My ListFragment code
public class ItemFragment extends ListFragment {
private DatabaseHandler dbHelper;
private static final String TITLE = "Items";
private static final String LOG_TAG = "debugger";
private ItemAdapter adapter;
private List<Item> items;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.item_fragment_list, container, false);
return view;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.setHasOptionsMenu(true);
super.onCreate(savedInstanceState);
getActivity().setTitle(TITLE);
dbHelper = new DatabaseHandler(getActivity());
items = dbHelper.getItems();
adapter = new ItemAdapter(getActivity().getApplicationContext(), items);
this.setListAdapter(adapter);
}
@Override
public void onResume() {
super.onResume();
items.clear();
items = dbHelper.getItems(); //reload the items from database
adapter.notifyDataSetChanged();
}
@Override
public void onListItemClick(ListView l, View v, int position, long id) {
super.onListItemClick(l, v, position, id);
if(dbHelper != null) { //item is edited
Item item = (Item) this.getListAdapter().getItem(position);
Intent intent = new Intent(getActivity(), AddItemActivity.class);
intent.putExtra(IntentConstants.ITEM, item);
startActivity(intent);
}
}
}
My ListView
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<ListView
android:id="@android:id/list"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
</LinearLayout>
But this does not refresh the ListView
. Even after restarting app the updated items are not shown. My ItemAdapter
extends BaseAdapter
public class ItemAdapter extends BaseAdapter{
private LayoutInflater inflater;
private List<Item> items;
private Context context;
public ProjectListItemAdapter(Context context, List<Item> items) {
super();
inflater = LayoutInflater.from(context);
this.context = context;
this.items = items;
}
@Override
public int getCount() {
return items.size();
}
@Override
public Object getItem(int position) {
return items.get(position);
}
@Override
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ItemViewHolder holder = null;
if(convertView == null) {
holder = new ItemViewHolder();
convertView = inflater.inflate(R.layout.list_item, parent,false);
holder.itemName = (TextView) convertView.findViewById(R.id.topText);
holder.itemLocation = (TextView) convertView.findViewById(R.id.bottomText);
convertView.setTag(holder);
} else {
holder = (ItemViewHolder) convertView.getTag();
}
holder.itemName.setText("Name: " + items.get(position).getName());
holder.itemLocation.setText("Location: " + items.get(position).getLocation());
if(position % 2 == 0) {
convertView.setBackgroundColor(context.getResources().getColor(R.color.evenRowColor));
} else {
convertView.setBackgroundColor(context.getResources().getColor(R.color.oddRowColor));
}
return convertView;
}
private static class ItemViewHolder {
TextView itemName;
TextView itemLocation;
}
}
Can someone help please?
Look at your onResume
method in ItemFragment
:
@Override
public void onResume() {
super.onResume();
items.clear();
items = dbHelper.getItems(); // reload the items from database
adapter.notifyDataSetChanged();
}
what you just have updated before calling notifyDataSetChanged()
is not the adapter's field private List<Item> items;
but the identically declared field of the fragment. The adapter still stores a reference to list of items you passed when you created the adapter (e.g. in fragment's onCreate).
The shortest (in sense of number of changes) but not elegant way to make your code behave as you expect is simply to replace the line:
items = dbHelper.getItems(); // reload the items from database
with
items.addAll(dbHelper.getItems()); // reload the items from database
A more elegant solution:
1) remove items private List<Item> items;
from ItemFragment
- we need to keep reference to them only in adapter
2) change onCreate to :
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.setHasOptionsMenu(true);
getActivity().setTitle(TITLE);
dbHelper = new DatabaseHandler(getActivity());
adapter = new ItemAdapter(getActivity(), dbHelper.getItems());
setListAdapter(adapter);
}
3) add method in ItemAdapter:
public void swapItems(List<Item> items) {
this.items = items;
notifyDataSetChanged();
}
4) change your onResume to:
@Override
public void onResume() {
super.onResume();
adapter.swapItems(dbHelper.getItems());
}