问组件中存在具有匹配键的dagger错误绑定
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Stack Overflow用户

提问于 2021-11-03 00:07:05

回答 1查看 91关注 0票数 0

Dagger 2

/di/AppComponent.java:19: error: [Dagger/MissingBinding] ProductListFragment cannot be provided without an @Inject constructor or an @Provides-annotated method. This type supports members injection but cannot be implicitly provided.
public abstract interface AppComponent {
                ^
  A binding with matching key exists in component: MainFragmentProvider_BindProductListFragment.ProductListFragmentSubcomponent
      ProductListFragment is injected at
          productlist.ProductListModule.provideChildFragmentManager(productListFragment)
      androidx.fragment.app.FragmentManager is injected at
          productlist.adapter.NewProductListPagerAdapter(…, fragmentManager)
      productlist.adapter.NewProductListPagerAdapter is injected at
          productlist.ProductListV2Fragment.mPagerAdapter
      productlist.ProductListV2Fragment is injected at
          dagger.android.AndroidInjector.inject(T) [di.AppComponent → di.BuilderModule_BindMainActivity.MainActivitySubcomponent →  MainFragmentProvider_BindProductListV2Fragment.ProductListV2FragmentSubcomponent]

我有以下模块，其中包含这两个片段：

@Module
abstract class FragmentProvider {
    @PerFragment
    @ContributesAndroidInjector(modules = [ProductListModule::class])
    abstract fun bindProductListV2Fragment(): ProductListV2Fragment
    
    @PerFragment
    @ContributesAndroidInjector(modules = [ProductListModule::class])
    abstract fun bindProductListFragment(): ProductListFragment
}

在我的ProductListModule中，我有以下内容：

@Module
class ProductListModule {

    @Provides
    fun provideChildFragmentManager(productListFragment: ProductListFragment) =
        productListFragment.childFragmentManager
}

fragmentManager将被注入到以下类中：

class NewProductListPagerAdapter @Inject constructor(
    @ActivityContext private val context: Context,
    fragmentManager: FragmentManager
) { ..... }

这两个片段都会将这个NewProductListPagerAdapter注入其中。

class ProductListV2Fragment  : BaseProductListFragment() {

    @Inject
    lateinit var mPagerAdapter: NewProductListPagerAdapter
}

class ProductListFragment  : BaseProductListFragment() {

    @Inject
    lateinit var mPagerAdapter: NewProductListPagerAdapter
}

我的AppComponent：

@Singleton
@Component(
    modules = [
        AndroidSupportInjectionModule::class,
        AppModule::class,
        ProductModule::class,
        BaseAppModule::class
    ]
)
interface AppComponent {
    @Component.Factory
    interface Factory {
        fun create(
            @BindsInstance application: Application,
        ): AppComponent
    }

    fun inject(tsApplication: TsApplication)
}

====更新====

@Module
abstract class FragmentProvider {

    @PerFragment
    @ContributesAndroidInjector(modules = [ProductListModule::class, ProductListBindingModule::class])
    abstract fun bindProductListFragment(): ProductListFragment


    @PerFragment
    @ContributesAndroidInjector(modules = [ProductListModule::class, ProductListV2BindingModule::class])
    abstract fun bindProductListV2Fragment(): ProductListV2Fragment
}

@Module
class ProductListModule {

    @Provides
    fun provideChildFragmentManager(productListFragment: Fragment): FragmentManager =
        productListFragment.childFragmentManager
}


@Module
abstract class ProductListBindingModule {
    @Binds
    abstract fun bindFragment(fragment: ProductListFragment): Fragment
}

@Module
abstract class ProductListV2BindingModule {
    @Binds
    abstract fun bindFragment(fragment: ProductListV2Fragment): Fragment
}

堆栈跟踪在下面，这表明片段被多次绑定。原因是因为每个片段都注入了以下依赖：

@Inject
lateinit var mPagerAdapter: NewProductListPagerAdapter

在NewProductListPagerAdapter构造函数中：

class NewProductListPagerAdapter @Inject constructor(
    @ActivityContext private val context: Context,
    fragmentManager: FragmentManager
)

