java - Disappearing data from RecyclerView -

i made app fragment containing viewpager. inside viewpager displaying list using recyclerview. when launch app great. when swipe few tabs , coming list isn't shown. don't know wrong...

fragment displayed inside viewpager

public class gradesfragmentpage extends fragment {     view view;     list<grade> gradelist;      @override     public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {         return inflater.inflate(r.layout.grades_page_fragment, container, false);     }      @override     public void onactivitycreated(bundle savedinstancestate) {         super.onactivitycreated(savedinstancestate);          betterrecyclerview betterrecyclerview = (betterrecyclerview) getactivity().findviewbyid(r.id.gradesrecycler);         betterrecyclerview.setlayoutmanager(new linearlayoutmanager(getactivity()));     }      @override     public void onviewcreated(view view, bundle savedinstancestate) {         this.view = view;          if(getarguments() != null) {             gradelist = getarguments().getparcelablearraylist("grades");              betterrecyclerview betterrecyclerview = (betterrecyclerview) view.findviewbyid(r.id.gradesrecycler);             betterrecyclerview.setadapter(new gradesadapter(getactivity(), gradelist));         }     } } 

betterrecyclerview

public class betterrecyclerview extends recyclerview {     public betterrecyclerview(context context) {         super(context);     }      public betterrecyclerview(context context, attributeset attrs) {         super(context,attrs);          setlayoutmanager(new layoutmanager() {             @override             public layoutparams generatedefaultlayoutparams() {                 return null;             }         });     }      public betterrecyclerview(context context, attributeset attrs, int defstyle) {         super(context, attrs, defstyle);     }      //we need protected method scroll detection     public int getverticalscrolloffset() {         return computeverticalscrolloffset();     } } 

viewpager has method setoffscreenpagelimit allows specify number of pages kept adapter. fragments far away destroyed.

first of looking @ code don't see doing memory releasing measures in fragments ondestroy(). fact fragment destroyed , gc'ed not mean resources allocated removed too.

viewpager.setoffscreenpagelimit(10);