android - Hilt 中的组件依赖项

Question

美好的一天，我有使用 dagger2 的经验，但我想在 Hilt 中获得一些经验，所以我从演示应用程序开始，将演示从 Dagger2 迁移到 Hilt。在我的 Dagger 应用程序中，我有两个组件 ApplicationComponent 和 ActivityComponent。 ActivityComponent 依赖于 ApplicationComponent，所以我将 ActivityComponent 编写如下:-

@ActivityScope
@Component(
    dependencies = [ApplicationComponent::class],
    modules = [ActivityModule::class]
)
interface ActivityComponent {
    fun inject(dummyActivity: DummyActivity)
    fun inject(dummyActivity2: DummyActivity2)
}

所以我尝试在 Hilt 中实现相同的行为。我知道 Hilt 用户从不直接定义或实例化 Dagger 组件。相反，Hilt 提供了为我们生成的预定义组件，正如文档所解释的那样“子组件可以依赖于祖先组件中的任何绑定(bind)”

所以我认为我可以执行以下操作，因为 ActivityComponent 是 SingletonComponent/ApplicationComponent 的子级，因此 ActivityComponent 可以访问 ApplicationComponent 中的任何绑定(bind):-

@Module
@InstallIn(ApplicationComponent::class)
class  ApplicationModule {


    @Provides
    @Singleton
    fun provideDispatcherProvider(): DispatcherProvider = FlowDispatcherProvider()

    @Provides
    @Singleton
    fun provideSharedPreferences(@ApplicationContext application: Application): SharedPreferences =
        application.getSharedPreferences("project-prefs", Context.MODE_PRIVATE)

   
    @Provides
    @Singleton
    fun provideNetworkHelper(@ApplicationContext application: Application): NetworkHelper = NetworkHelper(application)

@Provides
@Singleton
fun provideNetworkService(@ApplicationContext application: Application): NetworkService =
        Networking.create(
            BuildConfig.USERNAME,
            BuildConfig.PASSWORD,
            BuildConfig.BASE_URL,
            application.cacheDir,
            10 * 1024 * 1024 // 10MB
        )

}


@Module
@InstallIn(ActivityComponent::class)
class ActivityModule {


    @Provides
    @ActivityScoped
    fun provideMyHelper(
        dispatcherProvider: DispatcherProvider,
        networkHelper: NetworkHelper
       ):MyHelper =  MyHelper(dispatcherProvider, networkHelper)


}

class MyHelper
    (
    private val dispatcherProvider: DispatcherProvider,
    private val networkHelper: NetworkHelper
) {

}

@ActivityScoped
@AndroidEntryPoint
class DummyActivity(): AppCompatActivity() {

    @Inject
    lateinit var myhelper: MyHelper
}

但是当我尝试构建这段代码时，我得到:-

error: [Dagger/MissingBinding] @com.mypackage.ApplicationContext android.app.application cannot be provided without an @Provides-annotated method.
  public abstract static class SingletonC implements MyApplication_GeneratedInjector,
                         ^
      @com.mypackage.ApplicationContext android.app.Application is injected at
          mypackage.module.ApplicationModule.provideNetworkHelper(application)
      com.mypackage.NetworkHelper is injected at
          com.mypackage.ActivityModule.provideMyHelper(�, networkHelper)
      com.mypackage.MyHelper is injected at
          com.mypackage.DummyActivity.myhelper
      com.mypackage.DummyActivity is injected at
      com.mypackage.DummyActivity.myhelper

所以我在这里错过了什么？提前致谢

Answer 1

显然您没有正确导入 ApplicationContext 限定符，它应该是 dagger.hilt.android.qualifiers.ApplicationContext。