android - BaseClass 中的 Kotlin 泛型。试图通过 BaseFragment 中的泛型类型获取 ViewModel

Question

嘿，我想创建通过泛型类型获取 viewModel 的 BaseFragment 类:

abstract class BaseFragment<B : ViewDataBinding, VM : ViewModel> : DaggerFragment() {

    val viewModel by viewModels<VM> { viewModelFactory }
    ...
}

// Native function
@MainThread
inline fun <reified VM : ViewModel> Fragment.viewModels(
    noinline ownerProducer: () -> ViewModelStoreOwner = { this },
    noinline factoryProducer: (() -> Factory)? = null
) = createViewModelLazy(VM::class, { ownerProducer().viewModelStore }, factoryProducer)

但出现错误 Cannot use 'VM' as reified type parameter. Use a class instead.是否有可能实现我想要做的事情？也许用其他方法？

Answer 1

找到了工作方式，但它足够干净吗？

abstract class BaseModelFragment<VM : ViewModel>(viewModelClass: KClass<VM>) : DaggerFragment() {

    @Inject
    lateinit var viewModelFactory: ViewModelProvider.Factory

    val viewModel by viewModel(viewModelClass) { viewModelFactory }

    private fun Fragment.viewModel(
        clazz: KClass<VM>,
        ownerProducer: () -> ViewModelStoreOwner = { this },
        factoryProducer: (() -> ViewModelProvider.Factory)? = null,
    ) = createViewModelLazy(clazz, { ownerProducer().viewModelStore }, factoryProducer)
}

和用法:

open class SomeFragment : BaseModelFragment<CustomerSupportViewModel>(CustomerSupportViewModel::class) {
...
}

它已经过测试并且可以正常工作。任何想法如何改进它？ :)