Dagger 2、Cicerone、Kotlin - 注入问题

Question

此代码在 Java 中完美运行，但在 Kotlin

中存在未定义的问题

问题：

error: [Dagger/MissingBinding] ru.terrakok.cicerone.Router cannot be provided without an @Inject constructor or an @Provides-annotated method. public abstract void inject(@org.jetbrains.annotations.NotNull()

ru.terrakok.cicerone.Router is injected at com.setname.dagger2ciceronelearning.presentation.main.MainActivity.mRouter

com.setname.dagger2ciceronelearning.presentation.main.MainActivity is injected at com.setname.dagger2ciceronelearning.di.AppComponent.inject(com.setname.dagger2ciceronelearning.presentation.main.MainActivity)

AppComponent

@Singleton
@Component(modules = arrayOf(NavigationModule::class))
interface AppComponent {

    fun inject(mainActivity: MainActivity)
    fun inject(fragmentOne: FragmentOne)
    fun inject(fragmentTwo: FragmentTwo)

}

导航模块

@Module
class NavigationModule {

    private val firstLevelNavigation: Cicerone<Router> = Cicerone.create()
    private val secondLevelNavigation: Cicerone<Router> = Cicerone.create()

    @Provides
    @Singleton
    @Named(Navigation.ROUTER_FIRST_LEVEL)
    fun provideFirstLevelRouter(): Router = firstLevelNavigation.router

    @Provides
    @Singleton
    @Named(Navigation.ROUTER_SECOND_LEVEL)
    fun provideSecondLevelRouter(): Router = secondLevelNavigation.router

    @Provides
    @Singleton
    @Named(Navigation.NAV_HOLDER_FIRST_LEVEL)
    fun provideFirstLevelNavigatorHolder(): NavigatorHolder = firstLevelNavigation.navigatorHolder


    @Provides
    @Singleton
    @Named(Navigation.NAV_HOLDER_SECOND_LEVEL)
    fun provideSecondLevelNavigationHolder(): NavigatorHolder = secondLevelNavigation.navigatorHolder

}

LearingApp

class LearningApp : Application() {

    companion object {

        lateinit var appComponent: AppComponent

    }

    override fun onCreate() {
        super.onCreate()
        appComponent = DaggerAppComponent
            .builder()
            .build()
    }

}

MainActivity

class MainActivity : AppCompatActivity() {

    @Inject
    @Named(Navigation.ROUTER_FIRST_LEVEL)
    lateinit var mRouter: Router

    @Inject
    @Named(Navigation.NAV_HOLDER_FIRST_LEVEL)
    lateinit var mNavigatorHolder: NavigatorHolder

    private lateinit var mNavigator:Navigator

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        LearningApp.appComponent.inject(this)

        mNavigator = SupportAppNavigator(this, R.id.main_container)

        mRouter.newRootScreen(Screens.FragmentOneScreen())

    }

    override fun onResume() {
        super.onResume()
        mNavigatorHolder.setNavigator(mNavigator)
    }

    override fun onPause() {
        mNavigatorHolder.removeNavigator()
        super.onPause()
    }

}

Answer 1

正如一位非常聪明的人曾经说过的：You need to target the annotation at the field by using @field:Named.

Answer 2

您可以尝试使用自定义限定符：

@Qualifier
@Retention
annotation class RouterFirstLevel

那么你的模块：

@Provides
@Singleton
@RouterFirstLevel
fun provideFirstLevelRouter(): Router = firstLevelNavigation.router

和activity：

@Inject
@RouterFirstLevel
lateinit var mRouter: Router

P.S。不过我同意 jbarat，注释中的字段应该有帮助，尝试使用字符串而不是字符串常量，可能是某种类型不匹配

Dagger 2、Cicerone、Kotlin - 注入问题

Dagger 2, Cicerone, Kotlin - inject problem

android

dependency-injection

kotlin

dagger-2