Why is my ListView empty after calling setListAdapter inside ListFragment?

Question

I am trying to populate a ListView with data from a web service using Retrofit, but my ListView is somehow always empty. I am getting the data from the web service fine, it just isn't getting into the ListView. setListAdapter() doesn't seem to be doing anything because the listview's count is 0 after I call it. Why is my ListView empty? Here is some of my code:

public class PopularFragment extends ListFragment{

private final String NAME = "Popular";

RestClient restClient;


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

    restClient = RestClientService.getService();

    restClient.getApps(new Callback<List<App>>() {
        @Override
        public void success(List<App> apps, Response response) {
            Log.v("test", apps.toString());

            setListAdapter(new AppListAdapter(getActivity(), apps));

            Log.v("test", Integer.toString(getListAdapter().getCount()));
            Log.v("test", Integer.toString(getListView().getCount()));
        }

        @Override
        public void failure(RetrofitError retrofitError) {
            Log.v("test", "failure");
        }
    });
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_browse_apps, container, false);

    return view;
}

The two log methods Log.v("test", Integer.toString(getListAdapter().getCount())); and Log.v("test", Integer.toString(getListView().getCount())); both return 0.

Here is my custom adapter:

public class AppListAdapter extends ArrayAdapter<App>
{
private final Context context;
private List<App> apps;

public AppListAdapter(Context context, List<App> apps)
{
    super(context, R.layout.app_list_item);
    this.context = context;
    this.apps = apps;
}

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    View view = convertView;

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (convertView == null) {
        view = inflater.inflate(R.layout.app_list_item, parent, false);
    }

    App app = this.apps.get(position);

    TextView appName = (TextView) view.findViewById(R.id.appName);
    appName.setText("TEST");

    return view;
}
}

app_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="match_parent"
android:orientation="vertical" >

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="App Name"
    android:id="@+id/appName" />

fragment_browse_apps.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.android.devon.appfrenzy.BrowseAppsActivity$PlaceholderFragment">

<TextView
    android:id="@+id/section_label"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="HELLO" />

<ListView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@android:id/list"
    android:layout_centerHorizontal="true" />

Loleta

What does apps look like? Are you sure it's populated? – Waac

yes I am sure it is populated – Loleta

Answer 1

You should call the 3 variable constructor for the ListAdapter:

public AppListAdapter(Context context, List<App> apps)
{
    super(context, R.layout.app_list_item,apps);
    this.context = context;
}

Then you don't actually need to store apps off, it can be retrieved using getItem

@Override
public View getView(int position, View convertView, ViewGroup parent)
{
    View view = convertView;

    LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (convertView == null) {
        view = inflater.inflate(R.layout.app_list_item, parent, false);
    }

    App app = getItem(position);

    TextView appName = (TextView) view.findViewById(R.id.appName);
    appName.setText("TEST");

    return view;
}

Waac