how to change other spinner based on the spinner selected before?

Question

i'm trying to change my second spinner based on what i choose in the first spinner without using any json or database. it must be change the spinner below depend on what we choose in the first spinner. i'm trying with the code below but is doesn't work

this is the java code

    Spinner gedungSpn, lantaiSpn, ruangSpn;

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

        if (gedungSpn.getSelectedItemPosition() == 0){
            LantaiSpinnerRektorat();
        }else if(gedungSpn.getSelectedItemPosition() == 1){
            LantaiSpinnerGL();
        }
    }
 public void GedungSpinner(){

        gedungSpn = (Spinner) findViewById(R.id.gedung_spn);
        List<String> list = new ArrayList<String>();
        list.add("Rektorat");
        list.add("Griya Legita");
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        gedungSpn.setAdapter(dataAdapter);
    }

    public void LantaiSpinnerRektorat(){

        lantaiSpn = (Spinner) findViewById(R.id.lantai_spn);
        List<String> list = new ArrayList<String>();
        list.add("Lantai 1");
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        lantaiSpn.setAdapter(dataAdapter);
    }

    public void LantaiSpinnerGL(){

        lantaiSpn = (Spinner) findViewById(R.id.lantai_spn);
        List<String> list = new ArrayList<String>();
        list.add("Lantai 1");
        list.add("Lantai 2");
        list.add("Lantai 3");
        list.add("Lantai 4");
        list.add("Lantai 5");
        list.add("Lantai 6");
        list.add("Lantai 7");
        list.add("Lantai 8");
        ArrayAdapter<String> dataAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_dropdown_item, list);
        dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        lantaiSpn.setAdapter(dataAdapter);
    }

please help me. maybe some trick could help. i'm also trying that change the adapter on if statement but it still doesnt work at all

Answer 1

Replace

        if (gedungSpn.getSelectedItemPosition() == 0){
            LantaiSpinnerRektorat();
        }else if(gedungSpn.getSelectedItemPosition() == 1){
            LantaiSpinnerGL();
        }

with

gedungSpn.setOnItemSelectedListener(new OnItemSelectedListener() {

            @Override
            public void onItemSelected(AdapterView<?> adapterView, View view,
                    int position, long id) {
                if (position == 0){
                   LantaiSpinnerRektorat();
                 }else if(position == 1){
                   LantaiSpinnerGL();
                 }
            }

            @Override
            public void onNothingSelected(AdapterView<?> adapterView) {
                // TODO Auto-generated method stub

            }
        });