android新手,在用observe的时候遇到这个问题,这里需要实现lifecycleOwner接口的类,androidx.fragment.app.Fragment不是就是实现了这个借口嘛?为什么还会报这个错误呢?求解答
class PlaceFragment : Fragment() {
val viewModel by lazy { ViewModelProviders.of(this).get(PlaceViewModel::class.java) }
private lateinit var adapter: PlaceAdapter
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_place, container, false)
}
override fun onActivityCreated(savedInstanceState: Bundle?) {
super.onActivityCreated(savedInstanceState)
val layoutManager = LinearLayoutManager(activity)
recyclerView.layoutManager = layoutManager
adapter = PlaceAdapter(this, viewModel.placeList)
recyclerView.adapter = adapter
searchPlaceEdit.addTextChangedListener { editable ->
val content = editable.toString()
if (content.isNotEmpty()) {
viewModel.searchPlaces(content)
} else {
recyclerView.visibility = View.GONE
bgImageView.visibility = View.VISIBLE
viewModel.placeList.clear()
adapter.notifyDataSetChanged()
}
}
viewModel.placeLiveData.observe(this, Observer{ result ->
val places = result.getOrNull()
if (places != null) {
recyclerView.visibility = View.VISIBLE
bgImageView.visibility = View.GONE
viewModel.placeList.clear()
viewModel.placeList.addAll(places)
adapter.notifyDataSetChanged()
} else {
Toast.makeText(activity, "未能查询到任何地点", Toast.LENGTH_SHORT).show()
result.exceptionOrNull()?.printStackTrace()
}
})
}
}