如果没有 @Provides-annotated 方法，则无法提供，组件中存在具有匹配键的绑定

Question

我正在尝试在种子项目中添加 dagger2 以学习目的（我不是专家），但我遇到了同样的问题：

e: /Users/foca/projects/personalProjects/bar-droid-application/bar-droid/app/build/tmp/kapt3/stubs/debug/com/bar/bar_droid/di/AppComponent.java:8: error: [Dagger/MissingBinding] com.bar.bar_droid.domain.repository.RegisterRepository cannot be provided without an @Provides-annotated method. public abstract interface AppComponent extends dagger.android.AndroidInjector { ^ A binding with matching key exists in component: com.bar.bar_droid.ui.accessflow.di.AccessScreenProvider_ProvideRoleSelectorFragmentFactory.RoleSelectionFragmentSubcomponent com.bar.bar_droid.domain.repository.RegisterRepository is injected at com.bar.bar_droid.domain.interactor.userregistration.UserRegistrationUseCase(registerRepository, …) com.bar.bar_droid.domain.interactor.userregistration.UserRegistrationUseCase is injected at com.bar.bar_droid.ui.accessflow.roleselector_fragment.viewmodel.RoleSelectionViewModel(…, userRegistrationUseCase) com.bar.bar_droid.ui.accessflow.roleselector_fragment.viewmodel.RoleSelectionViewModel is injected at com.bar.bar_droid.ui.di.ViewModelModule.provideRoleSelectionViewModel(roleSelectionViewModel) java.util.Map,javax.inject.Provider> is injected at com.bar.bar_droid.utils.mvvm.ViewModelFactory(creators) com.bar.bar_droid.utils.mvvm.ViewModelFactory is injected at com.bar.bar_droid.ui.accessflow.loginselector_fragment.LoginFragment.viewModelFactory com.bar.bar_droid.ui.accessflow.loginselector_fragment.LoginFragment is injected at dagger.android.AndroidInjector.inject(T) [com.bar.bar_droid.di.AppComponent → com.bar.bar_droid.di.ActivityBuilderModule_BindAccessActivity.AccessActivitySubcomponent → com.bar.bar_droid.ui.accessflow.di.AccessScreenProvider_ProvideLoginSelectorFragmentFactory.LoginFragmentSubcomponent] It is also requested at: com.bar.bar_droid.domain.interactor.userregistration.UserRegistrationUseCase(registerRepository, …) The following other entry points also depend on it: dagger.android.AndroidInjector.inject(T) [com.bar.bar_droid.di.AppComponent → com.bar.bar_droid.di.ActivityBuilderModule_BindAccessActivity.AccessActivitySubcomponent → com.bar.bar_droid.ui.accessflow.di.AccessScreenProvider_ProvideMailPasswordFragmentFactory.MailPasswordSignUpFragmentSubcomponent] dagger.android.AndroidInjector.inject(T) [com.bar.bar_droid.di.AppComponent → com.bar.bar_droid.di.ActivityBuilderModule_BindMainActivity.MainActivitySubcomponent → com.bar.bar_droid.ui.mainflow.di.MainFlowProvider_ProvideMenuFragmentFactory.MenuFragmentSubcomponent]

这是我的代码：

申请：

class MainApplication : Application(), HasAndroidInjector {

    @Inject lateinit var androidInjector : DispatchingAndroidInjector<Any>

    override fun onCreate() {
        super.onCreate()

        // Starts Dagger
        DaggerAppComponent.builder()
            .application(this)
            .build()
            .inject(this)
    }

    override fun androidInjector(): AndroidInjector<Any> = androidInjector
}

匕首组件：

@Singleton
@Component(
    modules = [AndroidSupportInjectionModule::class,
        ApplicationModule::class,
        RoomDatabaseModule::class,
        FirebaseModule::class,
        GoogleModule::class,
        ActivityBuilderModule::class]
)
interface AppComponent : AndroidInjector<MainApplication> {

    @Component.Builder
    interface Builder {
        @BindsInstance
        fun application(app: Application): Builder
        fun build(): AppComponent
    }
}

