Ravi Ravi - 6 months ago 84
Android Question

Custom Adapter getView() method is not called

Here is the code of the fragment in which I am setting a custom adapter to the list.

There no errors but the

ListView
is empty. I have implemented
getCount()
which returns right number of items in my ArrayList. I don't see
("Inside", "GetView")
in the logcat

Fragment

public class ServiceCarListFragment extends Fragment {

private String url;
private ArrayList<CarDetail> carDetailList = new ArrayList<CarDetail>();
private CarListAdapter adapter;
private ListView mList;

@Override
public void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
url = getActivity().getIntent().getStringExtra("url");
new DownloadCarDetail().execute(url);
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View v = inflater.inflate(R.layout.fragment_service_car_list, container, false);
mList = (ListView) v.findViewById(R.id.list);
mList.setAdapter(adapter);

for (CarDetail car : carDetailList) {
// START LOADING IMAGES FOR EACH STUDENT
car.loadImage(adapter);
}
return v;
}

class DownloadCarDetail extends AsyncTask<String, String, ArrayList<CarDetail>> {

@Override
protected ArrayList<CarDetail> doInBackground(String... params) {
// TODO Auto-generated method stub
ArrayList<CarDetail> carDetailList = JsonParser.parseJson(params[0]);
return carDetailList;
}

@Override
protected void onPostExecute(ArrayList<CarDetail> carDetailList) {
// TODO Auto-generated method stub
ServiceCarListFragment.this.carDetailList = carDetailList;
Log.d("dccs", String.valueOf(ServiceCarListFragment.this.carDetailList.size()));
adapter = new CarListAdapter(getActivity(), ServiceCarListFragment.this.carDetailList);
Log.d("dccs", String.valueOf((adapter.getCount())));
}

}
}


CustomAdapter

public class CarListAdapter extends BaseAdapter {

private ArrayList<CarDetail> items = new ArrayList<CarDetail>();
private Context context;

public CarListAdapter(Context context, ArrayList<CarDetail> items) {
this.context = context;
this.items = items;
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return items.size();
}

@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return items.get(position);
}

@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Log.d("Inside", "GetView");
LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Activity.LAYOUT_INFLATER_SERVICE);
ViewHolder holder = null;
CarDetail car = items.get(position);

if (convertView == null) {
convertView = mInflater.inflate(R.layout.car_list_row, null);
holder = new ViewHolder();
holder.tvCarName = (TextView) convertView.findViewById(R.id.tvCarName);
holder.tvDailyPriceValue = (TextView) convertView.findViewById(R.id.tvWeeklyPriceValue);
holder.tvWeeklyPriceValue = (TextView) convertView.findViewById(R.id.tvWeeklyPriceValue);
holder.imgCar = (ImageView) convertView.findViewById(R.id.imgCar);
convertView.setTag(holder);
} else {
holder = (ViewHolder) convertView.getTag();
}

holder.tvCarName.setText(car.getCarName());
if (car.getImage() != null) {
holder.imgCar.setImageBitmap(car.getImage());
} else {
// MY DEFAULT IMAGE
holder.imgCar.setImageResource(R.drawable.ic_action_call);
}

return convertView;
}

static class ViewHolder {
TextView tvCarName;
TextView tvDailyPriceValue;
TextView tvWeeklyPriceValue;
ImageView imgCar;
}

}

Answer

the only reasons getView is not called are:

  1. getCount returns 0
  2. you forget to call setListAdapter on the ListView.
  3. If the ListView's visibility (or its container's visibility) is GONE. Thanks to @Tayn√£Bonaldo for the valuable input
  4. ListView is not attached to any viewport layout. That is, mListView = new ListView(...) is used without myLayout.addView(mListView)

In the onPostExcute, after you create a new instance of CarListAdapter I will suggest you to update the new instance to your ListView. Indeed you need to call again

 mList.setAdapter(adapter);

Edit: setAdapter should be always called on the ui thread, to avoid unexpected behaviours

Edit2: you are using the new RecyclerView, make sure that the getItemCount in your Adapter's subclass is returning the size of the dataset, and not an hard-coded 0