我已经按照Android架构蓝图Dagger2进行依赖注入:https://github.com/googlesamples/android-architecture/tree/todo-mvp-dagger
现在我想将Adapter注入我的Fragment类:
@ActivityScoped
class MainFragment @Inject
constructor(): DaggerFragment() {
@Inject lateinit var adapter : ArtistAdapter
}
我在模块类中有以下内容:
@Module
abstract class MainModule {
@FragmentScoped
@ContributesAndroidInjector
internal abstract fun mainFragment(): MainFragment
@Module
companion object {
@Provides
@ActivityScoped
@JvmStatic internal fun provideArtistAdapter() = ArtistAdapter()
}
}
但由于某种原因,它无法在RecyclerView中显示数据。当我不使用注射并只使用val adapter = ArtistAdapter()
时,它的工作原理。
使用Dagger2注射时我缺少什么?
附录:
mainFragment
正在实现一个回调作为点击监听器:
interface ArtistClickCallback {
fun onClick(artist: LastFmArtist, poster : ImageView)
}
而且:
class MainFragment : DaggerFragment(), ArtistClickCallback
这里是片段模块:
@Module
class MainFragmentModule {
@Provides
fun provideArtistAdapter(mainFragment: MainFragment) = ArtistAdapter(mainFragment)
}
但是当我从Fragment构造函数中删除@Inject时,我得到以下异常:
error: [Dagger/MissingBinding] com.sample.android.lastfm.ui.main.MainFragment 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 extends dagger.android.AndroidInjector<com.sample.android.lastfm.LastFmApp> {
^
A binding with matching key exists in component: com.sample.android.lastfm.ui.main.MainModule_MainFragment$app_debug.MainFragmentSubcomponent
com.sample.android.lastfm.ui.main.MainFragment is injected at
com.sample.android.lastfm.ui.main.MainActivity.mainFragment
com.sample.android.lastfm.ui.main.MainActivity is injected at
dagger.android.AndroidInjector.inject(T) [com.sample.android.lastfm.di.AppComponent → com.sample.android.lastfm.di.ActivityBindingModule_MainActivity$app_debug.MainActivitySubcomponent]
从Fragment构造函数中删除@Inject并将适配器提供给片段或在适配器中使用inject构造函数
@Module
abstract class MainModule {
@FragmentScoped
@ContributesAndroidInjector(modules = [MyAwesomeFragmentModule::class])
internal abstract fun mainFragment(): MainFragment
}
-
@Module
class MyAwesomeFragmentModule {
@Provides
fun provideArtistAdapter() = ArtistAdapter()
}