retain state of viewpager fragments android

I have a viewpager in a fragment in which i am showing 3 fragments but when I open the fragment first time it opens fine and when I move to another fragment and came back to the viewpager fragment it doesn't show the fragments in view pager then I have to either change the orientation of the phone or keep swiping the viewpager for the hidden fragments to show. I have googled it and now I know I have to set the tag to each fragment and retrieve fragment with findfragmentbytag method but problem is when I try to set the tag to fragment ``` getSupportFragmentManager().beginTransaction().add(myFragment, "Some Tag").commit(); ``` above line crashes my app and logcat shows "cant set tag to fragment", I know I'm doing some stupid mistake this is the complete code of my fragment. I would really appreciate if one could guide me where to write the code for setting the tag of fragments. thanks in advance. ``` public class MatchesListingFragment extends Fragment implements ActionBar.TabListener { Context context; SectionsPagerAdapter mSectionsPagerAdapter; ViewPager mViewPager; ActionBar actionBar; Matchlistings db; Bundle savedInstanceState; Fragment livescore,fixture,results; @Override public void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); this.savedInstanceState = savedInstanceState; db = new Matchlistings(getActivity()); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.fragment_matches, container, false); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); context = getActivity().getApplicationContext(); if(savedInstanceState == null){ livescore = new LiveScoreListingFragment(); fixture = new FixturesListingFragment(); results = new ResultsListingFragment(); } if(!Constants.is_listing_refreshed){ Log.i(MainActivity.TAG,"refreshing list"); db.loadListingsFromServer().executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR); } actionBar = getActivity().getActionBar(); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); if(mSectionsPagerAdapter == null) mSectionsPagerAdapter = new SectionsPagerAdapter(getActivity().getSupportFragmentManager()); mViewPager = (ViewPager) getView().findViewById(R.id.pager); mViewPager.setAdapter(mSectionsPagerAdapter); mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { actionBar.setSelectedNavigationItem(position); } }); for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) { Tab tb = actionBar.newTab() .setText(mSectionsPagerAdapter.getPageTitle(i)) .setTabListener(this); actionBar.addTab(tb); } } public class SectionsPagerAdapter extends FragmentPagerAdapter { Fragment fragment; public SectionsPagerAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { switch(position){ case 0: fragment = livescore; return fragment; case 1: fragment = fixture; return fragment; case 2: fragment = results; return fragment; case 3: fragment = new LiveScoreListingFragment(); return fragment; } return null; } @Override public int getCount() { return 4; } @Override public CharSequence getPageTitle(int position) { switch (position) { case 0: return "LIVE"; case 1: return "FIXTURES"; case 2: return "RESULTS"; case 3: return "HOT"; } return null; } } @Override public void onDestroy() { // TODO Auto-generated method stub super.onDestroy(); actionBar.removeAllTabs(); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD); } @Override public void onTabReselected(Tab arg0, FragmentTransaction arg1) { // TODO Auto-generated method stub } @Override public void onTabSelected(Tab arg0, FragmentTransaction arg1) { // TODO Auto-generated method stub } @Override public void onTabUnselected(Tab arg0, FragmentTransaction arg1) { // TODO Auto-generated method stub } } ``` EDIT: i have now tried to get the fragment from viewpager by tag instead of creating new fragment everytime. but problem is still same. ``` FixturesListingFragment fixture = (FixturesListingFragment) getActivity().getSupportFragmentManager().findFragmentByTag("android:switcher:"+R.id.pager+":1"); if(fixture == null) fixture = new FixturesListingFragment(); ```