从 FragmentB 返回后，数据绑定对 FragmentA 不起作用

问：

我的应用程序有两个片段：和 . 将一些连接信息绑定到 UI。信息从广播接收器获取。一开始，数据绑定工作，但当用户转到 然后返回 时，info 不会绑定。HomeFragmentStatusFragmentHomeFragmentHomeFragmentStatusFragmentHomeFragment

HomeFragment、StatusFragment 和 HomeFragmentViewModel 类如下所示：

class HomeFragment : Fragment() {

    private var binding: FragmentHomeBinding? = null
    private var connectionStatus: String? = "Offline"
    private var connectionType: String? = ""

    private lateinit var mReceiver: ConnectivityChangeBroadcastReceiver
    lateinit var homeFragmentViewModel: HomeFragmentViewModel
    lateinit var repo: Repository

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        binding = FragmentHomeBinding.inflate(inflater, container, false)
        binding?.lifecycleOwner = viewLifecycleOwner
        
        repo = Repository().getInstance()!!
        val viewModelFactory = HomeFragmentViewModelFactory(repo)
        homeFragmentViewModel =
            ViewModelProvider(this, viewModelFactory)[HomeFragmentViewModel::class.java]

        binding?.homeFragmentViewModel = homeFragmentViewModel
        this.mReceiver = ConnectivityChangeBroadcastReceiver()

        mReceiver.mData.observe(this, Observer {
            repo.setInfo(mReceiver.getData())
            homeFragmentViewModel.getConnectionInfo()
        })

        homeFragmentViewModel.navToStatusFragment.observe(this, Observer {
            if (it==true){
                this.findNavController().navigate(R.id.action_homeFragment_to_statusFragment)
                homeFragmentViewModel.doneNavigateToStatusFragment()
            }
        })

        return binding?.root
    }


    override fun onStart() {
        super.onStart()

        requireActivity().registerReceiver(
            mReceiver, IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION)
        )
        repo.setInfo(mReceiver.getData())
    }

    override fun onStop() {
        super.onStop()
        requireActivity().unregisterReceiver(mReceiver)
    }

}

class StatusFragment : Fragment() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        requireActivity().onBackPressedDispatcher.addCallback(this){
            requireActivity().supportFragmentManager.popBackStack()
        }
        return inflater.inflate(R.layout.fragment_status, container, false)
    }

}

class HomeFragmentViewModel(private val repo: Repository?) : ViewModel() {

    private val viewModelJob = Job()

    private val _navToStatusFragment = MutableLiveData<Boolean?>()
    val navToStatusFragment: LiveData<Boolean?>
        get() = _navToStatusFragment

    private val _connected = MutableLiveData<String?>()
    val connected: LiveData<String?>
        get() = _connected

    private val _connectionType = MutableLiveData<String?>()
    val connectionType: LiveData<String?>
        get() = _connectionType

    init {
        _navToStatusFragment.value = false
    }

    var isConnected: LiveData<Boolean> = connected.map {
        when (it) {
            "Online" -> true
            else -> false
        }
    }

    fun doneNavigateToStatusFragment(){
        _navToStatusFragment.value = false
    }

    fun navigateToStatusFragment(){
        _navToStatusFragment.value = true
    }

    fun getConnectionInfo() {

        when (repo?.getInfo()?.value) {
            0 -> {
                _connected.value = "Offline"
                _connectionType.value = "Check Your Connection"
                _connectionDetails.value = null
            }
            1 -> {
                _connected.value = "Online"
                _connectionType.value = "Cellular"
                _connectionDetails.value = null
            }
            2 -> {
                _connected.value = "Online"
                _connectionType.value = "WIFI"
                _connectionDetails.value = null
            }
            3 -> {
                _connected.value = "Online"
                _connectionType.value = "VPN"
                _connectionDetails.value = null
            }
        }
        Log.d("LOGGED", "Info Checked ...")
    }


    override fun onCleared() {
        super.onCleared()
        viewModelJob.cancel()
    }
}

我做了：

• 在 中使用 也regiterReceiver()onResume()
• using 代替 forviewLifeCycleOwnerthisbinding.lifeCycleOwner
• 按下后退按钮时使用popBackStack()StatusFragment

更新：问题是回到 HomeFragment 后，调用了 onCreateView（），但未调用 HomeFragmentViewModelFactory（）！->我需要它来发送新的存储库对象到视图模型