The onCreateView() method is not invoked for the fragment containing a recyclerView. Im using a FragmentStatePagerAdapter as the ViewPagerAdapter

Question

I have two fragments.

1) A fragment with just a TextView(OneFragment)

2) A fragment with a recycler view who's contents are being populated in the onCreateView() of the Fragment (Two Fragment)

In the Activity class I use a viewPager to control these fragments!!

However I'm faced with the problem.

The onCreateView() method of the TwoFragment is called when the activity is first loaded! When I go to the other fragments and return back to the Two Fragment the onCreateView() method is not called.

Instead of showing me a recyclerView it renders a blank screen ! However when I change my orientation of the device! The onCreateView() is called and and the list is populated!

I want it to show the TwoFragment while returning back to it.

However the OneFragment has no problems of this ! Any time I return to it, The normal big textView is shown!

Here is the Code for my ViewPager Adapter

    class ViewPagerAdapter extends FragmentStatePagerAdapter {
private final List<Fragment> mFragmentList = new ArrayList<>();
private final List<String> mFragmentTitleList = new ArrayList<>();

public ViewPagerAdapter(FragmentManager manager) {
    super(manager);
}

@Override
public Fragment getItem(int position) {
    return mFragmentList.get(position);
}


@Override
public int getItemPosition(Object object){
   // return PagerAdapter.POSITION_NONE;
    Fragment f = (Fragment) object;
    for(Fragment frag: mFragmentList){
      return frag.getTagInt();
    }
    return FragmentStatePagerAdapter.POSITION_NONE;

}

@Override
public int getCount() {

    return mFragmentList.size();
}

public void addFragment(Fragment fragment, String title) {
    mFragmentList.add(fragment);
    mFragmentTitleList.add(title);

}

public void clearAll(){
    mFragmentList.clear();
    mFragmentTitleList.clear();
    notifyDataSetChanged();
}

@Override
public CharSequence getPageTitle(int position) {
    return mFragmentTitleList.get(position);
}

}

And I set The ViewPager adapter like this :

      private void setupViewPager(ViewPager viewPager,int choice) {
    if(choice == 1){
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.clearAll();
        adapter.addFragment(new OneFragment(), "One");
        adapter.addFragment(new TwoFragment(), "Two");
        viewPager.setAdapter(adapter);

    }
    else{
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.clearAll();
        adapter.addFragment(new OneFragment(), "One");
        adapter.addFragment(new OneFragment(), "Two");
        viewPager.setAdapter(adapter);


    }

}

and here's my previous getItemId()

     @Override
public int getItemPosition(Object object){
   // return PagerAdapter.POSITION_NONE;
    Fragment f = (Fragment) object;
    for(int i=0;i<getCount();i++){
        Fragment fragment = getItem(i);
        if(f.equals(fragment)){
            return i;
        }
    }
    return FragmentStatePagerAdapter.POSITION_NONE;

}

Any kind of help is Much Appreciated ! Cause I'm kinda stuck after going through the web and stackOverflow!!

Answer 1

You should not return POSITION_NONE in getItemPosition () for every request. POSITION_NONE means you're telling the pager adapter that this particular fragment is removed from the list and please modify the pages/fragments accordingly. When you return this, adapter will delete the fragment from its own private list of fragments. This is returned when you want to remove the fragment.

Send the position of the fragment using the indexof method of list interface.

See this post for more info.