如果没有@Annex-annotated方法，则无法提供Dagger-android构建错误

Question

我正在学习匕首依赖注射（我知道我迟到了，现在开始更好）。

但我面临以下错误。如有任何帮助或建议，我们将不胜感激。

错误日志

    error: [Dagger/MissingBinding] [dagger.android.AndroidInjector.inject(T)] @com.mypackage.di.key.ItemDetail java.lang.Integer cannot be provided without an @Provides-annotated method.
public interface ApplicationComponent extends AndroidInjector<RetailShopApplication> {
   ^
  @com.mypackage.di.key.ItemDetail java.lang.Integer is injected at
      com.mypackage.ui.detail.ItemDetailViewModel.<init>(…, itemId)
  com.mypackage.ui.detail.ItemDetailViewModel is injected at
      com.mypackage.di.module.ViewModelModule.provideItemDetailViewModel(itemDetailViewModel)
  java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
      com.mypackage.viewModel.ViewModelFactory.<init>(creators)
  com.mypackage.viewModel.ViewModelFactory is injected at
      com.mypackage.ui.home.ItemCategoryFragment.itemViewFactory
  com.mypackage.ui.home.ItemCategoryFragment is injected at
      dagger.android.AndroidInjector.inject(T)
component path: com.mypackage.di.component.ApplicationComponent ? com.mypackage.di.builder.ActivityBuilder_ContributeHomeActivity.HomeActivitySubcomponent ? com.mypackage.ui.home.HomeFragmentProvider_ContributeItemCategoryFragment.ItemCategoryFragmentSubcomponent

我的问题

我在ViewModelModule中创建了一个带有contribAndroidInjection批注的provideItemDetailViewModel（），但是ItemDetailViewModel构造函数有一个整数值。

所以我在运行时从我的活动意图到ItemDetailActivityModule类提供一个整数值。问题是匕首给我一个错误“整数已经存在于范围内”但是无法注入ViewModel构造函数。

ViewModelModule

@Module
public abstract class ViewModelModule {

@Binds
@IntoMap
@ViewModelKey(ItemCategoryViewModel.class)
abstract ViewModel provideItemCategoryViewModel(ItemCategoryViewModel 
itemCategoryViewModel);

@Binds
@IntoMap//<---- Here is the new ViewModel
@ViewModelKey(ItemDetailViewModel.class)
abstract ViewModel provideItemDetailViewModel(ItemDetailViewModel 
itemDetailViewModel);

@Binds
abstract ViewModelProvider.NewInstanceFactory 
getViewModelFactory(ViewModelFactory viewModelFactory);
}

项目细节视图模型

@Inject
  public ItemDetailViewModel(Application application, @ItemDetail int itemId) 
  {
        itemRepository = new ItemRepository(application);
        itemLiveData = itemRepository.getItem(itemId);
    }

ItemDetailActivityModule

@Module
public class ItemDetailActivityModule {

  @Provides
  @ItemDetail
  int provideItemId(ItemDetailActivity itemDetailActivity) {
    return itemDetailActivity.getIntent().getIntExtra(AppConstants.ITEM_ID, 
  0);
  }

}

ActivityBuilder

@Module
public abstract class ActivityBuilder {

@ActivityScope
@ContributesAndroidInjector(modules = {HomeFragmentProvider.class, 
HomeActivityModule.class})
abstract HomeActivity contributeHomeActivity();

@ActivityScope
@ContributesAndroidInjector(modules = ItemDetailActivityModule.class)
abstract ItemDetailActivity contributeItemDetailActivity();

}

ApplicationComponent

@Singleton
@Component(modules = {AndroidSupportInjectionModule.class, 
ApplicationModule.class, ActivityBuilder.class})
public interface ApplicationComponent extends 
AndroidInjector<RetailShopApplication> {

  @Component.Builder
  abstract class Builder extends 
  AndroidInjector.Builder<RetailShopApplication> {
  }

}

ApplicationModule

@Module(includes = ViewModelModule.class)
public class ApplicationModule {

   @Provides
   Application provideApplication(RetailShopApplication application) {
    return application;
   }
}

Answer 1

Solution

问题是我正在为ViewModelModule类中的每个ViewModel创建提供程序，该类包含在AppModule中。

使用@ContributeAndroidInjection创建的每个Activity都是一个子组件。

所以App组件和Activity子组件是不同的。 Activity组件可以访问App组件的提供者但反之亦然，注入的原因已经存在错误

我解决了问题，包括活动模块内的视图模型而不是appcomponent模块。

ViewModelModule

之前

@Module
public abstract class ViewModelModule {

   @Binds
   @IntoMap//<---- Here is the new ViewModel
   @ViewModelKey(ItemDetailViewModel.class)
   abstract ViewModel provideItemDetailViewModel(ItemDetailViewModel 
   itemDetailViewModel);

   @Binds
   abstract ViewModelProvider.NewInstanceFactory 
   getViewModelFactory(ViewModelFactory viewModelFactory);
}

之后 - 在ViewModelModule中只需要ViewModelFactory将所有ViewModel提供程序移动到活动模块。

@Module
public abstract class ViewModelModule {

   @Binds
   abstract ViewModelProvider.NewInstanceFactory 
   getViewModelFactory(ViewModelFactory viewModelFactory);
}

ItemDetailProvider

创建Abstract类以保存ViewModel提供程序

@Module
public abstract class ItemDetailProvider {

  @Binds
  @IntoMap
  @ViewModelKey(ItemDetailViewModel.class)
  abstract ViewModel provideItemDetailViewModel(ItemDetailViewModel 
  itemDetailViewModel);

}

ActivityModule

现在在Activity模块中添加创建的提供程序，如下所示

之前

@Module
public abstract class ActivityBuilder {

   @ContributesAndroidInjector(modules = 
   {ItemDetailActivityModule.class})
   abstract ItemDetailActivity contributeItemDetailActivity();

}

之后 - 现在添加与上述活动对应的ViewModel，在我的情况下，它是Item Detail ViewModel类

@Module
public abstract class ActivityBuilder {

   @ContributesAndroidInjector(modules = 
   {ItemDetailActivityModule.class,ItemDetailProvider.class})//<--- provider added in this line
   abstract ItemDetailActivity contributeItemDetailActivity();

}