我有一个要用作单例的模型(AModel)。我创建了一个名为@ApplicationScope的自定义范围,以将其用于只需要使用一次的每个类。因此,AppComponent和AModel共享此@ApplicationScope。我有一些片段(ConfirmationFragment),我想同时使用AModel和BModel。 BModel具有不同的范围,因为我想在3个片段中使用它,但Amodel到处都需要。
访问AModel和BModel的想法是让ConfirmationComponent依赖于已有AModel的AppComponent。这样,如果我将ConfirmationComponent注入到ConfirmationFragment中,我也可以使用AModel。但是我收到以下错误:[Dagger/IncompatiblyScopedBindings] ConfirmationComponent scoped with @ConfirmationScope may not reference bindings with different scopes:
当从ConfirmationFragment中注释掉注入AModel时,构建成功,但如果不是,则构建失败。我也需要该片段中的AModel。
我该如何解决此问题?(以防万一,这很重要:我只使用一个活动,而让Android导航处理片段。)
open class MyApplication : Application() {
override fun onCreate() {
super.onCreate()
val appComponent = initializeComponent()
}
val appComponent: AppComponent by lazy {
initializeComponent()
}
val confirmationComponent: ConfirmationComponent by lazy {
initializeConfirmationComponent()
}
open fun initializeComponent(): AppComponent {
return DaggerAppComponent.factory().create(applicationContext)
}
open fun initializeConfirmationComponent(): ConfirmationComponent {
return DaggerConfirmationComponent.builder().appComponent(appComponent).build()
}
}
@ApplicationScope
@Component(modules = [NetworkModule::class])
interface AppComponent {
@Component.Factory
interface Factory {
fun create(@BindsInstance context: Context) : AppComponent
}
fun inject(activity: MainActivity)
fun inject(fragment: ConfirmationFragment)
}
@ConfirmationScope
@Component(dependencies = [AppComponent::class])
interface ConfirmationComponent {
fun inject(fragment: ConfirmationFragment)
}
@ApplicationScope
class AModel @Inject constructor() {}
@ConfirmationScope
class BModel @Inject constructor() {}
class ConfirmationFragment : Fragment() {
@Inject
lateinit var modelA : AModel
@Inject
lateinit var modelB : BModel
override fun onAttach(context: Context) {
super.onAttach(context)
(requireActivity().applicationContext as MyApplication).confirmationComponent.inject(this)
}
// Rest of the code
}
投票
我想您应该反过来说。如果我正确地理解了您,ModelA的范围比ModelB大,则意味着您可以将ModelB作为ModelA的子组件,范围更窄。
因此,您需要:
ConfirmationComponent//@YourScopeAnnotation
@Subcomponent(modules = [...]) // if it is dependent on any modules
interface ConfirmationComponent {
// needed for dagger to create component
@Subcomponent.Factory
interface Factory {
fun create(): ConfirmationComponent
}
fun inject(yourFragment: Fragment) // fun inject your fragment
}
SubcomponentsModule
@Module(
subcomponents = [ConfirmationComponent::class]
)
class SubcomponentsModule
在您的ApplicationComponent中
//@ApplicationScopeAnnotation I think you can also use @Singleton
@Component(
modules = [NetworkModule::class, SubcomponentsModule::class]
)
interface ApplicationComponent {
fun inject(activity: MainActivity)
fun confirmationComponent(): ConfirmationComponent.Factory
}
比往常一样,只需在Application类中初始化ApplicationComponent
现在在您的主要活动中注入应该在全球范围内可用的ModelA
@Inject
lateinit var modelA : AModel
override fun onCreate(savedInstanceState: Bundle?) {
modelA = (applicationContext as MyApplication).appComponent.inject(this)
}
最后一步,在片段中注入modelB并从活动中获取modelA
@Inject
lateinit var modelB: ModelB // inject modelB
lateinit var modelA: ModelA // get ModelA from activity where it was already injected
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
(activity?.applicationContext as MyApplication).appComponent.confirmationComponent().create()
.inject(this)
modelA = (activity as MainActivity).modelA
}
我希望这会有所帮助:)