RecyclerView在使用喷气背包导航时会导致内存泄漏吗

Question

假设我有这样一个片段。

class MyFragment : Fragment() {
// Suppose there is a binding, which contains a recyclerView
private var _binding: FragmentAbinding? = null
val binding get() = _binding!!

// Suppose there is a recyclerView adapter
val adapter by lazy { MyAdapter() }
// use navigation as router
private val navController: NavController by lazy { findNavController() }
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
_binding = FragmentAbinding.inflate(
inflater,
container,
false
)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
// ...
binding.recyclerView.adapter = adapter
// ...
}
override fun onDestroyView() {
_binding = null
}
}

当使用navController.anavigation(…(时，MyFragment将被替换，绑定为空。但是，由于recyclerView使用观察者模式来观察适配器中的数据集，因此适配器将持有recyclerView作为其观察者。在导航到另一个片段(即onDestroyView((之后(后，recyclerView是否会主动取消对适配器数据集的观察，这意味着适配器不会持有recyclerView的实例？

我使用以下方法删除适配器数据集观察器

fun RecyclerView.Adapter<*>.removeObservers() {
var clazz: Class<*> = javaClass
val simpleName = RecyclerView.Adapter::class.simpleName
while (clazz.simpleName != simpleName) {
clazz = clazz.superclass
}
val field = clazz.getDeclaredField("mObservable")
field.isAccessible = true
val observable = field[this] as Observable<*>
observable.unregisterAll()
}
// in fragment
class MyFragment : Fragment() {
override fun onDestroyView() {
adapter.removeObservers()
}
}

Answer 1

调用时的适配器"onCreateViewHolder"；使用recyclerView作为视图组。当您使用导航进行导航时，您的片段只查看了已销毁的片段，但其实例在后台仍处于活动状态，而您的适配器也处于活动状态。因为这是解决此问题的类级变量，您应该在视图生命周期事件中创建适配器(onViewCreated.onDestroyView(。