I have implemented some fragments which are hosted by a single Activity (they're in the same activity). In one of these fragments (Let's say fragment A), I have a vertical recyclerview.
The problem is arises when I want to navigate from Fragment A to other fragments (Again, in the same activity). Suppose that I'm clicking the middle member of the list, then I navigate to the next fragment. When I want to back into the first fragment (Fragment A), it inflates the list from first. Seeming that it looses its position, however, using onSaveInstanceState() and also onCreateView(), I try to store and restore the selected item's position every time I quit or enter the fragment.
I think this issue may be originated from fragments' lifecycle which all are in one single activity. As this answer, mentioning :
In a Fragment, all of their lifecycle callbacks are directly tied to their parent Activity. So onSaveInstanceState gets called on the Fragment when its parent Activity has onSaveInstanceState called.
and that's why I emphasize on the "single" activity. How can we handle such situation?
I have debugged my program and onSaveInstanceState and onCreateView were not even called when they were supposed to. Below is my attempted code:
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState!=null){
selectedItem = savedInstanceState.getInt(BUNDLE_KEY_SELECTED_ITEM);
}
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if (savedInstanceState != null){
selectedItem = savedInstanceState.getInt(BUNDLE_KEY_SELECTED_ITEM);
}
myRecyclerView = (RecyclerView) v.findViewById(R.id.rv_mine);
// mData is a an ArrayList
myAdapter = new MyAdapter(mData, getContext(), this.selectedItem);
myLayoutManager = new LinearLayoutManager(getActivity());
myRecyclerView.setLayoutManager(myLayoutManager);
myRecyclerView.setAdapter(myAdapter);
return v;
}
@Override
public void onSaveInstanceState(Bundle outState) {
outState.putInt(BUNDLE_KEY_SELECTED_ITEM,selectedItem);
super.onSaveInstanceState(outState);
}
