蓝图多种方式研究

/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, ¶ms);
    return params.ReturnValue;
}
//使用
int r=InvokeFunction(obj,"Func",123.f);

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

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, ¶ms);
        //copy back out params
        for (TFieldIterator<UProperty> i(func); i; ++i)
        {
            UProperty* prop = *i;
            if (prop->PropertyFlags & CPF_OutParm)
            {
                void* propBuffer = prop->ContainerPtrToValuePtr<void*>(¶ms);
                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();
        }
    }
}

#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);
}

​​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/CallFunctionByNameWithArgu​​