Let's look at the official example:
private var _binding: ResultProfileBinding? = null
// This property is only valid between onCreateView and
// onDestroyView.
private val binding get() = _binding!!
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
_binding = ResultProfileBinding.inflate(inflater, container, false)
val view = binding.root
return view
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
Why are there 2 similar variables: _binding and binding? Why can't we use one variable?
This is to have a non-nullable view of the binding property for convenience in the rest of the code, but still have the possibility to manage the actual nullable value in onCreateView/onDestroyView via _binding.
The lateinit approach in activities is nicer, but with lateinit you can't "reset" the binding back to null, so it's not applicable for fragments.