2 Refreshing Issues within a ListFragment

I have two issues with my ListFragment: I want to refresh the the ListFragment once I click a button which I define in the XML File.I initially load the Data of the DataAdapter within a AsyncTask in the TitlesFragment.

I have not found a way to create the code for the button which could access the AsyncTask - and refresh my TitlesFragment

On a different note: The Listfragment updates itself everytime I change the orientation of the phone, which is absolute not the desired behaviour.

public class ClosestPlaces extends FragmentActivity {

private static KantinenListe kantinen;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    requestWindowFeature(Window.FEATURE_ACTION_BAR);        
    setContentView(R.layout.kantinen_results);

}   

/**
 * This is the "top-level" fragment, showing a list of items that the
 * user can pick.  Upon picking an item, it takes care of displaying the
 * data to the user as appropriate based on the currrent UI layout.
 */

public static class TitlesFragment extends ListFragment {
    boolean mDualPane;
    int mCurCheckPosition = 0;


    private class BuildKantinen extends AsyncTask<String, Integer, KantinenListe>   {

        private KantinenListe kantinen;


        @Override
        protected KantinenListe doInBackground(String... params) {
            try{

                Gson gson = new Gson();             
                // SOAP Test
                String NAMESPACE = "http://tempuri.org/";
                String METHOD_NAME = "fullSyncGPS";
                String SOAP_ACTION = "htt开发者_运维百科p://tempuri.org/IDatenService/fullSyncGPS";
                String URL = "http://webserviceURL?wsdl";

                SoapObject request = new SoapObject(NAMESPACE,METHOD_NAME);

                PropertyInfo pi = new PropertyInfo();
                request.addProperty("radius",10);
                request.addProperty("lat", "14.089201");
                request.addProperty("lng", "02.136459");
                request.addProperty("von", "01.09.2011");
                request.addProperty("bis", "01.09.2011");

                SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
                envelope.dotNet = true;
                envelope.setOutputSoapObject(request);        

                HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
                androidHttpTransport.call(SOAP_ACTION, envelope);
                SoapPrimitive result = (SoapPrimitive)envelope.getResponse();

                String resultData = result.toString(); 


                resultData = "{\"meineKantinen\":"+resultData+"}";
                this.kantinen = gson.fromJson(resultData, KantinenListe.class);
                Log.i("test", "blubber" );
            }
            catch(Exception e)
            {
                 e.printStackTrace();
            }
                return this.kantinen;

        }

        @Override
        protected void onPostExecute(KantinenListe result) {
            // populate the List with the data
            Log.i("test", "postexecute" );
            setListAdapter( new MenuAdapter(getActivity(), R.layout.simple_list_item_checkable_1, kantinen.getMeineKantinen()));
        }
    }


    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        new BuildKantinen().execute("test");                       

        if (savedInstanceState != null) {
            // Restore last state for checked position.
            mCurCheckPosition = savedInstanceState.getInt("curChoice", 0);
        }
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        outState.putInt("curChoice", mCurCheckPosition);
    }

    @Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        showDetails(position);            
    }

    /**
     * Helper function to show the details of a selected item, either by
     * displaying a fragment in-place in the current UI, or starting a
     * whole new activity in which it is displayed.
     */
    void showDetails(int index) {
        mCurCheckPosition = index;

            // Otherwise we need to launch a new activity to display
            // the dialog fragment with selected text.
            Log.i("Test",Integer.toString(index));
            Intent intent = new Intent();
            intent.setClass(getActivity(), BeAPartner.class);
            startActivity(intent);
    }
}

public static class MenuAdapter extends ArrayAdapter {

    private LayoutInflater mInflater;
    private List<Kantine> items;
    private Context context;

    public MenuAdapter(Context context, int textViewResourceId, List<Kantine> items) {
        super(context, textViewResourceId);
        mInflater = LayoutInflater.from(context);
        this.items = items;
        this.context = context;
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            convertView = mInflater.inflate(R.layout.menu_row, parent, false);
            holder = new ViewHolder();
            holder.color = (TextView) convertView.findViewById(R.id.color);
            holder.title = (TextView) convertView.findViewById(R.id.detail);
            holder.subdetail = (TextView) convertView.findViewById(R.id.subdetail);

            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        // Fill in the actual story info
        Kantine s = items.get(position);

        s.setName( Html.fromHtml(s.getName()).toString() );
        if (s.getName().length() > 35)
            holder.title.setText(s.getName().substring(0, 32) + "...");
        else
            holder.title.setText(s.getName());

        Log.i("display", "Here I am");
        return convertView;
    }


 }
    static class ViewHolder {
        TextView color;
        TextView title;
        TextView subdetail;
    }   

---

Well to stop the activity from being restarted you can just set android:configChanges attribute on the activity that is running the fragment.

    android:configChanges="orientation"

Setting that tells the system to not restart the activity on an orientation change just to change the orientation.

As for the button, set your click listener in XML by using the attribute android:onClick="myFunction". Then in your fragment define this function:

    public void myFunction(View v)
    {
             new myAsync.execute('test');       
    }

---

When you change the phone orientation, it restarts the activity. Anything you need to be persistent you'll need to save in onSaveInstanceState(Bundle savedInstanceState) and restore with onRestoreInstanceState(Bundle savedInstanceState).

As far as updating the data when clicking a button, try calling notifyDataSetChanged() on the adapter. If that doesn't work, you'll likely just have to run your asynctask again.

---

Ok, I thought it's best practice to post a possible solution in a new answer - for the obvious reasons of readability:

public void reload(View v)
{
    if (getSupportFragmentManager().findFragmentById(R.id.titles) != null) { 
            Fragment titles = (ListFragment)getSupportFragmentManager().findFragmentById(R.id.titles);
            //recreate the fragment
            titles.onActivityCreated(null);
    }
}

Does exactly what I want ( reload the data )! However ... I think the memory footprint of this solution might be bad.