getArguments（）。getString在我的片段中始终返回null

Question

I have a following problem. I would like to save the values of some TextView s so that they can be retrieved and displayed after reutrning back to this Fragment (I use replace() method to switch Fragment s). I followed the advice from this POST , so my code looks like this right now:

public class NumbersFragment extends Fragment {
    private static final String LONGITUDE_SAVE = "longitudeSave";
    private static final String LATITUDE_SAVE = "latitudeString";

    public TextView tvLatitude;
    public TextView tvLongitude;
    public Button startButton;
    public Button stopButton;

    public NumbersFragment() {
        setArguments(new Bundle());
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.numbers_fragment, container, false);
        tvLatitude = (TextView) rootView.findViewById(R.id.tv_latitude);
        tvLongitude = (TextView) rootView.findViewById(R.id.tv_longitude);
        startButton = (Button) rootView.findViewById(R.id.start_button);
        stopButton = (Button) rootView.findViewById(R.id.stop_button);

        refreshUI();

        startButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getActivity().startService(new Intent(getActivity(), RecordService.class));
            }
        });

        stopButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getActivity().stopService(new Intent(getActivity(), RecordService.class));
            }
        });

        //getActivity().setTitle(R.string.record);
        LocalBroadcastManager.getInstance(getActivity().getApplicationContext()).registerReceiver(
                new BroadcastReceiver() {
                    @Override
                    public void onReceive(Context context, Intent intent) {
                        double latitude = intent.getDoubleExtra(RecordService.EXTRA_LATITUDE, 0);
                        double longitude = intent.getDoubleExtra(RecordService.EXTRA_LONGITUDE, 0);
                        //textView.setText("Lat: " + latitude + ", Lng: " + longitude);
                        //tvLocation.setText("Latitude" + Double.toString(latitude) + "Longitude" + Double.toString(longitude));
                        tvLongitude.setText("Longitude: " + Double.toString(longitude));
                        tvLatitude.setText("Latitude: " + Double.toString(latitude));
                    }
                }, new IntentFilter(RecordService.ACTION_LOCATION_BROADCAST)
        );
        return rootView;
    }

    @Override
    public void onPause() {
        super.onPause();
        String latitudeToSave = tvLatitude.getText().toString();
        String longitudeToSave = tvLongitude.getText().toString();
        getArguments().putString(LATITUDE_SAVE, latitudeToSave);
        getArguments().putString(LONGITUDE_SAVE, longitudeToSave);
        Log.d("onPause", latitudeToSave + " " + longitudeToSave);
    }

    @Override
    public void onResume() {
        super.onResume();
        refreshUI();
    }

    public void refreshUI() {
        Bundle mySavedInstanceState = getArguments();
        String loadedLatitude = mySavedInstanceState.getString(LATITUDE_SAVE);
        String loadedLongitude = mySavedInstanceState.getString(LONGITUDE_SAVE);
        Log.d("refreshUI", loadedLatitude + " " + loadedLongitude);
        tvLatitude.setText(loadedLatitude);
        tvLongitude.setText(loadedLongitude);
    }
}

The problem is that after returning to the Fragment refreshUI method is called, but loadedLatitude and loadedLongitude String s are always null . What am I doing wrong?

Answer 1

Pass Bundle savedInstanceState to refreshUI() method

Correct code : refreshUI(savedInstanceState);

Receive it in method and use it :

refreshUI(Bundle a) { String loadedLatitude = a.getString(LATITUDE_SAVE)

This will work