Hilt报错：ActivityContext无法提供，求适配CredentialManager的Activity Context

问题场景 #

我按如下方式配置Hilt模块：

@Module
@InstallIn(ActivityRetainedComponent::class)
object CredentialModule {

    @Provides
    @ActivityRetainedScoped
    fun provideActivityContext(
        @ActivityContext context: Context
    ) = context

    @Provides
    @ActivityRetainedScoped
    fun provideFirebaseAuth(): FirebaseAuth = FirebaseAuth.getInstance()

    @Provides
    @ActivityRetainedScoped
    fun provideCredentialManager(
        context: Context
    ): CredentialManager = CredentialManager.create(context)

    @Provides
    @ActivityRetainedScoped
    fun provideGetGoogleIdOption(
        context: Context
    ): GetGoogleIdOption = GetGoogleIdOption.Builder()
        .setFilterByAuthorizedAccounts(false)
        .setServerClientId(context.getString(R.string.web_client_id))
        .setAutoSelectEnabled(false)
        .build()

    @Provides
    @ActivityRetainedScoped
    fun provideGetCredentialRequest(
        getGoogleIdOption: GetGoogleIdOption
    ) = GetCredentialRequest.Builder()
        .addCredentialOption(getGoogleIdOption)
        .build()

    @Provides
    @ActivityRetainedScoped
    fun provideAuthDataSource(
        context: Context,
        auth: FirebaseAuth,
        credentialManager: CredentialManager,
        getCredentialRequest: GetCredentialRequest
    ) = AuthDataSource(context, auth, credentialManager, getCredentialRequest)

} 

但始终抛出如下错误：

error: [Dagger/MissingBinding] @dagger.hilt.android.qualifiers.ActivityContext android.content.Context cannot be provided without an @Provides-annotated method.
  public abstract static class SingletonC implements ProfileApp_GeneratedInjector,
                         ^
  
      @dagger.hilt.android.qualifiers.ActivityContext android.content.Context is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityRetainedC] com.being.coder.app.profile.di.CredentialModule.provideActivityContext(context)
      android.content.Context is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityRetainedC] com.being.coder.app.profile.di.CredentialModule.provideAuthDataSource(context, �)
      com.being.coder.app.profile.data.datasource.AuthDataSource is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityRetainedC] com.being.coder.app.profile.di.CredentialModule.provideAuthRepository(authDataSource)
      com.being.coder.app.profile.presentation.signin.repository.AuthRepository is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityRetainedC] com.being.coder.app.profile.di.CredentialModule.provideAuthUseCases(authRepository)
      com.being.coder.app.profile.domain.usecase.auth.AuthUseCases is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ViewModelC] com.being.coder.app.profile.ui.screens.auth.AuthViewModel(authUseCases)
      com.being.coder.app.profile.ui.screens.auth.AuthViewModel is injected at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ViewModelC] com.being.coder.app.profile.ui.screens.auth.AuthViewModel_HiltModules.BindsModule.binds(arg0)
      @dagger.hilt.android.internal.lifecycle.HiltViewModelMap java.util.Map<java.lang.Class<?>,javax.inject.Provider<androidx.lifecycle.ViewModel>> is requested at
          [com.being.coder.app.profile.ProfileApp_HiltComponents.ViewModelC] dagger.hilt.android.internal.lifecycle.HiltViewModelFactory.ViewModelFactoriesEntryPoint.getHiltViewModelMap() [com.being.coder.app.profile.ProfileApp_HiltComponents.SingletonC ? com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityRetainedC ? com.being.coder.app.profile.ProfileApp_HiltComponents.ViewModelC]
  
  Note: @dagger.hilt.android.qualifiers.ActivityContext android.content.Context is provided in the following other components:
      [com.being.coder.app.profile.ProfileApp_HiltComponents.ActivityC] dagger.hilt.android.internal.modules.ActivityModule.provideContext(�)

我曾尝试使用@ApplicationContext解决问题，但CredentialManager.create(context)需要Activity Context，请问如何在当前场景下获取Activity Context以消除报错？

解决方案 #

核心原因 #

ActivityRetainedComponent的生命周期跨Activity配置变更（比如屏幕旋转），它不依赖具体的Activity实例，因此Hilt不会在这个组件中提供@ActivityContext的依赖——Activity Context仅在ActivityComponent及其子组件中可用。

具体实现步骤 #

1. 拆分模块，分离Activity级依赖
   将需要Activity Context的提供者（如CredentialManager、GetGoogleIdOption）移到安装在ActivityComponent的模块中：

   @Module
   @InstallIn(ActivityComponent::class)
   object ActivityAuthModule {
   
       @Provides
       @ActivityScoped
       fun provideCredentialManager(
           @ActivityContext context: Context
       ): CredentialManager = CredentialManager.create(context)
   
       @Provides
       @ActivityScoped
       fun provideGetGoogleIdOption(
           @ActivityContext context: Context
       ): GetGoogleIdOption = GetGoogleIdOption.Builder()
           .setFilterByAuthorizedAccounts(false)
           .setServerClientId(context.getString(R.string.web_client_id))
           .setAutoSelectEnabled(false)
           .build()
   
       @Provides
       @ActivityScoped
       fun provideGetCredentialRequest(
           getGoogleIdOption: GetGoogleIdOption
       ) = GetCredentialRequest.Builder()
           .addCredentialOption(getGoogleIdOption)
           .build()
   }
   

2. 调整ActivityRetained模块的依赖注入方式
   保留跨配置保留的依赖（如FirebaseAuth、AuthDataSource）在原模块中，但通过Provider延迟获取Activity级别的依赖，避免生命周期不匹配导致的内存泄漏：

   @Module
   @InstallIn(ActivityRetainedComponent::class)
   object CredentialModule {
   
       @Provides
       @ActivityRetainedScoped
       fun provideFirebaseAuth(): FirebaseAuth = FirebaseAuth.getInstance()
   
       @Provides
       @ActivityRetainedScoped
       fun provideAuthDataSource(
           @ApplicationContext context: Context,
           auth: FirebaseAuth,
           credentialManager: Provider<CredentialManager>,
           getCredentialRequest: Provider<GetCredentialRequest>
       ) = AuthDataSource(context, auth, credentialManager.get(), getCredentialRequest.get())
   }
   

关键说明 #

• 使用Provider<T>可以让ActivityRetainedScoped的对象在需要时才获取Activity级别的实例，确保此时Activity仍然存活，避免持有已销毁的Activity引用。
• 如果AuthDataSource中不会立即使用CredentialManager，建议在具体调用方法时再调用Provider.get()，进一步降低内存泄漏风险。

内容的提问来源于stack exchange，提问作者Arshad Ali