伪单例

在UE4中GameInstance实现伪单例，用来控制总体的东西

//===================头文件======================
class DINGMU_API UMyGameInstance : public UGameInstance
{
    GENERATED_BODY()
    virtual void Init();
public:
    static UMyGameInstance* GameInstanceReference;
};

//===================源文件======================
UMyGameInstance* UMyGameInstance::GameInstanceReference=NULL;
void UMyGameInstance::Init()
{
    GameInstanceReference = Cast<UMyGameInstance>(GetWorld()->GetGameInstance());
}