kotlin 中的 Dagger2 编译问题

Question

我正在尝试使用 Dagger2 学习依赖注入。我创建了一些自定义范围和限定符。我创建了一个应用程序组件，我想在其中注入某些全局依赖项，并且我还创建了一个 Activity 组件，它将根据活动上下文返回某些实例。

现在，当我尝试在 Activity 中注入全局实例时，出现如下错误：

e: /home/arifur/source_code/me/myprojects/Learn/studio/Android/kotlin/FirebaseChat/app/build/tmp/kapt3/stubs/debug/com/example/arifur/firebasechatkotlin/dependecies/component/ActivityComponent.java:7 ： 错误：无法提供 com.google.firebase.auth.FirebaseAuth 没有 @Provides- 或 @Produces-annotated 方法。 e:

e: 公共抽象无效 注入(@org.jetbrains.annotations.NotNull() e:
^ e: com.google.firebase.auth.FirebaseAuth 在 e:
注入 com.example.arifur.firebasechatkotlin.BaseActivity.firebaseAuth e:
com.example.arifur.firebasechatkotlin.MainActivity 在 e:
注入 com.example.arifur.firebasechatkotlin.dependecies.component.ActivityComponent.inject(p0)

w: 警告：以下选项未被任何人识别 处理器：'[kapt.kotlin.generated]' w：

e: /home/arifur/source_code/me/myprojects/Learn/studio/Android/kotlin/FirebaseChat/app/src/main/java/com/example/arifur/firebasechatkotlin/BaseActivity.kt： (29, 9): 未解决的参考: DaggerActivityComponent e: /home/arifur/source_code/me/myprojects/Learn/studio/Android/kotlin/FirebaseChat/app/src/main/java/com/example/arifur/firebasechatkotlin/FirebaseChatApp.kt： (20, 13): 未解决的参考: DaggerFirebaseComponent e: /home/arifur/source_code/me/myprojects/Learn/studio/Android/kotlin/FirebaseChat/app/src/main/java/com/example/arifur/firebasechatkotlin/MainActivity.kt： (1, 1)：处理注释时发生一些错误。请 请参阅上面的错误消息。

---

预选赛

ActivityContext.kt

@Qualifier
@Retention(AnnotationRetention.RUNTIME)
annotation class ActivityContext

ApplicationContext.kt

@javax.inject.Qualifier
@Retention(AnnotationRetention.RUNTIME)
annotation class ApplicationContext

---

范围

ActivityScope.kt

@Scope
@Retention(AnnotationRetention.SOURCE)
annotation class ApplicationScope

ApplicationScope.kt

@Scope
@Retention(AnnotationRetention.SOURCE)
annotation class ApplicationScope

---

组件

ActivityComponent.kt用于注入Activity类。

@ActivityScope
@Component(modules = arrayOf(ActivityModule::class), dependencies = arrayOf(FirebaseComponent::class))
interface ActivityComponent {
    fun inject(mainActivity: MainActivity)
}

FirebaseComponent.kt用于注入Application类。

@ApplicationScope
@Component(modules = arrayOf(ApplicationModule::class, FirebaseAuthModule::class, NetworkModule::class))
interface FirebaseComponent {
    fun inject(app: FirebaseChatApp)
}

---

模块

ActivityModule.kt

@Module
class ActivityModule(val activity : Activity) {
    var mActivityRef : WeakReference<Activity> ;
    init {
        mActivityRef = WeakReference<Activity>(activity)
    }

    @Provides
    @ActivityScope
    @ActivityContext
    public fun getActivityContext() : Context? = mActivityRef.get()

    @Provides
    @ActivityScope
    @ActivityContext
    public fun getActivityInstance() : Activity? = mActivityRef.get();


    @Provides
    @ActivityScope
    public fun getGlideActivityInstance(@ActivityContext context : Context?) : Glide {
        Log.i("activityModule", "Returning activity glide")
        return Glide.get(context);
    }

}

ApplicationModule.kt

@Module
class ApplicationModule(val app : FirebaseChatApp) {

    @ApplicationContext
    @ApplicationScope
    @Provides
    fun provideContext() : Context = app


    @ApplicationInstance
    @ApplicationScope
    @Provides
    fun provideApplication() : Application = app
}

FirebaseAuthModule.kt

@Module
class FirebaseAuthModule {

    @Provides
    @ApplicationScope
    public fun getFirebaseAuth() : FirebaseAuth = FirebaseAuth.getInstance()
}

NetworkModule.kt

@Module
class NetworkModule {

    @Provides
    @ApplicationScope
    public fun getGlideApplicationInstance(@ApplicationContext applicationContext: Context ) : Glide {
        return Glide.get(applicationContext);
    }
}

FirebaseChatApp.kt一个应用程序类

class FirebaseChatApp : Application() {

        val firebaseComponent: FirebaseComponent by lazy {
            DaggerFirebaseComponent
                    .builder()
                    .applicationModule(ApplicationModule(this))
                    .build()
        }

    @Inject
    lateinit var firebaseAuth : FirebaseAuth

    @Inject
    lateinit var glide : Glide


    override fun onCreate() {
        super.onCreate()
        firebaseComponent.inject(this)
        Log.i("application", "APP->Firebase Auth = " + firebaseAuth)
        Log.i("application", "APP->Glide = " + glide)
    }

    public fun getApplicationComponent() : FirebaseComponent = firebaseComponent;
}

BaseActivity.kt所有活动的超类

public abstract class BaseActivity : AppCompatActivity(){
    @Inject
    @ActivityScope
    protected lateinit var glide : Glide

    @Inject
    @ApplicationScope
    protected lateinit var firebaseAuth : FirebaseAuth //ERROR HERE

    protected val activityComponent: ActivityComponent by lazy {
        DaggerActivityComponent
                .builder()
                .activityModule(ActivityModule(this))
                .firebaseComponent((this.application as FirebaseChatApp).getApplicationComponent())
                .build()
    }


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        injectComponent(activityComponent)
    }
     abstract fun injectComponent(activityComponent: ActivityComponent)
}

MainActivity.kt应该在哪里注入对象。

class MainActivity : BaseActivity() {


    override fun injectComponent(activityComponent: ActivityComponent) {
        activityComponent.inject(this)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)
    }
}

我应该怎么做才能解决这个错误。以及使用DI的正确方法是什么。因为我是新手。我有点糊涂了。

Answer 1

问题是您正在尝试使用组件依赖项，但您已跳过添加子范围组件可以继承的配置方法。

@ApplicationScope
@Component(modules = arrayOf(ApplicationModule::class, FirebaseAuthModule::class, NetworkModule::class))
interface FirebaseComponent {
    fun firebaseAuth() : FirebaseAuth // <-- this is missing

    fun inject(app: FirebaseChatApp)
}