没有 @Provides-annotated 方法就无法提供 Dagger/MissingBinding

Question

无法将演示者注入 Activity

BookDashboard -> Activity

class BookDashboard : AppCompatActivity(),BookDashboardContract.MvpView{

    @Inject
    lateinit var presenter: BookDashboardContract.Presenter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        presenter.fetchedBooks() 
        // if I pass no parameter to BookPresenter than UninitializedPropertyAccessException: lateinit property presenter has not been initialized
    }

    override fun displayBooks() {
        Toast.makeText(this,"Books Displayed",Toast.LENGTH_LONG).show()
    }

    override fun showProgress() {}
    override fun hideProgress() {}
}

BookDashboardContract

interface BookDashboardContract {

    interface MvpView{
        fun displayBooks()
        fun showProgress()
        fun hideProgress()
    }

    interface Presenter{
        fun fetchedBooks()
    }
}

BookDashboardPresenter 如果我没有将参数传递给下面的构造函数应用程序将运行但仍然没有注入演示者并在 BookDashboard -> Activity 中的 presenter.fetchBooks() 处崩溃 __ 请参阅该代码中的注释

class BookDashboardPresenter @Inject constructor(val viewContract:BookDashboardContract.MvpView) : BookDashboardContract.Presenter{

    val bookInteractor = BookInteractor(this)

    override fun fetchedBooks() {
        bookInteractor.fetchDataFromServer()
        viewContract.displayBooks()
    }
}

Activity建设者

@Module
abstract class ActivityBuilder {

    @ContributesAndroidInjector(modules = {BookDashboardModule.class})
    @ActivityScope
    public abstract BookDashboard bindBookDashboard();
}

BookDashboardModule

@Module
abstract class BookDashboardModule {

    @Binds
    @ActivityScope
    abstract fun presenter(presenter: BookDashboardPresenter): BookDashboardContract.Presenter
}

Second approach I used. But still presenter isn't injected

 @Module
 class BookDashboardModule(val mvpView: BookDashboardContract.MvpView) {

    @Provides
    @ActivityScope
    fun providesCategoryView(): BookDashboardContract.MvpView {
        return this.mvpView
    }

    @Provides
    @ActivityScope
    fun provideBookPresenter(): BookDashboardPresenter {
        return BookDashboardPresenter(mvpView)
    }
}

@Subcomponent.Factory method is missing parameters for required modules or subcomp

@Module(subcomponents = ActivityBuilder_BindBookDashboard.BookDashboardSubcomponent.class)
public abstract class ActivityBuilder_BindBookDashboard {
  private ActivityBuilder_BindBookDashboard() {}

  @Binds
  @IntoMap
  @ClassKey(BookDashboard.class)
  abstract AndroidInjector.Factory<?> bindAndroidInjectorFactory(
      BookDashboardSubcomponent.Factory builder);

  @Subcomponent(modules = BookDashboardModule.class)
  @ActivityScope
  public interface BookDashboardSubcomponent extends AndroidInjector<BookDashboard> {
    @Subcomponent.Factory
    interface Factory extends AndroidInjector.Factory<BookDashboard> {}
  }
}

编辑

作为 Onik 的评论，我已经用 DaggerAppCompatActivity 替换了 AppCompatActivity 但仍然无法注入 presenter

如果没有@Provides-annotate

，则无法提供 MvpView

/Users/geek/StudioProjects/MyApplication/app/build/tmp/kapt3/stubs/debug/quiz/mania/trivia/mcq/question/di/AppComponent.java:8: error: [Dagger/MissingBinding] quiz.mania.trivia.mcq.question.booksmvp.contract.BookDashboardContract.MvpView cannot be provided without an @Provides-annotated method.
public abstract interface AppComponent extends dagger.android.AndroidInjector<quiz.mania.trivia.mcq.question.App> {
                ^
      quiz.mania.trivia.mcq.question.booksmvp.contract.BookDashboardContract.MvpView is injected at
          quiz.mania.trivia.mcq.question.booksmvp.presenter.BookDashboardPresenter(viewContract)
      quiz.mania.trivia.mcq.question.booksmvp.presenter.BookDashboardPresenter is injected at
          quiz.mania.trivia.mcq.question.di.BookDashboardModule.presenter(presenter)
      quiz.mania.trivia.mcq.question.booksmvp.contract.BookDashboardContract.Presenter is injected at
          quiz.mania.trivia.mcq.question.booksmvp.BookDashboard.presenter
      quiz.mania.trivia.mcq.question.booksmvp.BookDashboard is injected at
          dagger.android.AndroidInjector.inject(T) [quiz.mania.trivia.mcq.question.di.AppComponent → quiz.mania.trivia.mcq.question.di.ActivityBuilder_BindBookDashboard.BookDashboardSubcomponent]

AppComponent

@Component(
    modules = [
        AndroidInjectionModule::class, // why it is necessary to use this class for injecting purpose
        AppModule::class,
        ActivityBuilder::class
    ]
)
@Singleton
interface AppComponent : AndroidInjector<App> {

    @Component.Builder
    interface Builder {

        fun addContext(@BindsInstance context: Context): Builder

        fun build(): AppComponent
    }
}

App.kt

class App : DaggerApplication() {

    override fun applicationInjector(): AndroidInjector<out DaggerApplication> {
        return DaggerAppComponent.builder().addContext(this).build()
    }
}

Answer 1

我认为依赖图有些混乱。请像下面这样更改您的代码，然后重试：

@Module
 class BookDashboardModule {

    @Provides
    @ActivityScope
    fun provideBookPresenter(view: BookDashboard): BookDashboardContract.Presenter = BookDashboardPresenter(view)
}

////////

@Module
abstract class ActivityBuilder {

    @ContributesAndroidInjector(modules = {BookDashboardModule.class})
    @ActivityScope
    abstract fun bind(): BookDashboard
}

/////////

class BookDashboardPresenter @Inject constructor(val view: BookDashboardContract.MvpView) : BookDashboardContract.Presenter{

    val bookInteractor = BookInteractor(this)

    override fun fetchedBooks() {
        bookInteractor.fetchDataFromServer()
        view.displayBooks()
    }
}

没有 @Provides-annotated 方法就无法提供 Dagger/MissingBinding

cannot be provided without an @Provides-annotated method Dagger/MissingBinding

android

kotlin

dagger-2

android-mvp