美好的一天,我在dagger2中有经验,但是我试图获得一些关于Hilt的经验,因此我将通过将演示从Dagger2迁移到Hilt来开始演示应用程序。在我的Dagger应用程序中,我有两个组件ApplicationComponent和ActivityComponent。 ActivityComponent取决于ApplicationComponent,因此我将ActivityComponent编写如下:-
@ActivityScope
@Component(
dependencies = [ApplicationComponent::class],
modules = [ActivityModule::class]
)
interface ActivityComponent {
fun inject(dummyActivity: DummyActivity)
fun inject(dummyActivity2: DummyActivity2)
}
因此我尝试在Hilt中实现相同的行为。我知道Hilt用户永远不会直接定义或实例化Dagger组件。相反,Hilt提供了为我们生成的预定义组件,并且如文档所述,“子组件可以依赖于祖先组件中的任何绑定(bind)”。所以我认为我可以做以下事情,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
}
但是当我尝试构建此代码时,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
所以我在这里想念什么?提前致谢
最佳答案
显然,您没有正确导入ApplicationContext限定符,它应该是dagger.hilt.android.qualifiers.ApplicationContext。