ActivityBuilderModule:

@Module
abstract class ActivityBuilderModule {

    @PerActivity
    @ContributesAndroidInjector(modules = [AccessScreenProvider::class, AccessScreenDependencyProvider::class])
    abstract fun bindAccessActivity(): AccessActivity

    @PerActivity
    @ContributesAndroidInjector(modules = [MainFlowProvider::class])
    abstract fun bindMainActivity(): MainActivity
}

AccessActivity 的片段：

@Module
abstract class AccessScreenProvider {

    @PerFragment
    @ContributesAndroidInjector(modules = [ViewModelModule::class, LoginSelectorProvider::class])
    abstract fun provideLoginSelectorFragmentFactory(): LoginFragment

    @PerFragment
    @ContributesAndroidInjector(modules = [ViewModelModule::class])
    abstract fun provideMailPasswordFragmentFactory(): MailPasswordSignUpFragment

    @PerFragment
    @ContributesAndroidInjector(modules = [ViewModelModule::class, RoleSelectionProvider::class])
    abstract fun provideRoleSelectorFragmentFactory(): RoleSelectionFragment
}

ViewModelModule:

@Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER)
@Retention(AnnotationRetention.RUNTIME)
@MapKey
internal annotation class ViewModelKey(val value: KClass<out ViewModel>)

@Module
abstract class ViewModelModule {

    @Binds
    abstract fun provideViewModelFactory(factory: ViewModelFactory): ViewModelProvider.Factory

    @Binds
    @PerFragment
    @IntoMap
    @ViewModelKey(LoginViewModel::class)
    abstract fun provideLoginViewModel(loginViewModel: LoginViewModel): ViewModel

    @Binds
    @PerFragment
    @IntoMap
    @ViewModelKey(MailPasswordSignUpViewModel::class)
    abstract fun provideMailPasswordSighUpViewModel(mailPasswordSignUpViewModel: MailPasswordSignUpViewModel): ViewModel

    @Binds
    @PerFragment
    @IntoMap
    @ViewModelKey(RoleSelectionViewModel::class)
    abstract fun provideRoleSelectionViewModel(roleSelectionViewModel: RoleSelectionViewModel): ViewModel
}

最后是 RoleSelectionProvide：

@Module
class RoleSelectionProvider {

    @Provides
    @PerFragment
    fun provideRealAuthDataSource(fireBaseAuth: FirebaseAuth): UserAuthDataSource = RealUserAuthDataSource(fireBaseAuth)

    @Provides
    @PerFragment
    fun provideRegisterRepository(realUserAuthDataSource: RealUserAuthDataSource, userProfileDao: UserProfileDao): RegisterRepository {
        return RegisterRepositoryImpl(realUserAuthDataSource, userProfileDao)
    }
}

我注入 RegisterRepositoryImpl 的唯一地方是 UserRegistrationUseCase，我不知道我在做什么做错了。

Answer 1

你在两个地方使用它很奇怪：ViewModelModule。这很可能是问题和重复键错误。 "A binding with matching key exists in component:"

此外，在 provideMailPasswordFragmentFactory 中，您仅传递 ViewModelModule，但在 provideRoleSelectorFragmentFactory 您正在传递 ViewModelModule 和 RoleSelectionProvider。在第一种情况下，您缺少提供 Repository 的 RoleSelectionProvider 提供的依赖项。

    @PerFragment
    @ContributesAndroidInjector(modules = [ViewModelModule::class])
    abstract fun provideMailPasswordFragmentFactory(): MailPasswordSignUpFragment

    @PerFragment
    @ContributesAndroidInjector(modules = [ViewModelModule::class, RoleSelectionProvider::class])
    abstract fun provideRoleSelectorFragmentFactory(): RoleSelectionFragment

如果没有 @Provides-annotated 方法，则无法提供，组件中存在具有匹配键的绑定

cannot be provided without an @Provides-annotated method, A binding with matching key exists in component

android

dependency-injection

kotlin

dagger

dagger-2