无法将类型强制转换为“ ListViewModel”，因为“ binding.listViewModel”是一个可变的属性，此时可能已更改

我正在用Kotlin为Android做一个小任务工。我将主要活动分为几个片段，然后为每个片段创建一个ViewModel。但是现在这里出现了智能投放的问题。

这是一些代码：

class ListFragment : Fragment() {

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?): View? {

        val binding: FragmentListBinding = DataBindingUtil.inflate(
            inflater, R.layout.fragment_list, container, false)

        val application = requireNotNull(this.activity).application

        val dataSource = TaskDatabase.getInstance(application).taskDatabaseDao

        val viewModelFactory = ListViewModelFactory(dataSource, application)

        val listViewModel =
            ViewModelProviders.of(this, viewModelFactory).get(ListViewModel::class.java)

        binding.listViewModel = listViewModel

        binding.setLifecycleOwner(this)

        binding.addButton.setOnClickListener {
            findNavController().navigate(R.id.action_listFragment_to_createTaskFragment)
        }

        binding.listViewModel.tasks.observe(this, Observer {
            it?.forEach {
                Log.i("ListFragment", "tasks exist")
                val radioButton = RadioButton(context)
                radioButton.text = it.title
                radioButton.visibility = View.VISIBLE
                radioButton.setOnClickListener {
                    Toast.makeText(context, "Working", Toast.LENGTH_SHORT).show()
                }
            }
        })

        return binding.root
    }
}

class ListViewModel(
    val database: TaskDao,
    application: Application) : AndroidViewModel(application) {

    private val viewModelJob = Job()

    private val uiScope = CoroutineScope(Dispatchers.Main + viewModelJob)

    private val _tasks = MutableLiveData<List<Task>>()
    val tasks: LiveData<List<Task>>
        get() = _tasks

    init {
        initializeTasks()
    }

    private fun initializeTasks() {
        uiScope.launch {
            _tasks.value = getTasksFromDatabase()?.value
            Log.i("ListViewModel", "something")
        }
    }

    private suspend fun getTasksFromDatabase(): LiveData<List<Task>>? {
        return withContext(Dispatchers.IO) {
            database.getAllTasks()
        }
    }

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

我本来希望在观察者方法的帮助下在主屏幕上看到一些创建的radioButtons，但是我得到了一个例外，该问题的标题中提到了此例外。预先感谢您的帮助！