Question

即使我使用数据视图模型，但recyclerview仍会在每次屏幕方向更改时一直滚动到顶部。

   override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    (activity as AppCompatActivity).setSupportActionBar(binding?.toolbar)


    val host: NavHostFragment = activity?.supportFragmentManager
        ?.findFragmentById(R.id.nav_host_fragment) as NavHostFragment?
        ?: return

    // Set up Action Bar
    val navController = host.navController

    // Setup bottom navigation view
    binding?.bottomNav?.setupWithNavController(navController)

}


override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
     binding = DataBindingUtil.inflate(inflater , com.angelstudio.newsapp.R.layout.fragment_feed,container , false)
    myView= binding.root

    return myView
}

override fun onActivityCreated(savedInstanceState: Bundle?) {
    super.onActivityCreated(savedInstanceState)
    viewModel =ViewModelProviders.of(this,viewModelFactory).get(FeedFragmentViewModel::class.java)

    bindUi()
    (activity as? AppCompatActivity)?.supportActionBar?.title = getString(R.string.Naws_App)
    (activity as? AppCompatActivity)?.supportActionBar?.subtitle = getString(R.string.Feed)

    binding.mySwiperefresh.setOnRefreshListener {
        refresh()
        mySwiperefresh.setRefreshing(false)
    }
}


 private fun bindUi()=launch {
    val topHeadline =viewModel.topHeadline.await()
    val naviagte =viewModel.navigateToDetail.await()

    topHeadline.observe(this@FeedFragment, Observer {
        if(it == null || it.isEmpty()) return@Observer

      binding.recyclerView.apply {
            showShimmerAdapter()
            topHeadlineAdapter = TopHeadlineAdapter(TopHeadlineListener { 
                url ->  viewModel.onTopHeadlineClicked(url)
            })
            adapter = topHeadlineAdapter
            topHeadlineAdapter.submitList(it)
            hideShimmerAdapter()
        }
    })

这是我在片段上的代码，我找不到我在做错什么，是否有一些东西可以处理viewmodel上的recyclerview位置状态？

Answer 1

将android:configChanges="orientation|keyboardHidden"添加到manifest中的活动标签中，如下所示：

<activity
        android:name=".activity.MainActivity"
        android:configChanges="orientation|keyboardHidden"
        android:theme="@style/AppTheme.NoActionBar">

</activity>

Answer 2

Take a look at this stackoverflow link

您需要以已保存的实例状态存储回收站视图的位置，一旦更改了配置，您必须将回收站视图滚动到存储的位置

Recyclerview在屏幕旋转时失去位置

2 个答案: