Unreal Engine 4 问题：在打包时使用C++代码加载Blueprint

Myth丶恋晨 2022-05-14 12:10 704阅读 0赞

通过Editor创建好Blueprint后，经常需要在C++代码中控制Blueprint的实例的创建，一般方式如下：

如果是在Editor中运行，可采用如下方式加载Blueprint：

static struct ConstructorHelpers::FObjectFinder<UBlueprint> BP_Model(TEXT("Blueprint'/Game/Blueprint/BP_Model.BP_Model'"));
    if (BP_Model.Succeeded()) {
        UClass* ModelClass = BP_Model.Object->GeneratedClass;
    }

但以上方式得到的类是Blueprint Generated Class。在打包后，运行会报如下错误：

Error: CDO Constructor: Failed to find Blueprint'/Game/Blueprint/BP_Model.BP_Model'

原因是打包后使用上述路径找不到Blueprint，修改方式如下：

static struct ConstructorHelpers::FObjectFinder<UClass> BP_Model(TEXT("Class'/Game/Blueprint/BP_Model.BP_Model_C'"));
    if (BP_Model.Object) {
        UClass* ModelClass = BP_Model.Object;
        UE_LOG(LogTemp, Log, TEXT("BP_ModelClass: %s"), *BP_Model.Object->GetFullName());
    }

路径由"Blueprint'/Game/Blueprint/BP\_Model.BP\_Model'"更改为"Class'/Game/Blueprint/BP\_Model.BP\_Model\_C'"，"\_C"要加入到Blueprint名字后，这是Blueprint类的命名规范。上述执行结果为：

**BP\_ModelClass: BlueprintGeneratedClass /Game/Blueprint/BP\_Model.BP\_Model\_C**

然后就可以通过如下C++代码创建Blueprint的实例：

UWorld* World = GetWorld();
    if (World)
    {
        AModel* Model = World->SpawnActor<AModel>(ModelClass, Location, Rotation);
    }

参考文档：

[https://answers.unrealengine.com/questions/84880/cdo-constructor-failed-to-find-blueprint-ue-44.html][https_answers.unrealengine.com_questions_84880_cdo-constructor-failed-to-find-blueprint-ue-44.html]  
[https://answers.unrealengine.com/questions/130256/whats-the-correct-way-to-load-blueprints-for-packa.html][https_answers.unrealengine.com_questions_130256_whats-the-correct-way-to-load-blueprints-for-packa.html]  
[https://answers.unrealengine.com/questions/127212/bdontloadblueprintoutsideeditortrue-by-default.html][https_answers.unrealengine.com_questions_127212_bdontloadblueprintoutsideeditortrue-by-default.html]

[https_answers.unrealengine.com_questions_84880_cdo-constructor-failed-to-find-blueprint-ue-44.html]: https://answers.unrealengine.com/questions/84880/cdo-constructor-failed-to-find-blueprint-ue-44.html
[https_answers.unrealengine.com_questions_130256_whats-the-correct-way-to-load-blueprints-for-packa.html]: https://answers.unrealengine.com/questions/130256/whats-the-correct-way-to-load-blueprints-for-packa.html
[https_answers.unrealengine.com_questions_127212_bdontloadblueprintoutsideeditortrue-by-default.html]: https://answers.unrealengine.com/questions/127212/bdontloadblueprintoutsideeditortrue-by-default.html