How to Refresh ListView in Fragment that is filled with BaseAdapter?

Question

I want to Refresh a ListView in a Fragment when a Dialog is closed. Until now the refresh only works when I restart the app and I don't really know why.

Here are the classes:

This is the Fragment with the ListView on it, that i want to refresh, when the Dialog is closed.

public class RegisterListFragment extends Fragment {


    public static final String TAG = "RegisterListFragment";

    RegisterListAdapter adapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        setRetainInstance(true);
        // TODO Auto-generated method stub

        View view = inflater.inflate(R.layout.act_select_list_fragment, container, false);


        ListView list = (ListView) view.findViewById(R.id.register_list);
        list.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
                                    long arg3) {
                Intent i = new Intent(getActivity(), com.example.smartkasse.Act_Register.MainActivity.class).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                TextView selectedRegisterTextView = (TextView) arg1.findViewById(R.id.title);
                String selectedRegisterName = (String) selectedRegisterTextView.getText();
                i.putExtra("selectedRegisterName", selectedRegisterName);
                startActivity(i);
                getActivity().finish();
            }
        });
        adapter = new RegisterListAdapter(getActivity());
        list.setAdapter(adapter);

        return view;
    }


    public void refreshData() {
        adapter.notifyDataSetChanged();
    }
}

And this is the Adapter I fill the List with:

public class RegisterListAdapter extends BaseAdapter {
    View view = null;

    Database db = new Database(mContext);
    data=db.getAlltitles();
    if(convertView==null)

    {

        view = (View) inflater.inflate(R.layout.act__select_listview, null);

        TextView title = (TextView) view.findViewById(R.id.title);
        TextView artist = (TextView) view.findViewById(R.id.artist);
        TextView duration = (TextView) view.findViewById(R.id.duration);
        ImageView thumb_image = (ImageView) view.findViewById(R.id.list_image);

        title.setText(data.get(position));
        //artist.setText(data.get(position));
        //duration.setText(data.get(position));
        //thumb_image.setImageResource(R.drawable.ic_launcher);

        return view;
    }

    else

    {

        TextView title = (TextView) convertView.findViewById(R.id.title);
        TextView artist = (TextView) convertView.findViewById(R.id.artist);
        TextView duration = (TextView) convertView.findViewById(R.id.duration);
        ImageView thumb_image = (ImageView) convertView.findViewById(R.id.list_image);

        title.setText(data.get(position));
        // artist.setText(data.get(position));
        // duration.setText(data.get(position));
        //thumb_image.setImageResource(R.drawable.ic_launcher);

        return convertView;
    }
}

And this is the Main that holds everything together:

When the positv Button of the Dialog is pressed, then new Data is added to the Database that i want

public class MainActivity extends SherlockFragmentActivity implements OnRegisterCreatedListener {
    RegisterListFragment registerListFragment;
    HelpFragment helpFragment;

    boolean helpVisible = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        // Grund-Layout für die Activity festlegen
        setContentView(R.layout.act_select_main);

        addFragments();

        supportInvalidateOptionsMenu();
        setLargeInLandscape();

    }

// Was passiert wenn der Menüknopf gedrückt wird

    // Inflate the menu; this adds items to the action bar if it is present.
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Zeigt nur die die nicht in Actionbar sind, kann aber eingestellt
        // werden im XML-File

        if (helpVisible) {
            getSupportMenuInflater().inflate(
                    R.menu.act_select_menu_help_visible, menu);

        } else {
            getSupportMenuInflater().inflate(
                    R.menu.act_select_menu_registerlist_visible, menu);
        }

        return true;
    }

    // Was passiert wenn ein Menüpunkt ausgewählt wird
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle item selection
        switch (item.getItemId()) {
            // Das wenn der Knopf das Plus war
            case R.id.menu_help:
                changeFragment();
                // this.supportInvalidateOptionsMenu();
                break;
            case android.R.id.home:
                changeFragment();
                // this.supportInvalidateOptionsMenu();
                break;
            case R.id.menu_add_register:
                FragmentManager fm = getSupportFragmentManager();

                NewRegisterFragment dialog = new NewRegisterFragment();
                dialog.setRetainInstance(true);
                dialog.show(fm, "fragment_name");
                break;
            // Listenelement hinzufügen und dem Adapter sagen es hat sich was
            // geändert, mach neu

        }
        return true;
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // TODO Auto-generated method stub
        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                if (helpVisible = true) {
                    // changeFragment();
                    helpVisible = false;
                    getSupportActionBar().setDisplayHomeAsUpEnabled(false);
                    supportInvalidateOptionsMenu();

                }
                break;

        }

        return super.onKeyDown(keyCode, event);
    }

    private void addFragments() {

        // Zuerst versuchen Fragmente aus dem Layout zu laden
        registerListFragment = (RegisterListFragment) getSupportFragmentManager()
                .findFragmentById(R.id.registerListFragment);
        helpFragment = (HelpFragment) getSupportFragmentManager()
                .findFragmentById(R.id.HelpFragment);

