如何从 viewpager 片段中正确地为操作栏膨胀菜单

Question

I have my viewpager as follows:

val pagerAdapter = ViewPagerAdapter()
viewPager2.apply { offscreenPageLimit = 2; adapter = pagerAdapter }
override fun createFragment(position: Int): Fragment = list[position].fragment

So all fragments are inflated from the start.

But I don't know how or where to inflate the menu for my action bar from each fragment. Because if I inflate it like this:

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

        binding = FragmentGenericBinding.inflate(inflater, container, false)

        setHasOptionsMenu(true)

        return bind.root
    }

override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        inflater.inflate(R.menu.menu_add, menu)
        super.onCreateOptionsMenu(menu, inflater)
    }

    override fun onOptionsItemSelected(item: MenuItem): Boolean {
        when (item.itemId) {
            R.id.menu_add -> FragmentAddMenu().show(parentFragmentManager, "Add Menu")
        }
        return super.onOptionsItemSelected(item)
    }

override fun onResume() {
        super.onResume()
        (requireActivity() as AppCompatActivity).supportActionBar?.title = "Menú"
    }

The actionbar menu and title in the first tablayout snippet is from the last inflated fragment.

If I switch between fragments they inflate correctly. But it only happens at the start of the application with the first fragment.

I would like to be able to inflate each menu once the fragment is r,esumed but I couldn't find any examples on the internet or any way around the problem. And if I don't clean the menu on each inflation, the buttons accumulate.

The actionar is a toolbar in the layout of the main activity, it would be easier if each fragment had a toolbar and not added to the main activity. But it looks bad to change fragment with everything and toolbar.

Answer 1

I just move

setHasOptiondMenu(true)

To onResume method