Options menu inflate wrongly in viewpager2

Question

I have 4 fragments but for each fragments it has different different menu options in my app with viewpager2 so the user swipe through these all fragments and when the app starts the menu option for the first fragment showing the wrong which is 4th fragment menu option item that wrongly inflated in 1st fragment whenever I open the app it only occur when I open the app freshly but when I swipe to 2nd fragment and come back to first then it work correctly but at start/opening the app firstly then it shows wrong menu item btw I using setOffScreenPageLimit(4) this problem occurs when I use this method I hope anyone could solve this problem

I guess this is my situation I tried this ->

How to correctly inflate menus for an action bar from viewpager fragments

but it shouldn't work

Answer 1

I am giving you here full source code for your problem. Give it a try and hope it might help you. Create an options menu according to your requirement.

Follow below steps

1 - activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/viewPager"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

2 - MainActivity.java

public class ViewPagerActivity extends AppCompatActivity {

@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.viewpager_activity);

    initViewPager();
}

private void initViewPager() {
    ViewPager2 viewPager = findViewById(R.id.viewPager);
    ViewpagerAdapter adapter = new ViewpagerAdapter(this);
    viewPager.setAdapter(adapter);

    // Add menu items without overriding methods in the Activity
    addMenuProvider(new MenuProvider() {
        @Override
        public void onCreateMenu(@NonNull Menu menu, @NonNull MenuInflater menuInflater) {
            // Add menu items here
            switch (viewPager.getCurrentItem()) {
                case 0:
                    getMenuInflater().inflate(R.menu.menu_one, menu);
                    break;

                case 1:
                    getMenuInflater().inflate(R.menu.menu_two, menu);
                    break;

                case 2:
                    getMenuInflater().inflate(R.menu.menu_three, menu);
                    break;

                case 3:
                    getMenuInflater().inflate(R.menu.menu_four, menu);
                    break;
            }
        }

        @Override
        public boolean onMenuItemSelected(@NonNull MenuItem menuItem) {
            return false;
        }
    });
}

}

3 - Your viewpager2 adapter

public class ViewpagerAdapter extends FragmentStateAdapter {

    public ViewpagerAdapter(@NonNull FragmentActivity fragmentActivity) {
        super(fragmentActivity);
    }

    @NonNull
    @Override
    public Fragment createFragment(int position) {
        return MyFragment.newInstance(position);
    }

    @Override
    public int getItemCount() {
        return 4;
    }
}

4 - Your fragment

public class MyFragment extends Fragment {

    private int fragmentPos = 0;

    public MyFragment(int fragmentPos) {
        this.fragmentPos = fragmentPos;
    }

    public static MyFragment newInstance(int fragmentPos) {
        Bundle args = new Bundle();
        MyFragment fragment = new MyFragment(fragmentPos);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_view, container, false);
    }

    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        setHasOptionsMenu(true);
        AppCompatTextView label = view.findViewById(R.id.tvFragPos);
        label.setText("Current fragment index \n" + fragmentPos);
    }
}

Output