可以使用@AssistedInject和@Assisted注解来实现将一个ViewModel注入到另一个ViewModel中。
例如,假设我们有一个MainViewModel和一个DetailViewModel。我们希望在DetailViewModel中使用MainViewModel,我们可以通过以下步骤实现:
@AssistedFactory interface MainViewModelFactory { fun create(state: SavedStateHandle): MainViewModel }
class MainViewModel @AssistedInject constructor( @Assisted private val state: SavedStateHandle, private val repository: MainRepository ) : ViewModel() { // ... }
class DetailViewModel @AssistedInject constructor( @Assisted private val state: SavedStateHandle, private val mainViewModel: MainViewModel ) : ViewModel() { // ... }
@AssistedFactory interface DetailViewModelFactory { fun create(state: SavedStateHandle, mainViewModel: MainViewModel): DetailViewModel }
@AndroidEntryPoint class MainActivity : AppCompatActivity() {
@Inject
lateinit var mainViewModelFactory: MainViewModelFactory
@Inject
lateinit var detailViewModelFactory: DetailViewModelFactory
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val mainViewModel = ViewModelProvider(this, mainViewModelFactory.create(savedStateHandle)).get(MainViewModel::class.java)
val detailViewModel = ViewModelProvider(
this,
detailViewModelFactory.create(
savedStateHandle,
mainViewModel
)
).get(DetailViewModel::class.java)
// ...
}
}