从微调器中选择保存项目的位置

Question

I want to store the spinner position. This allows me to restore the spinner when the application is opened.

Currently, my code isn't working. It's saving the data, but when I open the application, the last item I clicked does not open.

     @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    refRoomsNew.addValueEventListener(new ValueEventListener() {
                    @Override
                    public void onDataChange(@NonNull DataSnapshot dataSnapshot) {


         for (DataSnapshot snapshot : dataSnapshot.getChildren()){
                    spinner = (Spinner)findViewById(R.id.spinnerMain);
 ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_spinner_item, RoomsNew);
                            dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
               spinner.setAdapter(dataAdapter);


      String data = snapshot.getValue(String.class);
                            RoomsNew.add(data);
                            addListenerOnSpinnerItemSelection();

                            Integer spinnerNew = prefs.getInt("Spinner", 0);

                            // Log.d("Spinner", spinnerNew);
                            if(spinnerNew != null ) {
                                Log.d("spinnerNew", String.valueOf(spinnerNew));
                                spinner.setSelection(spinnerNew);
                            }

                        }
                    }
    }
    @Override
    public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {


        SharedPreferences.Editor editor = getSharedPreferences(MyPREFERENCES, MODE_PRIVATE).edit();
        editor.putInt("Spinner", indexValue);
        editor.apply();
    }

Answer 1

You have to set the position right after setting the adater. Something like:

spiner.setAdater();
SharedPreferences prefs = getSharedPreferences("...",Context.MODE_PRIVATE);
// If "Spinner" is not set, it will assign 0
Integer initialValue = prefs.getInt("Spinner", 0);
spinner.setSelection(initialValue);

Then, during onItemSelected , you just need to store the value:

@Override
public void onItemSelected(AdapterView<?> parent, View v, int position, long id) {
    SharedPreferences.Editor editor = getSharedPreferences(MyPREFERENCES, MODE_PRIVATE).edit();
    editor.putInt("Spinner", position);
    editor.apply();
}