onCreate，onResume＆amp; onPause在旋转时保存recyclerView位置？

Question

无论我选择遵循stackoverflow中的哪个示例，我都无法获得所需的结果。

我想在旋转时保存recyclelerView滚动位置，但选择(TOP RATED MOVIES, FAVORITE MOVIES AND POPULAR MOVIES )状态的保存似乎覆盖了重新加载所需选择的状态，但是从屏幕顶部开始。

E.g。在它的底部的一半或全部，然后，旋转它保存选择类型（例如它在旋转前显示的任何内容）但是从头开始加载（顶部（这是不希望的，我需要留在相同的位置））。

我的代码：

MainActivity

public class MainActivity extends AppCompatActivity {


    public static final String TAG = MainActivity.class.getSimpleName();
    public static final int POP = 1;
    public static final int TOP = 2;
    public static final int FAV = 3;
    int selection = -1;
    private RecyclerView rv;
    private MovieAdapter adapter;
    private MovieDbHelper dbHelper;
    private FrameLayout frame;
    private AppCompatActivity activity = MainActivity.this;
    private static final String BUNDLE_RECYCLER_LAYOUT = "classname.recycler.layout";
    public static int index = -1;
    public static int top = -1;
    int currentVisiblePosition;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        if (!isOnline()) {
            Toast.makeText(activity, "No Connection", Toast.LENGTH_SHORT).show();
        } else {

            initControls();
            dbHelper = new MovieDbHelper(activity);
            if (savedInstanceState != null) {
                selection = savedInstanceState.getInt("selection");
                //Now just load the list
                switch (selection) {
                    case POP:
                        loadJSON(POP);
                        break;
                    case TOP:
                        loadJSON(TOP);
                        break;
                    case FAV:
                        initializeFavorites();
                        break;
                    case -1:
                        initializeViews();
                        break;
                }
            } else {
                initializeViews();
            }
        }

    }




    private void initControls() {
        rv = findViewById(R.id.rv_main);
        adapter = new MovieAdapter(this, new ArrayList<Movie>());

        rv.setLayoutManager(new GridLayoutManager(this, ScreenSizeUtil.calculateNoOfColumns(this)));


        rv.setItemAnimator(new DefaultItemAnimator());
        rv.setAdapter(adapter);



        dbHelper = new MovieDbHelper(activity);

        frame = findViewById(R.id.frame);

        checkSortOrder();
    }

    private void initializeViews() {

        Toast.makeText(this, "Change sort order via the Settings Menu....", Toast.LENGTH_SHORT).show();
    }

    private void initializeFavorites() {


        getAllFavorites();

    }
    private boolean isOnline() {
        ConnectivityManager cm =
                (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();
        return netInfo != null && netInfo.isConnectedOrConnecting();
    }




    private void loadJSON(int listType) {

        try {
            if (BuildConfig.THE_MOVIE_DB_API_TOKEN.isEmpty()) {
                Toast.makeText(this, "Error with Api Key....", Toast.LENGTH_SHORT).show();

                return;
            }
            Client Client = new Client();
            Service apiService =
                    Client.getClient().create(Service.class);

            Call<MovieResponse> call = listType==TOP? apiService
                    .getMovies("top_rated",BuildConfig.THE_MOVIE_DB_API_TOKEN): apiService.getMovies("popular",BuildConfig.THE_MOVIE_DB_API_TOKEN) ;
            call.enqueue(new Callback<MovieResponse>() {
                @Override
                public void onResponse(Call<MovieResponse> call, final Response<MovieResponse> response) {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            List<Movie> movies = response.body().getResults();
                            adapter.setMovieList(movies);
                            rv.scrollToPosition(0);


                        }
                    });


                }

                @Override
                public void onFailure(Call<MovieResponse> call, Throwable t) {

                    Log.d("Error", t.getMessage());
                    Toast.makeText(MainActivity.this, "Error with Data!", Toast.LENGTH_SHORT).show();
                }
            });
        } catch (Exception e) {
            Log.d("Error", e.getMessage());
            Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
        }


    }



    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putParcelable(BUNDLE_RECYCLER_LAYOUT, rv.getLayoutManager().onSaveInstanceState());
    }

    private void checkSortOrder(){
        SharedPreferences preferences = PreferenceManager.getDefaultSharedPreferences(this);
        String sortOrder = preferences.getString(
                this.getString(R.string.pref_sort_order_key),
                this.getString(R.string.pref_most_popular)
        );
        if (sortOrder.equals(this.getString(R.string.pref_most_popular))) {
            Log.d(TAG, "Sorting by most popular");
            loadJSON(POP);
        } else if (sortOrder.equals(this.getString(R.string.pref_highest_rated))){
            Log.d(TAG, "Sorting by Top rated");
            loadJSON(TOP);
        } else{
            Log.d(TAG, "Sorting by Favorites");
            initializeFavorites();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu, menu);

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        int id = item.getItemId();


        if (id == R.id.action_settings) {
            Intent intent = new Intent(this, SettingsActivity.class);
            startActivity(intent);
            return true;
        }
        return super.onOptionsItemSelected(item);

    }

    @Override
    protected void onResume() {
        super.onResume();
        (rv.getLayoutManager()).scrollToPosition(currentVisiblePosition);
        currentVisiblePosition = 0;
    }

    @Override
    public void onPause() {
        super.onPause();
        currentVisiblePosition = 0;
        currentVisiblePosition = ((LinearLayoutManager)rv.getLayoutManager()).findFirstCompletelyVisibleItemPosition();}

    private void getAllFavorites() {
        new AsyncTask<Void, Void, ArrayList<Movie>>() {
            @Override
            protected ArrayList<Movie> doInBackground(Void... voids) {
                return new ArrayList<>(dbHelper.getAllFavorites());
            }

            @Override
            protected void onPostExecute(ArrayList<Movie> aVoid) {
                super.onPostExecute(aVoid);
                adapter.setMovieList(aVoid);
            }
        }.execute();
    }



}

任何建议都会很棒，请注意与How to save scroll position of RecyclerView in Android?的细微差别。

由于 本