无法将AppModule中提供的对象注入到具有Dagger2的动态功能模块中的活动中

Question

通过下面的设置，我无法将Singleton对象注入动态功能模块内的"活动"。我可以注入到子组件MainActivity，但不能注入到动态功能模块中的Activity。

@Component(modules = [AppModule::class])
interface AppComponent {
fun inject(application: Application)
@Component.Factory
interface Factory {
fun create(@BindsInstance application: Application): AppComponent
}
// Types that can be retrieved from the graph
fun mainActivityComponentFactory(): MainActivitySubComponent.Factory
}

我的应用程序模块

@Module(includes = [AppProviderModule::class])
abstract class AppModule {
@Binds
abstract fun bindContext(application: Application): Context
}
@Module
object AppProviderModule {
@Provides
@Singleton
fun provideSharedPreferences(application: Application): SharedPreferences {
return application.getSharedPreferences("PrefName", Context.MODE_PRIVATE)
}
}

动态功能模块库组件

@GalleryScope
@Component(
dependencies = [AppComponent::class],
modules = [GalleryModule::class])
interface GalleryComponent {
fun inject(galleryActivity: GalleryActivity)
}

和MyApplication

open class MyApplication : Application() {
// Instance of the AppComponent that will be used by all the Activities in the project
val appComponent: AppComponent by lazy {
initializeComponent()
}
open fun initializeComponent(): AppComponent {
// Creates an instance of AppComponent using its Factory constructor
// We pass the applicationContext that will be used as Application
return DaggerAppComponent.factory().create(this).apply {
inject(this@MyApplication)
}
}
}

动态功能模块中的活动，当仅从GalleryModule注入GalleryViewer和DummyDependency时，工作良好

class GalleryActivity : AppCompatActivity() {
@Inject
lateinit var sharedPreferences: SharedPreferences
@Inject
lateinit var galleryViewer: GalleryViewer
@Inject
lateinit var dummyDependency: DummyDependency
override fun onCreate(savedInstanceState: Bundle?) {
DaggerGalleryComponent.builder()
.appComponent((application as MyApplication).appComponent)
.build()
.inject(this)
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_gallery)
}

当我试图注入SharedPreferences或任何不依赖于AppModule中的任何参数(如上下文或应用程序(的依赖项时，我会得到错误

error: [Dagger/MissingBinding] android.content.SharedPreferences cannot be provided without an @Provides-annotated method.

Answer 1

此处的错误不包括AppComponent中依赖项的提供方法以及未正确构建动态功能组件。

@Singleton
@Component(modules = [AppModule::class])
interface AppComponent {
/**
* 🔥🔥🔥 This method is required to get this object from a class that uses this component
* as dependent component
*/
fun provideSharedPreferences(): SharedPreferences
fun inject(application: Application)
@Component.Factory
interface Factory {
fun create(@BindsInstance application: Application): AppComponent
}
// Types that can be retrieved from the graph
fun mainActivityComponentFactory(): MainActivitySubComponent.Factory
}

动态特征

@GalleryScope
@Component(
dependencies = [AppComponent::class],
modules = [GalleryModule::class])
interface GalleryComponent {
fun inject(galleryActivity: GalleryActivity)
// Alternative1 With Builder
@Component.Builder
interface Builder {
fun build(): GalleryComponent
@BindsInstance
fun application(application: Application): Builder
fun galleryModule(module: GalleryModule): Builder
fun appComponent(appComponent: AppComponent): Builder
}
// Alternative2 With Factory
@Component.Factory
interface Factory {
fun create(appComponent: AppComponent,
galleryModule: GalleryModule,
@BindsInstance application: Application): GalleryComponent

}
}

您必须使用Builder或Factory，在将来可能不需要这些，但它还不支持动态功能，我更喜欢工厂模式，因为他们不赞成使用Builder模式。

内部活动onCreate初始化注入

private fun initInjections() {
// Alternative1 With Builder
DaggerGalleryComponent.builder()
.appComponent((application as MyApplication).appComponent)
.application(application)
.galleryModule(GalleryModule())
.build()
.inject(this)
// Alternative2 With Factory
DaggerGalleryComponent
.factory()
.create((application as MyApplication).appComponent, GalleryModule(), application)
.inject(this)
}

您应该选择与功能组件内部使用的模式相同的模式。