Handling back button in Android Navigation Component

Question

I\'d like to know how properly handle system back button action using Navigation Controller. In my app I have two fragments (for ex. fragment1 and fragment2) and I have an a

Answer 1

you can provide your custom back navigation by using OnBackPressedDispatcher

class MyFragment : Fragment() {

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

    // This callback will only be called when MyFragment is at least Started.
    val callback = requireActivity().onBackPressedDispatcher.addCallback(this) {
        // Handle the back button event
// and if you want to need navigate up
//NavHostFragment.findNavController(this).navigateUp()
    }

    // The callback can be enabled or disabled here or in the lambda
}
}

More explanations in android official guide: https://developer.android.com/guide/navigation/navigation-custom-back