Scene cannot be cast to android.content.ComponentCallbacks

在使用依赖注入框架 Koin 注入 ViewModel 时报 ClassCastException 异常，是否应该为 Scene 继承 ComponentCallbacks 接口https://github.com/bytedance/scene/blob/3dc15e1f2e5ce0acc662c65613475ee386341a24/library/scene/src/main/java/com/bytedance/scene/Scene.java#L112

[emredagci]

If you would like to use two frameworks together, you should define a new extension then you can use the koin framework with scene framework.

import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentActivity
import androidx.lifecycle.*
import com.bytedance.scene.Scene
import org.koin.android.viewmodel.*
import org.koin.core.Koin
import org.koin.core.context.GlobalContext
import org.koin.core.parameter.ParametersDefinition
import org.koin.core.qualifier.Qualifier
import org.koin.core.scope.Scope
import kotlin.reflect.KClass

inline fun <reified T : ViewModel> LifecycleOwner.customViewModel(
    qualifier: Qualifier? = null,
    noinline parameters: ParametersDefinition? = null
): Lazy<T> = lazy { getViewModelCustom(qualifier, parameters) }

inline fun <reified T : ViewModel> LifecycleOwner.getViewModelCustom(
    qualifier: Qualifier? = null,
    noinline parameters: ParametersDefinition? = null
): T {
    return getViewModelCustom(T::class, qualifier, parameters)
}

fun <T : ViewModel> LifecycleOwner.getViewModelCustom(
    clazz: KClass<T>,
    qualifier: Qualifier? = null,
    parameters: ParametersDefinition? = null
): T {
    return GlobalContext.get().koin.getViewModelCustom(
        ViewModelParameters(
            clazz,
            this@getViewModelCustom,
            qualifier,
            parameters = parameters
        )
    )
}

fun <T : ViewModel> Koin.getViewModelCustom(parameters: ViewModelParameters<T>): T {
    val vmStore: ViewModelStore = parameters.owner.getViewModelStoreCustom(parameters)
    val viewModelProvider = rootScope.createViewModelProviderCustom(vmStore, parameters)
    return viewModelProvider.getInstanceCustom(parameters)
}

fun <T : ViewModel> ViewModelProvider.getInstanceCustom(parameters: ViewModelParameters<T>): T {
    val javaClass = parameters.clazz.java
    return if (parameters.qualifier != null) {
        this.get(parameters.qualifier.toString(), javaClass)
    } else {
        this.get(javaClass)
    }
}

fun <T : ViewModel> LifecycleOwner.getViewModelStoreCustom(
    parameters: ViewModelParameters<T>
): ViewModelStore =
    when {
        parameters.from != null -> parameters.from!!.invoke().viewModelStore
        this is FragmentActivity -> ViewModelStores.of(this)
        this is Fragment -> ViewModelStores.of(this)
        this is Scene -> this.viewModelStore
        else -> error("Can't getByClass ViewModel '${parameters.clazz}' on $this - Is not a FragmentActivity nor a Fragment neither a valid ViewModelStoreOwner")
    }

fun <T : ViewModel> Scope.createViewModelProviderCustom(
    vmStore: ViewModelStore,
    parameters: ViewModelParameters<T>
): ViewModelProvider {
    return ViewModelProvider(
        vmStore,
        object : ViewModelProvider.Factory {
            override fun <T : ViewModel> create(modelClass: Class<T>): T {
                return get(parameters.clazz, parameters.qualifier, parameters.parameters)
            }
        })
}

After you created the extension you can use like code shown below.

class SplashScene : Scene() {

    private val splashViewModel: SplashViewModel by customViewModel()

}

[Ccixyj]

另外一种是自己写一个LifecycleOwner.getKoin()的扩展方法。然后通过getkoin().getViewModel(lifecycleowner…)手动实现一个viewmodl代理方法。

fun LifecycleOwner.getKoin(): Koin = when (this) {
    is KoinComponent -> this.getKoin()
    is Scene -> ((this as? KoinComponent)?.getKoin()
        ?: (this.requireActivity() as? KoinComponent)?.getKoin()
        ?: error("scene attach parent must be KoinComponent"))
    else -> KoinContextHandler.get()
}