ViewPager fragments disappear when change screen rotation

Question

I'm working on android application that contains ViewPager with Fragments, like this:

MainActivity(MainActivityFragment(screenSlideViewPager(Fragments))), which means:

Activity contains Fragment contains ViewPager contains Fragments

Now my problem is when rotate device or change screen rotation all Fragments in ViewPager are disappear.

any ideas to solve this issue?

EDIT 1

MainActivity.java:

@Override protected void onCreate(Bundle savedInstanceState) {     super.onCreate(savedInstanceState);      if (getSupportFragmentManager().findFragmentByTag(TAG) == null) {         final FragmentTransaction ft = getSupportFragmentManager()                 .beginTransaction();         ft.add(android.R.id.content, new MainActivityFragment(), TAG);         ft.commit();     } } 

MainActivityFragment.java:

public class MainActivityFragment extends Fragment {     private ViewPager mPager = null;     private PagerAdapter mPageAdapter = null;      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {         final View reVal = inflater.inflate(R.layout.activity_main, container, false);         mPager = (ViewPager) reVal.findViewById(R.id.pagerMainContent);         mPageAdapter = new ScreenSlidePagerAdapter(getActivity().getFragmentManager());         mPager.setAdapter(mPageAdapter);         return reVal;     }      private MainGridViewFragment mainGridFragment;     private AlphabetGridViewFragment alphabetGridFragment;      private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {         public ScreenSlidePagerAdapter(FragmentManager fm) {             super(fm);         }          @Override         public android.app.Fragment getItem(int position) {             switch (position) {                 case 1:                     mainGridFragment = new MainGridViewFragment();                     return mainGridFragment;                 case 0:                     alphabetGridFragment = new AlphabetGridViewFragment();                     return alphabetGridFragment;                 default:                     return null;             }         }          @Override         public int getCount() {             return 2;         }     } } 

EDIT 2

Obviously MainActivity and MainActivityFragment are loaded, and the proof is The ActionBar, notice also that ViewPager is loaded too, because you still can navigate between pages (the blue light means that the pager reached to last page) but you can't see its content.

Answer 1

It looks like your main activity is using the getSupportFragmentManager() while your fragment is using getFragmentManager().

Not sure if this is worthy of an answer post but my rating is too low to reply any other way. :)

Edit: I believe you may also need to extend a FragmentActivity with the support library.

See: https://stackoverflow.com/a/10609839/2640693

Edit 2:

public class MainActivityFragment extends FragmentActivity {     private ViewPager mPager = null;     private PagerAdapter mPageAdapter = null;      @Override     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {         final View reVal = inflater.inflate(R.layout.activity_main, container, false);         mPager = (ViewPager) reVal.findViewById(R.id.pagerMainContent);         mPageAdapter = new ScreenSlidePagerAdapter(getChildFragmentManager());         mPager.setAdapter(mPageAdapter);         return reVal;     }      private MainGridViewFragment mainGridFragment;     private AlphabetGridViewFragment alphabetGridFragment;      private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter {         public ScreenSlidePagerAdapter(FragmentManager fm) {             super(fm);         }          @Override         public Fragment getItem(int position) {             switch (position) {                 case 1:                     mainGridFragment = new MainGridViewFragment();                     return (Fragment)mainGridFragment;                 case 0:                     alphabetGridFragment = new AlphabetGridViewFragment();                     return (Fragment)alphabetGridFragment;                 default:                     return null;             }         }          @Override         public int getCount() {             return 2;         }     } } 

Answer 2

I tried many solution but get success in any one. At last I fixed as below:

• Use getActivity().getSupportFragmentManager() rather than getChildFragmentManager()

• Override getItemId(int position) method in your ViewPagerAdapter class like below:

  @Override public long getItemId(int position) {     return System.currentTimeMillis(); } 

For me it's working like charm, please also comment here your view.