@Override protected void onPostExecute(final Object o) { // argument could be null if (o != null) { // NavigationView navigationView = // (NavigationView)((AppCompatActivity)context).findViewById(R.id.navigation_view); RecyclerView recyclerView = (RecyclerView) ((AppCompatActivity) context).findViewById(R.id.listView); if (recyclerView != null) { recyclerView.setLayoutManager(new LinearLayoutManager(context)); MemberListAdapter memberListAdapter = new MemberListAdapter(context, (List<Member>) o); recyclerView.setAdapter(memberListAdapter); final StickyRecyclerHeadersDecoration headersDecoration = new StickyRecyclerHeadersDecoration(memberListAdapter); recyclerView.addItemDecoration(headersDecoration); memberListAdapter.registerAdapterDataObserver( new RecyclerView.AdapterDataObserver() { @Override public void onChanged() { headersDecoration.invalidateHeaders(); } }); // ((SwipeRefreshLayout)((AppCompatActivity)context) // .findViewById(R.id.frag_group_members_swipe_refresh)) // .setRefreshing(false); } } }