setUserVisibleHint with Fragments for android -

im using 3 fragments in viewpager adapter. loading data parse(parse.com) , displaying them in recycler views. following code causing app crash. understanding when mainactivity loads, first fragment ie, gets viewed user setuservisiblehint function gets called , in v.findviewbyid code causes null pointer exception since setcontentview hasnt/ may not been called. proof if add 1sec delay setuservisisblehint code works properly.

now want add server pull requests using parse, add data in list adapter , populate recyclerview after user views page so

1) should add code in setuservisisblehint , add 0.5secc delay gets executed after setcontentview called ensuring dont null pointer exception error or

2) there better way/ other functions can use achieve same?

public class newsfeed extends fragment {         linearlayoutmanager mlayoutmanager;         boolean _arelecturesloaded=false;         view v;         progressbar bar;          public newsfeed() {             // required empty public constructor         }          @override         public view oncreateview(layoutinflater inflater, @nullable viewgroup container,                                  @nullable bundle savedinstancestate) {             // inflate layout fragment             v=inflater.inflate(r.layout.fragment_news_feed, container, false);              recyclerview mrecyclerview = (recyclerview)v.findviewbyid(r.id.recycler_view);             mrecyclerview.sethasfixedsize(true);             mlayoutmanager = new linearlayoutmanager(v.getcontext());             mrecyclerview.setlayoutmanager(mlayoutmanager);                 mystickyadapter madapter = new mystickyadapter(v.getcontext());                 mrecyclerview.setadapter(madapter);            // mrecyclerview.additemdecoration(new stickyrecyclerheadersdecoration(madapter));             return v;         }          @override         public void setuservisiblehint(boolean isvisibletouser) {             super.setuservisiblehint(isvisibletouser);             if (isvisibletouser && !_arelecturesloaded ) {                 _arelecturesloaded = true;                 v.findviewbyid(r.id.asd).setvisibility(view.gone);             }         }       }//closes fragment 

im using library recycler view stickyheaderrecyclerview

i highly recommend avoiding adding delays if you're running on main thread. avoid npe, try moving findviewbyid(r.id.asd) oncreateview method after inflate view:

@override     public view oncreateview(layoutinflater inflater, @nullable viewgroup container,                              @nullable bundle savedinstancestate) {         // inflate layout fragment         v=inflater.inflate(r.layout.fragment_news_feed, container, false);         v.findviewbyid(r.id.asd).setvisibility(view.gone); 

this assuming r.id.asd in r.layout.fragment_news_feed

this post provide insight: setuservisiblehint called before oncreateview in fragment