5.1 KiB
5.1 KiB
Deprecated
- 功能描述： 标明该类已经弃用。
- 引擎模块： Development
- 元数据类型： bool
- 作用机制： 在ClassFlags添加CLASS_Deprecated、CLASS_NotPlaceable，在Meta添加DeprecationMessage、DeprecatedProperty
- 常用程度：★★★
标明该类已经弃用。
弃用会导致：不可被创建，不可被序列化保存，在继承列表里被过滤掉。此说明符子类会继承下来，标明子类也是废弃的。标上Deprecated 的类需要在类名前加上UDEPRECATED_的显眼前缀，但是类名不会变，Actor加ADEPRECATED_，UObject加UDEPRECATED_。ClassFLags里会标上CLASS_Deprecated和CLASS_NotPlaceable。注意还是可以正常NewObject使用的。而SpawnActor会失败，报错： failed because class %s is deprecated。EditInline也都会被禁止。
示例代码1：
UCLASS(Blueprintable)
class INSIDER_API UMyClass_Deprecated :public UObject
{
GENERATED_BODY()
};
//改为：
UCLASS(Blueprintable, Deprecated)
class INSIDER_API UDEPRECATED_MyClass_Deprecated :public UObject
{
GENERATED_BODY()
};
示例效果1：
依然可以NewObject。
示例代码2：
但要注意这个是UE的标记。源码里还看见很多UE_DEPRECATED宏的使用，则是在VS编译器级别的标记，会根据使用引用情况在编译的步骤中生成警告。
UCLASS(Blueprintable, BlueprintType)
class INSIDER_API UMyClass_Deprecated_Test :public UObject
{
GENERATED_BODY()
public:
UE_DEPRECATED(5.2, "MyClass_Deprecated has been deprecated, please remove it.")
UDEPRECATED_MyClass_Deprecated* MyProperty_Deprecated;
UE_DEPRECATED(5.2, "MyIntProperty has been deprecated, please remove it.")
UPROPERTY(EditAnywhere, BlueprintReadWrite,meta=(DeprecatedProperty, DeprecationMessage = "MyIntProperty has been deprecated."))
int MyIntProperty;
UE_DEPRECATED(5.2, "MyClass_Deprecated has been deprecated, please remove it.")
void MyFunc(UDEPRECATED_MyClass_Deprecated* obj){}
UFUNCTION(BlueprintCallable, meta = (DeprecatedProperty, DeprecationMessage="MyVoidFunc has been deprecated."))
void MyVoidFunc(){}
};
UCLASS(Blueprintable, BlueprintType)
class INSIDER_API UMyClass_Deprecated_Usage :public UObject
{
GENERATED_BODY()
public:
void MyFunc()
{
UMyClass_Deprecated_Test* obj=NewObject<UMyClass_Deprecated_Test>();
UDEPRECATED_MyClass_Deprecated* obj2 = NewObject<UDEPRECATED_MyClass_Deprecated>();
obj->MyProperty_Deprecated= obj2;
obj->MyProperty_Deprecated->MyFunc();
obj->MyIntProperty++;
obj->MyFunc(obj2);
obj->MyVoidFunc();
}
};
编译警告：
warning C4996: 'UMyClass_Deprecated_Test::MyProperty_Deprecated': MyClass_Deprecated has been deprecated, please remove it. Please update your code to the new API before upgrading to the next release, otherwise your project will no longer compile.
warning C4996: 'UMyClass_Deprecated_Test::MyProperty_Deprecated': MyClass_Deprecated has been deprecated, please remove it. Please update your code to the new API before upgrading to the next release, otherwise your project will no longer compile.
warning C4996: 'UMyClass_Deprecated_Test::MyIntProperty': MyIntProperty has been deprecated, please remove it. Please update your code to the new API before upgrading to the next release, otherwise your project will no longer compile.
warning C4996: 'UMyClass_Deprecated_Test::MyFunc': MyClass_Deprecated has been deprecated, please remove it. Please update your code to the new API before upgrading to the next release, otherwise your project will no longer compile.
注意如果没有UE_DEPRECATED标记，则不会生成编译警告。
UPROPERTY(EditAnywhere, BlueprintReadWrite) int MyInt2Property_DEPRECATED;
会触发：
warning : Member variable declaration: Deprecated property 'MyInt2Property_DEPRECATED' should not be marked as blueprint visible without having a BlueprintGetter
warning : Member variable declaration: Deprecated property 'MyInt2Property_DEPRECATED' should not be marked as blueprint writable without having a BlueprintSetter
warning : Member variable declaration: Deprecated property 'MyInt2Property_DEPRECATED' should not be marked as visible or editable
因此只能改成：
UPROPERTY() int MyInt2Property_DEPRECATED;
示例效果2：
属性和函数上加上Deprecated标记后，会在BP编译的时候生成警告。注意函数是先有一个正常的函数，在BP里连接完成之后再在C++里标记DeprecatedFunction才会生成警告，否则已经Deprecated的函数是无法再在BP里调用的。
原理：
源码中有众多CLASS_Deprecated的判断，比如SpawnActor：
AActor* UWorld::SpawnActor( UClass* Class, FTransform const* UserTransformPtr, const FActorSpawnParameters& SpawnParameters )
{
if( Class->HasAnyClassFlags(CLASS_Deprecated) )
{
UE_LOG(LogSpawn, Warning, TEXT("SpawnActor failed because class %s is deprecated"), *Class->GetName() );
return NULL;
}
}