lateinit 属性 ViewModelFactory 尚未初始化

Question

我在我的 android 项目中使用 dagger 2.25.2 和 androidx.lifecycle 进行依赖注入。但是我有错误 ViewModelFactory has not been initialized

这是我的代码

class PropertyActivity : AppCompatActivity() {

    @Inject
    lateinit var propertyViewModelFactory: PropertyViewModelFactory
    lateinit var propertyViewModel: PropertyViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.property_activity)

        propertyViewModel = ViewModelProviders.of(this, propertyViewModelFactory).get(
        PropertyViewModel::class.java)

        propertyViewModel.loadProperties()
}

ViewModelFactory：

class PropertyViewModelFactory @Inject constructor(
    private val propertyViewModel: PropertyViewModel) : ViewModelProvider.Factory {

    override fun <T : ViewModel> create(modelClass: Class<T>): T {
        if (modelClass.isAssignableFrom(PropertyViewModel::class.java!!)) {
            return propertyViewModel as T
        }
        throw IllegalArgumentException("Unknown class name")
    }
}

应用模块：

@Module
class AppModule(val app: Application){

    @Provides
    @Singleton
    fun provideApplication(): Application = app

    @Provides
    @Singleton
    fun providePropertyViewModelFactory(factory: PropertyViewModelFactory): ViewModelProvider.Factory = factory

}

BuildersModule：

@Module
abstract class BuildersModule {

    @ContributesAndroidInjector
    abstract fun contributePropertyActivity(): PropertyActivity
}

应用组件：

@Singleton
@Component(modules = arrayOf(AndroidInjectionModule::class,BuildersModule::class, AppModule::class))interface PlotComponent {

    fun inject(app: Application)
}

应用类：

class PlotApplication : Application(), HasAndroidInjector {
    @Inject
    lateinit var activityInjector: DispatchingAndroidInjector<Any>

    override fun onCreate() {
        super.onCreate()

        DaggerPlotComponent.builder()
            .appModule(AppModule(this))
            .build().inject(this)
    }
    override fun androidInjector(): AndroidInjector<Any> = activityInjector
}

Answer 1

我看不到您在活动中注入依赖项的位置。问题可能出在这。

添加

AndroidInjection.inject(this)

在你的 onCreate 中