我在Kotlin
中实现了MVP架构,Android Studio没有显示错误,但是无法编译:
是否可以在继承过程中使用ConcreteView
/ ConcretePresenter
?
码:
/**
* These are the base classes
*/
interface MvpView
interface BaseView<Presenter : BasePresenter<*>> : MvpView, HasMvpView<MvpView>
// to avoid circular dependency
interface HasMvpView<View : MvpView>
abstract class BaseMvpActivity<Presenter : BasePresenter<*>> : AppCompatActivity(), HasMvpView<MvpView>
abstract class BaseMvpFragment<Activity : BaseMvpActivity<*>, Presenter : BasePresenter<*>>: Fragment(), HasMvpView<MvpView> {
// this will cause the error
abstract var presenter: Presenter
}
/**
* There's a Viewpager, and each page looks the same the only difference is their source of data. That's why I tried implementing another level of abstraction over the base classes
*/
interface CategoryPagerView<Presenter: BasePresenter<*>> : BaseView<Presenter>
abstract class CategoryPagerFragment: BaseMvpFragment<LandingActivity, BasePresenter<*>>()
/**
* A concrete type of the Viewpager's fragment, its presenter and the view
*/
interface ConcreteView : CategoryPagerView<ConcretePresenter>
class ConcretePresenter(view: ConcreteView) : BasePresenter<*>(view)
class ConcreteFragment : CategoryPagerFragment(), ConcreteView {
// this line shows no error in the IDE, but in compile time
override var presenter = ConcretePresenter(this)
谢谢你的帮助!
最佳答案
这是编译器抛出的内部声明错误。您可以在此处看到编译器源代码:
https://github.com/JetBrains/kotlin/blob/master/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/model/ResolvedCallImpl.java
显然,resultingDescriptor
在不应该成为null
的位置是null
。因此,这似乎是一个编译器错误。也许应该用Kotlin重写它,以避免null
出现问题:)
请在https://youtrack.jetbrains.com/issues/KT提交错误报告