Question

使用Dagger2和ViewModelProvider.Factory注入ViewModel类可以在Kotlin 1.3.21上正常工作，但是当我切换到1.3.30时无法编译。谁能发现我（毫无疑问）做错了什么？

我浏览了类似的问题报告，但是还没有人看到我在Kotlin版本之间看到的结果差异。

可通过以下网址访问项目：https://github.com/alteredworlds/posts

分支“ master”可以正常构建，而“ upgradeKotlinBuildFails”则不能。唯一的变化是将Kotlin从1.3.21移至1.3.30。

代码摘要：

@Singleton
class ViewModelFactory @Inject constructor(
        private val viewModels: MutableMap<Class<out ViewModel>,
                @JvmSuppressWildcards Provider<ViewModel>>) :
        ViewModelProvider.Factory {

    @Suppress("UNCHECKED_CAST")
    override fun <T : ViewModel?> create(modelClass: Class<T>): T = viewModels[modelClass]?.get() as T
}

@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
    internal abstract fun bindViewModelFactory(factory: ViewModelFactory): ViewModelProvider.Factory

    @Binds
    @IntoMap
    @ViewModelKey(PostsActivityViewModel::class)
    internal abstract fun bindPostsActivityViewModel(viewModel: PostsActivityViewModel): ViewModel

    @Binds
    @IntoMap
    @ViewModelKey(PostDetailActivityViewModel::class)
    internal abstract fun bindsPostDetailActivityViewModel(viewModel: PostDetailActivityViewModel): ViewModel
}

@Singleton
@Component(modules = arrayOf(
        AndroidSupportInjectionModule::class,
        RepoModule::class,
        ActivityBuilderModule::class,
        ViewModelModule::class)
)
interface AppComponent {
    fun inject(application: PostsApplication)

    @Component.Builder interface Builder {
        @BindsInstance fun application(application: Application): Builder

        fun build(): AppComponent
    }
}

使用Kotlin 1.3.21构建并运行代码。使用Kotlin 1.3.30，构建结果如下：

Posts/app/build/tmp/kapt3/stubs/debug/com/example/twcgilbert/postsapp/app/di/AppComponent.java:11: error: [Dagger/MissingBinding] java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> cannot be provided without an @Provides-annotated method.
public abstract interface AppComponent {
                ^
      java.util.Map<java.lang.Class<? extends androidx.lifecycle.ViewModel>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is injected at
          com.example.twcgilbert.postsapp.common.di.ViewModelFactory(viewModels)
      com.example.twcgilbert.postsapp.common.di.ViewModelFactory is injected at
          com.example.twcgilbert.postsapp.ui.di.ViewModelModule.bindViewModelFactory$app_debug(factory)
      androidx.lifecycle.ViewModelProvider.Factory is injected at
          com.example.twcgilbert.postsapp.ui.posts.PostsActivity.viewModelFactory
      com.example.twcgilbert.postsapp.ui.posts.PostsActivity is injected at
          dagger.android.AndroidInjector.inject(T) [com.example.twcgilbert.postsapp.app.di.AppComponent → com.example.twcgilbert.postsapp.app.di.ActivityBuilderModule_BindPostsActivity.PostsActivitySubcomponent]
  The following other entry points also depend on it:
      dagger.android.AndroidInjector.inject(T) [com.example.twcgilbert.postsapp.app.di.AppComponent → com.example.twcgilbert.postsapp.app.di.ActivityBuilderModule_BindPostDetailActivity.PostDetailActivitySubcomponent]

Kotlin 1.3.30 Dagger2：如果没有@Provides注释的方法，就无法提供ViewModel

0 个答案: