Question

First to say that I looked everywhere and I cannot find a solution, but I’m sorry if I repeat something.
So this is a situation, I have an android application that is parsing data from some xml url and shows it in listview. Also there is a spinner filled with some items, so i want to filter that retrived data from xml with variable selected from spinner and than add to listview. I created setOnItemSelectedListener and when i choose something from spinner I get toast message of that value, but I can’t use it later. This is the code:

public class profesorActivity extends ListActivity {
    // All static variables
    static final String URL = "http://cvele.net78.net/obavestenja1.xml";
    // XML node keys
    static final String KEY_OBAV = "obavestenja"; // parent node
    static final String KEY_PROF = "profesor";
    static final String KEY_PRE = "predmet";
    static final String KEY_TXT = "tekst";
    static final String KEY_VRE = "vreme";
    Spinner spin;
    ArrayAdapter<String> aa;
    String[] items = { "item1","item2", "item3", "item4", "item5", "item6","item7"};

    ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();

    XMLParser parser = new XMLParser();
    String xml = parser.getXmlFromUrl(URL); // getting XML
    Document doc = parser.getDomElement(xml); // getting DOM element
    Object string1;

    NodeList nl = doc.getElementsByTagName(KEY_OBAV);

    public void onCreate(Bundle savedInstanceState) {
        getWindow().requestFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.profesor);

        spin=(Spinner)findViewById(R.id.spinner);
        aa = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,items);
        aa.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        spin.setAdapter(aa);
        spin.setOnItemSelectedListener(new OnItemSelectedListener(){
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id){
                string1=spin.getSelectedItem().toString();
                Toast.makeText(getBaseContext(), "Selected:" + string1.toString(),Toast.LENGTH_LONG ).show();
            }
            public void onNothingSelected(AdapterView<?> parent) {
                Toast.makeText(getBaseContext(), "Spinner1: unselected",Toast.LENGTH_LONG ).show();
            }
        });

        NodeList nl = doc.getElementsByTagName(KEY_OBAV);
        // looping through all item nodes <item>
        for (int i = 0; i < nl.getLength(); i++) {
            // creating new HashMap
            HashMap<String, String> map = new HashMap<String, String>();

            Element e = (Element) nl.item(i);

            // adding each child node to HashMap key => value
            map.put(KEY_PROF, parser.getValue(e,KEY_PROF));
            map.put(KEY_PRE, parser.getValue(e, KEY_PRE));
            map.put(KEY_TXT, parser.getValue(e, KEY_TXT));
            map.put(KEY_VRE, parser.getValue(e, KEY_VRE));

            if((parser.getValue(e, KEY_PROF)).equals(string1.toString()))
                menuItems.add(map);
            else
                Toast.makeText(getBaseContext(), "nothing", Toast.LENGTH_LONG).show();

        }
        // Adding menuItems to ListView
        ListAdapter adapter = new SimpleAdapter(this, menuItems,R.layout.list_item, new String[] { KEY_PROF, KEY_PRE, KEY_TXT, KEY_VRE }, new int[] {R.id.profesor,R.id.predmet, R.id.tekst, R.id.vreme});
        setListAdapter(adapter);

To be more precise, when I select something from spinner I want that in variable string1,
than is shown, as I sad before, as a toast(Toast.makeText(getBaseContext(), "Selected:" + string1.toString(),Toast.LENGTH_LONG ).show();) every time I select something from spinner it is shown, but down in that for loop string1 is useless, i cannot use it to compare to that variable if((parser.getValue(e, KEY_PROF)).equals(string1.toString())), but when I compare, for example, to a word if((parser.getValue(e, KEY_PROF)).equals("test")) it works, and also it works with firs default value in spinner. So changing the selected value doesn’t change the state of variable string1, outside of listener. I tried many other way to save spinner selected item as string, but no luck. What I am doing wrong, I hope I described well problem, if I’m not please ask, I broke my head of thinking and searching the web. Thank you in ahead.

Answer 1

When the onCreate() method runs, it executes all of the code. This means that the class member “Object string1” has not been set because the spinner event hasen’t fired yet. You may want to look at the Android Activity life cycle so that you initialize and call methods at the appropriate time.

The key is that once the spinner event “onItemSelected” is handled that you not only update

string1=spin.getSelectedItem().toString();

but also update the list and call notify for the change.