带有ViewModel的Android Hilt限于Navgraph，提供者工厂问题

如何解决带有ViewModel的Android Hilt限于Navgraph，提供者工厂问题

我正在使用 Hilt 进行依赖项注入，专门用于注入 ViewModel 。 还希望将ViewModel扩展到NavGraph 。为此，通过传递 NavGraph 来获取 ViewModelStoreOwner ，现在通过传递navgraph提供的 store实例来创建 ViewModel strong>改为 ViewModelProvider 。我面临的问题是，因为我仅传递商店实例以获取 ViewModelProvider 而没有任何 Factory ，因为 Hilt 将实现这一目标，我得到构建错误没有零参数构造函数。当看到源代码时，我发现由于我仅提供商店实例作为参数而没有提供工厂，因此会自动提供简单工厂和提供的工厂没有参数，因此会出现此错误。

如何解决此问题？

从源（ViewModelProvider.java）调用的方法-

     * Creates {@code ViewModelProvider}. This will create {@code ViewModels}
     * and retain them in a store of the given {@code ViewModelStoreOwner}.
     * <p>
     * This method will use the
     * {@link HasDefaultViewModelProviderFactory#getDefaultViewModelProviderFactory() default factory}
     * if the owner implements {@link HasDefaultViewModelProviderFactory}. Otherwise,a
     * {@link NewInstanceFactory} will be used.
     */
    public ViewModelProvider(@NonNull ViewModelStoreOwner owner) {
        this(owner.getViewModelStore(),owner instanceof HasDefaultViewModelProviderFactory
                ? ((HasDefaultViewModelProviderFactory) owner).getDefaultViewModelProviderFactory()
                : NewInstanceFactory.getInstance());
    }

需要依赖项注入的我的ViewModel类-

    private Repository repository;
    private MutableLiveData<FeatureCollection> featureCollection = new MutableLiveData<>();
    private MutableLiveData<Boolean> loading = new MutableLiveData<>();
    private Disposable disposable;


    @ViewModelInject
    public QuakeListViewModel(Repository repository) {
        this.repository = repository;
    }

我的片段类-

    private FragmentQuakeListBinding _binding;
    private QuakeListViewModel _viewModel;
    private ViewModelStoreOwner viewModelStoreOwner;
    private NavController _navController;
 @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        _navController = NavHostFragment.findNavController(this);
        viewModelStoreOwner =  _navController.getViewModelStoreOwner(R.id.main_nav_graph);

    }

public View onCreateView(@NotNull LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
        //other implementation
        _viewModel = new ViewModelProvider(viewModelStoreOwner).get(QuakeListViewModel.class);
        //return binding.root
    }

任何帮助将不胜感激

谢谢

解决方法

根据Integration with the Jetpack navigation library documentation：

如果您的ViewModel是scoped to the navigation graph，请使用defaultViewModelProviderFactory对象，该对象可用于以@AndroidEntryPoint注释的活动和片段。

因此您可以使用：

_viewModel = new ViewModelProvider(viewModelStoreOwner,getDefaultViewModelProviderFactory()).get(QuakeListViewModel.class);