CODEWITHSUNDEEP
androidlistviewandroid-arrayadapternotifydatasetchanged
Laire
Laire

Reputation: 1330

ArrayAdapter notifyDataSetChanged from AlertDialog doesn't work

I show items from my SQLite database in a Listview. For adding Items I use a AlertDialog. In the ALertDialog I save the item in my database and refresh the List (userLists) with the data from the database. Then I use notifyDataSetChanged but the view does't change.

public class MediUserListsFragment extends Fragment {

    private MediDAO mediDAO;
    private ListView listView;
    private List<UserList> userLists;
    private ArrayAdapter<UserList> adapter;

    @Override
    public View onCreateView(final LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        getActivity().setTitle("Medikamenten Listen");

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

        setHasOptionsMenu(true);

        mediDAO = new MediDAO(getContext());

        userLists = mediDAO.getAllUserList();

        listView = (ListView) view.findViewById(R.id.list_view);

        adapter = new ArrayAdapter<>(getContext(),android.R.layout.simple_list_item_1, userLists);
        listView.setAdapter(adapter);

        Button newLstBtn = (Button) view.findViewById(R.id.new_list_button);
        newLstBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                View alertLayout = inflater.inflate(R.layout.dialog_medi_list_new, null);
                final EditText newLstName = (EditText) alertLayout.findViewById(R.id.newListName);
                AlertDialog.Builder alert = new AlertDialog.Builder(getContext());
                alert.setTitle("Neue Liste");
                alert.setView(alertLayout);
                alert.setCancelable(false);
                alert.setNegativeButton("Abbrechen", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int which) {
                    }
                });
                alert.setPositiveButton("Erstellen", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        mediDAO.newUserList(newLstName.getText().toString());
                        userLists = mediDAO.getAllUserList();
                        adapter.notifyDataSetChanged();
                    }
                });
                AlertDialog dialog = alert.create();
                dialog.show();
            }
        });

        return view;
    }

    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        menu.clear();
        super.onCreateOptionsMenu(menu, inflater);
        inflater.inflate(R.menu.fragment_medi_abc, menu);
    }
}

Upvotes: 4

Views: 2411

Answers (1)

fluffyBatman
fluffyBatman

Reputation: 6704

In your setPositiveButton, try the following.

userLists.clear();
userLists.addAll(mediDAO.getAllUserList());                      
adapter.notifyDataSetChanged();

When you were doing userLists = mediDAO.getAllUserList(); the adapter looses the original data object's reference (which is userLists). With userLists.addAll(), the adapter knows the data object it created with has changed hence, notifyDataSetChanged finds changes to notify.

Upvotes: 5

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