Aqui eu tenho umtoolbar em umActivity que contém umSearchView. E essa atividade tem vários fragmentos. Um fragmento principal deles tem mais 10 fragmentos dentro de si. Todos os 10 fragmentos estão mostrando dados em visualizações de lista. Agora estou tentando filtrar todas as listas de fragmentos porSearchView doMainActivity. Mas nunca filtra a lista de cada fragmento. Agora eu mostro como eu implementei tudo.

MainActivity.java

public class MainActivity extends AppCompatActivity {
 @Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.menu_main, menu);
    final SearchView searchView = (SearchView) MenuItemCompat.getActionView(menu.findItem(R.id.action_search));
    SearchManager searchManager = (SearchManager) getSystemService(SEARCH_SERVICE);
    searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
    changeSearchViewTextColor(searchView);
    return true;
}
}

Fragment.java

public class CurrencyFragment2 extends android.support.v4.app.Fragment implements SearchView.OnQueryTextListener {

    @Override
public void setMenuVisibility(boolean menuVisible) {
    super.setMenuV,isibility(menuVisible);
    if (menuVisible && getActivity() != null) {
        SharedPreferences pref = getActivity().getPreferences(0);
        int id = pref.getInt("viewpager_id", 0);
        if (id == 2)
            setHasOptionsMenu(true);
 }
 }
    @Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
    inflater.inflate(R.menu.main, menu); // removed to not double the menu items
    MenuItem item = menu.findItem(R.id.action_search);
    SearchView sv = new SearchView(((MainActivity) getActivity()).getSupportActionBar().getThemedContext());
    changeSearchViewTextColor(sv);
    MenuItemCompat.setShowAsAction(item, MenuItemCompat.SHOW_AS_ACTION_COLLAPSE_ACTION_VIEW | MenuItemCompat.SHOW_AS_ACTION_IF_ROOM);
    MenuItemCompat.setActionView(item, sv);
    sv.setOnQueryTextListener(this);
    sv.setIconifiedByDefault(false);
    super.onCreateOptionsMenu(menu, inflater);
}

private void changeSearchViewTextColor(View view) {
    if (view != null) {
        if (view instanceof TextView) {
            ((TextView) view).setTextColor(Color.WHITE);
            ((TextView) view).setHintTextColor(Color.WHITE);
            ((TextView) view).setCursorVisible(true);
            return;
        } else if (view instanceof ViewGroup) {
            ViewGroup viewGroup = (ViewGroup) view;
            for (int i = 0; i < viewGroup.getChildCount(); i++) {
                changeSearchViewTextColor(viewGroup.getChildAt(i));
            }
        }
    }
}

@Override
public boolean onQueryTextSubmit(String query) {
    return true;
}

@Override
public boolean onQueryTextChange(String newText) {
    if (adapter != null) {
        adapter.filter2(newText);
    }
    return true;
}

Método de filtro dentro da classe Adapter.

// Filter Class
public void filter2(String charText) {
    charText = charText.toLowerCase(Locale.getDefault());
    items.clear();
    if (charText.length() == 0) {
        items.addAll(arraylist);
    } else {
        for (EquityDetails wp : arraylist) {
            if (wp.getExpert_title().toLowerCase(Locale.getDefault()).contains(charText)) {
                items.add(wp);
            }
        }
    }
    notifyDataSetChanged();
}