Question

MVVM + Dagger2

我对Dagger非常陌生。我经历了许多示例项目并创建了这个项目。

我想知道的是使用下面的代码，如何将数据发送到特定的ViewModels。我知道如何通过创建特定的ViewModelProvider.Factory来做到这一点。但是，当我有通用的Factory类时，该怎么办。

ViewModelModule.Class

@Module
public class ViewModelModule {

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
@MapKey
@interface ViewModelKey {
    Class<? extends ViewModel> value();
}

@Provides
ViewModelFactory viewModelFactory(Map<Class<? extends ViewModel>, Provider<ViewModel>> providerMap) {
    return new ViewModelFactory(providerMap);
}

@Provides
@IntoMap
@ViewModelKey(MyViewModel1.class)
ViewModel viewModel1(FetchDataUseCase1 fetchDataUseCase1) {
    return new MyViewModel1(fetchDataUseCase1);
}

@Provides
@IntoMap
@ViewModelKey(MyViewModel2.class)
ViewModel viewModel2(FetchDataUseCase2 fetchDataUseCase2) {
    return new MyViewModel2(fetchDataUseCase2);
}
}

ViewModelFactory.class

@Singleton
public class ViewModelFactory implements ViewModelProvider.Factory {

private final Map<Class<? extends ViewModel>, Provider<ViewModel>> creators;

@Inject
public ViewModelFactory(Map<Class<? extends ViewModel>, Provider<ViewModel>> creators) {
    this.creators = creators;
}

@NonNull
@SuppressWarnings("unchecked")
@Override
public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
    Provider<? extends ViewModel> creator = creators.get(modelClass);
    if (creator == null) {
        for (Map.Entry<Class<? extends ViewModel>, Provider<ViewModel>> entry : creators.entrySet()) {
            if (modelClass.isAssignableFrom(entry.getKey())) {
                creator = entry.getValue();
                break;
            }
        }
    }
    if (creator == null) {
        throw new IllegalArgumentException("unknown model class " + modelClass);
    }
    try {
        return (T) creator.get();
    } catch (Exception e) {
        throw new RuntimeException(e);
    }
}
}

TIA

使用Dagger时将数据传递到ViewModel

0 个答案: