Databinding TextView no data when use apply function to assign lifeCycleOwner - data-binding

Question

The TextView cannot display my data which fetch from network. I am sure that I assign the lifecycleOwner and viewModel in onCreateView but nothing displayed. Then I remove apply function and assign lifecycleOwner line by line and it works but I don't know why. Please tell me if anyone know the reason!
In ViewModel, I have a data class for display
private val _priceData = MutableLiveData<PriceData>()
val priceData: LiveData<PriceData>
get() = _priceData
In Fragment, I assigned the lifecycleOwner and viewModel in onCreateView
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// The TextView display nothing using apply
binding = FragmentPriceBinding.inflate(inflater, container, false).apply{
lifecycleOwner = viewLifecycleOwner
viewModel = viewModel
}
// The TextView show the data correctly if I assign lifeCycle line by line
binding = FragmentPriceBinding.inflate(inflater, container, false)
binding.lifecycleOwner = viewLifecycleOwner
binding.viewModel = viewModel
return binding.root
}
Then I use dataBinding in xml TextView to observe liveData
<data>
<variable
name="viewModel"
type="com.yuyu.gasprice.price.PriceViewModel" />
</data>
<TextView
android:id="#+id/gasoline_change"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center"
android:text="#{viewModel.priceData.predict}" />

Answer 1

You assign your binding.viewModel by binding.getViewModel() . I think you want to assign the viewModel which init from fragment right?
You should replace
viewModel = viewModel
with
viewModel = this#YourFragment.viewModel