AgentSkillsCN

Android Dependency Injection

Android 依赖注入

SKILL.md

name: android-dependency-injection description: Dependency injection with Hilt/Dagger — setup, scoping, multi-module, testing. user-invocable: true

Android Dependency Injection

Cross-cutting skill — always activates alongside the project-type-specific skill.

Hard Rules

  • •Use Hilt as the default DI framework for Android projects.
  • •Annotate Application class with @HiltAndroidApp.
  • •Annotate all Activities and Fragments that use injection with @AndroidEntryPoint.
  • •Scope dependencies correctly — @Singleton for app-wide, @ViewModelScoped for ViewModel lifetime.
  • •Never inject Activity or Fragment context into @Singleton-scoped objects — use @ApplicationContext.
  • •Define bindings in @Module classes — use @Binds for interface-to-implementation, @Provides for construction.
  • •Use @Qualifier annotations to distinguish same-type bindings — not named strings.
  • •Keep modules focused — one module per feature boundary.
  • •Use constructor injection over field injection wherever possible.
  • •Never use Dagger directly when Hilt is available — Hilt reduces boilerplate.

Core Patterns

  • •@InstallIn(SingletonComponent::class) for app-wide singletons.
  • •@InstallIn(ViewModelComponent::class) for ViewModel-scoped dependencies.
  • •Use @AssistedInject for WorkManager Workers and other assisted construction.
  • •Define interface in feature-api, implementation binding in feature-impl module.
  • •Use @EntryPoint for injecting into classes Hilt doesn't manage (ContentProvider, etc.).
  • •Wrap third-party SDK initialization in @Provides methods for testability.

References

  • •references/hilt_setup.md
  • •references/scoping.md
  • •references/multi_module_di.md
  • •references/testing_di.md
  • •references/common_mistakes.md
  • •references/advanced_patterns.md