        // Wenn die Fragmente nicht im Layout sind, füge sie dynamisch hinzu
        if (registerListFragment == null && helpFragment == null) {

            FragmentTransaction ft = getSupportFragmentManager()
                    .beginTransaction();

            registerListFragment = new RegisterListFragment();

            helpFragment = new HelpFragment();

            ft.setCustomAnimations(android.R.anim.fade_in,
                    android.R.anim.fade_out, android.R.anim.fade_in,
                    android.R.anim.fade_out);

            ft.add(R.id.Fragmentframe, registerListFragment);
            ft.add(R.id.Fragmentframe, helpFragment);
            ft.show(registerListFragment);
            ft.hide(helpFragment);
            ft.commit();

            // OnclickListener für Fragmentwechseln

        }

    }

    private void changeFragment() {

        // Fragmente austauschen
        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();
        if (registerListFragment.isVisible()) {
            ft.hide(registerListFragment);
            ft.show(helpFragment);

            helpVisible = true;
            supportInvalidateOptionsMenu();

            getSupportActionBar().setDisplayHomeAsUpEnabled(true);

            if (getSupportFragmentManager().findFragmentByTag(
                    "RegisterListFragment") == null) {
                ft.addToBackStack("RegisterListFragment");
            }
        } else {
            ft.hide(helpFragment);

            helpVisible = false;
            supportInvalidateOptionsMenu();
            getSupportActionBar().setDisplayHomeAsUpEnabled(false);

            fm.popBackStack();
        }

        ft.commit();
    }

    private void setLargeInLandscape() {
        if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_LARGE) {
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            findViewById(R.id.menu_help).setVisibility(View.GONE);
        }
        if ((getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) == Configuration.SCREENLAYOUT_SIZE_XLARGE) {
            setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
            findViewById(R.id.menu_help).setVisibility(View.GONE);
        }

    }

    @Override
    public void OnRegisterCreated() {
        // TODO Auto-generated method stub
        registerListFragment.refreshData();

    }

to see in the listView "behind" the dialog. I tried so much, but i really didnt get it. Hope you can help me.

Thanks :)

Hamlen

It's not good idea to load data in UI thread. Take a look to CursorLoader (developer.android.com/reference/android/content/…) or custom AsyncTaskLoader. To simply solve your problem you need to create new instance of your adapter and set it to ListView – Daughterly

Answer 1

You can do this

public void refresh(){
     adapter = new RegisterListAdapter(getActivity());
     list.setAdapter(adapter);
}

to refresh the listView or keep the data in memory with a different adapter.

EDIT: Sorry I didn't read well your question the first time, you can write this in your adapter:

public void addNewRow(String row){
    this.data.add(row);
    this.notifyDataSetChanged();
}

Originally

Yeah, that worked for me. But I think this is not the "best practise" for doing this. Do you know how to solve this Problem nicer? Because this way i could also call getActivity.findViewbyId(R.id.list) and then add a new adapter. I think this is not the way you do this. – Hamlen

Answer 2

Try ListView.invalidateViews() refresh content

Dustproof

I tried list.invalidateViews instead of adapter.notifyDataSetChanged(); but it also didn't work -.-' – Hamlen

Be shure that you data is changed before calling. Database.getAlltitles() - is returned result changed anywhen? – Dustproof

The weird thing is that when the first Item is added and i close the Activity and start it again, then it works. I'm really confused. – Hamlen

I think invalidateView will not halp because data loaded one time in adapter constructor. Try to create new instanse of adapter and set it to view – Daughterly

Thanks! This is working for me. You guys need to use together adapter.notifyDataSetChanged(); and after it list.invalidateViews() NOT INSTEAD OF! – Magritte

Answer 3

I use Interface methods. create one Interface class

interface RefreshListview {
fun onValueChanged(myList: ArrayList<ModelTask>)}

In your Activity class implement the Interface and its method

class MenuAct : AppCompatActivity(), View.OnClickListener,RefreshListview

Inside the method take the changed list and set to your CustomAdapter

 override fun onValueChanged(myList: ArrayList<ModelTask>) {
        notesAdapter = AdapterTask(this, myList) // handle your own Adapter and listview `static` initilisations 
        lv_act_menu_daily.adapter = notesAdapter    }

Ohk now we are inside DialogFragment class

private var mCallback: RefreshListview? = null

This is importand

   override fun onAttach(activity: Activity?) {
    super.onAttach(activity)
    try {
        mCallback = activity as RefreshListview?
    } catch (e: ClassCastException) {
        Log.d("MyDialog", "Activity doesn't implement the RefreshListview interface")
    }
}

Inside onActivityCreated

try {
            // handle your actions
            dBHelper.deleteTaskByID(myProg.id!!)
            //get the current listview
            var daily = dBHelper.readAllTask(Util.getInstance(context).currentTime)
            //send it to Interface method  
            mCallback?.onValueChanged(daily)
            dismiss()
        }catch (e:Exception){
            e.printStackTrace()
        }

Berny