Why it is not possible to use ViewPager within a Fragment? It actually is

Question

There are information that it is impossible to use ViewPager within a Fragment in many sources like "The Busy Coders Guide for Android Developers" by Mark Murphy, or posts like this on SO. I'm confused because I don't have such a problem and I successfully use ViewPager within my Fragment. The only distinction is that I instantiate a ViewPager not in onCreateView() method but in onActivityCreated(). And everything works perfectly fine.

So the question is - may be I just don't know something and this is not recommended for some reason to make UI instantiations in onActivityCreated()? But again - everything works just fine.

Here is the listing of the class and xml:

Class:

public class ViewPagerFragment extends Fragment {      static final int NUM_ITEMS = 2;      private ViewPagerAdapter mAdapter;     private ViewPager mPager;      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {         return inflater.inflate(R.layout.view_pager_fragment, container, false);     }      @Override     public void onActivityCreated(Bundle savedInstanceState) {         super.onActivityCreated(savedInstanceState);          mAdapter = new ViewPagerAdapter(getFragmentManager());          mPager = (ViewPager) getView().findViewById(R.id.pager);         mPager.setAdapter(mAdapter);     }      public static class ViewPagerAdapter extends FragmentPagerAdapter {         public ViewPagerAdapter(FragmentManager fm) {             super(fm);         }          @Override         public Fragment getItem(int num) {             if (num == 0) {                 return new ItemsListFragment();             } else {                 return new FavsListFragment();             }         }          @Override         public int getCount() {             return NUM_ITEMS;         }     } } 

Layout:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"               android:layout_width="fill_parent"               android:layout_height="fill_parent"               android:orientation="vertical">      <android.support.v4.view.ViewPager         android:id="@+id/pager"         android:layout_width="fill_parent"         android:layout_height="0dp"         android:layout_weight="1"/>  </LinearLayout> 

Answer 1

To implement the View pager within a fragment use getChildFragmentManager() instead of getFragmentManager(). You can call setAdapter() for the ViewPager from onCreateView() or onViewCreated(), that is not a matter.

I hope this will help you guys.