I am using SimpleCursorAdapter
trying to display data which comes from a content provider. But the ListView
stays empty. Have been searching for an answer for 3 days.
Here is my code:
IssuesFragment.java
public class IssuesFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> {
private SimpleCursorAdapter issuesAdapter;
private static final int ISSUES_LOADER = 0;
private static final String[] ISSUES_COLUMNS = {
DbContract.issues._ID,
DbContract.issues.ID,
DbContract.issues.THUMBNAIL,
DbContract.issues.TEXT
};
public static final int COL_ISSUES__ID = 0;
public static final int COL_ISSUES_ID = 1;
public static final int COL_ISSUES_THUMBNAIL = 2;
public static final int COL_ISSUES_TEXT = 3;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
public IssuesFragment() {
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
getLoaderManager().initLoader(ISSUES_LOADER, null, this);
super.onActivityCreated(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_issues, container, false);
ListView listView = (ListView) rootView.findViewById(R.id.issues_listview);
getLoaderManager().initLoader(ISSUES_LOADER, null, this);
issuesAdapter = new SimpleCursorAdapter (
getActivity(),
R.layout.issues_list_item,
null,
ISSUES_COLUMNS,
new int[]{
R.id.issues_list__id,
R.id.issues_list_id,
R.id.issues_list_thumbnail,
R.id.issues_list_text,
},
0
);
listView.setAdapter(issuesAdapter);
return rootView;
}
@Override
public void onResume() {
super.onResume();
}
@Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
Uri issuesEntry = DbContract.issues.buildIssuesUri();
return new CursorLoader(
getActivity(),
issuesEntry,
ISSUES_COLUMNS,
null,
null,
null
);
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
issuesAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader) {
issuesAdapter.swapCursor(null);
}
}
Here are the corresponding Layout files:
issues_list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:minHeight="?android:attr/listPreferredItemHeight"
android:orientation="horizontal"
android:padding="16dp">
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/issues_list__id" />
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/issues_list_id" />
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/issues_list_thumbnail" />
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/issues_list_text" />
</LinearLayout>
fragment_issues.xml
<LinearLayout
....
/>
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="@+id/issues_listview"
android:layout_weight="1" />
<TextView
android:id="@+id/emptyListElem"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:gravity="center"
android:text="Keine Ausgaben vorhanden." />
</LinearLayout>
My cursor gets filled with data. I verified that by printing DatabaseUtils.dumpCursorToString(cursor)
within the onLoadFinished
Method. But the data doesn't get from there to the UI.
I found out what the problem was. The element emptyListElem Textview from fragment_issues.xml was replacing the list element, even though i had
View empty = getActivity().findViewById(R.id.emptyListElem);
listView.setEmptyView(empty);
in my onCreateView method which AFAIK should make the emptyListElem show up only if there is no content to fill the list. Seems like i was mistaken. Or maybe i had the code in the wrong place.
edit: i removed the Element emptyListElem and it works now.