我的 ViewModelFactory:
class ViewModelFactory @Inject constructor(
private val viewModelMap: MutableMap<Class<out ViewModel>, ViewModelAssistedFactory<out ViewModel>>,
owner: SavedStateRegistryOwner,
defaultArgs: Bundle?
) : AbstractSavedStateViewModelFactory(owner, defaultArgs) {
@Throws(IllegalStateException::class)
@Suppress("UNCHECKED_CAST")
override fun <T : ViewModel?> create(key: String, modelClass: Class<T>, handle: SavedStateHandle): T {
return viewModelMap[modelClass]?.create(handle) as? T ?: throw IllegalStateException("Unknown ViewModel class")
}
}
活动:
@Inject
lateinit var viewModelFactory: ViewModelFactory
protected val viewModel: ViewModel by lazy { ViewModelProvider(this, viewModelFactory).get(getViewModelClass()) }
查看模型:
@AssistedInject.Factory
interface Factory : ViewModelAssistedFactory<SplashViewModel>
我想知道如何动态提供defaultArgs,而不是。
ActivityModule
@Module
companion object {
@JvmStatic
@Nullable
@Provides
fun provideDefaultArgs(): Bundle? {
return null
}
}
我们的想法是有可能向ViewModel发送一个参数,比如说一个DetailActivity的ID。StateHandle map
会更好。类似于... 这个 和 这个.
有意义吗?可以吗?
我遇到了2个解决方案。
方案一:
把我们的ViewModelFactory改成:
class ViewModelFactory @Inject constructor(
private val viewModelMap: MutableMap<Class<out ViewModel>, ViewModelAssistedFactory<out ViewModel>>
) {
fun create(owner: SavedStateRegistryOwner, defaultArgs: Bundle? = null): AbstractSavedStateViewModelFactory {
return object : AbstractSavedStateViewModelFactory(owner, defaultArgs) {
@Suppress("UNCHECKED_CAST")
override fun <T : ViewModel?> create(key: String, modelClass: Class<T>, handle: SavedStateHandle): T {
return viewModelMap[modelClass]?.create(handle) as? T ?: throw IllegalStateException("Unknown ViewModel class")
}
}
}
}
最后:
@Inject
lateinit var viewModelFactory: ViewModelFactory
protected val viewModel: ViewModel by lazy { ViewModelProvider(this, viewModelFactory.create(this, args).get(getViewModelClass()) }
另外,我们可以将ActivityModule简化为(例子)。
@AssistedModule
@Module(includes = [AssistedInject_SplashActivityModule::class])
abstract class SplashActivityModule{
@Binds
@IntoMap
@ViewModelKey(SplashViewModel::class)
abstract fun bindFactory(factory: SplashViewModel.Factory): ViewModelAssistedFactory<out ViewModel>
}
这个 职位 由 Tomáš Mlynarič 帮忙解决了这个问题。
解决方案B。
创建一个 Factory
没有注入的依赖关系。
class ViewModelFactoryAlt<out V : ViewModel>(
private val viewModelFactory: ViewModelAssistedFactory<V>,
owner: SavedStateRegistryOwner,
defaultArgs: Bundle? = null
) : AbstractSavedStateViewModelFactory(owner, defaultArgs) {
@Suppress("UNCHECKED_CAST")
override fun <T : ViewModel> create(key: String, modelClass: Class<T>, handle: SavedStateHandle): T {
return viewModelFactory.create(handle) as T
}
}
创建我们的 ViewModelAssitedFactory
喜欢。
class HelloWorldViewModelFactory @Inject constructor(
private val dependencyA: DependencyA,
...
) : ViewModelAssistedFactory<HelloWorldViewModel> {
override fun create(stateHandle: SavedStateHandle): HelloWorldViewModel {
return HelloWorldViewModel(stateHandle, dependencyA, ...)
}
}
最后:
@Inject
lateinit var factory: HelloWorldViewModelFactory
private val viewModel: HelloWorldViewModel by viewModels { ViewModelFactoryAlt(factory, this, intent.extras) }
这个... 岗位 由 Elye 帮忙解决了这个问题。