它需要提供FragmentManager；

app/build/tmp/kapt3/stubs/uatDebug/tech/central/tops/di/AppComponent.java:22: error: [Dagger/DuplicateBindings] androidx.fragment.app.Fragment is bound multiple times:
public abstract interface AppComponent {
      @org.jetbrains.annotations.NotNull @Binds androidx.fragment.app.Fragment productlist.ProductListBindingModule.bindFragment(productlist.ProductListFragment)
      @org.jetbrains.annotations.NotNull @Binds androidx.fragment.app.Fragment productlist.ProductListV2BindingModule.bindFragment(productlist.ProductListV2Fragment)
      androidx.fragment.app.Fragment is injected at
          authentication.usecase.FacebookLoginUseCase(fragment, …)
      authentication.usecase.FacebookLoginUseCase is injected at
          authentication.usecase.SocialLoginUseCase(…, facebookLoginUseCase, …)
      authentication.usecase.SocialLoginUseCase is injected at
          authentication.FacebookLoginViewModel(…, socialLoginUseCase, …)
      authentication.FacebookLoginViewModel is injected at
          authentication.FacebookLoginViewModelModule.facebookViewModelChildFactory(facebookLoginViewModel)
      java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
          di.factory.ViewModelProviderFactory(classToViewModel)
      di.factory.ViewModelProviderFactory is injected at
          .authentication.login.LoginFragment.mViewModelChildFactory
      authentication.login.LoginFragment is injected at
          dagger.android.AndroidInjector.inject(T) [tech.central.tops.di.AppComponent → di.BuilderModule_BindMainActivity.MainActivitySubcomponent → FragmentProvider_BindLoginFragment.LoginFragmentSubcomponent]

android

dagger-2

回答 1

Stack Overflow用户

发布于 2021-11-05 12:51:50

您的模块依赖于ProductListFragment来获取一个子FragmentManager。但是，相同模块也用于注入ProductListV2Fragment，此时没有可用的ProductListFragment。

为了重用该模块，您需要将对ProductListFragment的依赖拆分为单独的模块。此模块应用于ProductListFragment，类似的模块应用于ProductListV2Fragment。在这些模块中，您可以直接提供FragmentManager，也可以将这两个片段绑定到一个公共超类，如Fragment或BaseProductListFragment。

如果将两个片段都绑定到Fragment，结果代码将如下所示：

@Module
abstract class FragmentProvider {
    @PerFragment
    @ContributesAndroidInjector(modules = [
        ProductListModule::class,
        ProductListV2BindingModule::class
    ])
    abstract fun bindProductListV2Fragment(): ProductListV2Fragment
    
    @PerFragment
    @ContributesAndroidInjector(modules = [
        ProductListModule::class,
        ProductListBindingModule::class
    ])
    abstract fun bindProductListFragment(): ProductListFragment
}

@Module
class ProductListModule {

    @Provides
    fun provideChildFragmentManager(productListFragment: Fragment) =
        productListFragment.childFragmentManager
}

@Module
abstract class ProductListBindingModule {
    @Binds
    fun bindFragment(fragment: ProductListFragment): Fragment
}

@Module
abstract class ProductListV2BindingModule {
    @Binds
    fun bindFragment(fragment: ProductListV2Fragment): Fragment
}

至于错误消息本身，它告诉您三件事：

生成的ProductListV2FragmentSubcomponent需要ProductListFragment，但它没有可用的绑定。
该子组件可能能够将依赖项注入现有的ProductListFragment。这在其他情况下可能是有用的信息，但它与您正在尝试做的事情无关。
您的应用程序中有一个组件可以提供ProductListFragment。具体地说，这是生成的ProductListFragmentSubcomponent，它在其工厂中接受一个ProductListFragment。