View holder warning after creating list view

Question

After creating a list view and assigning the text of each item with a different colour, inflater.inflate(R.layout.list_item, parent, false) within View rowView = inflater.inflate(R.layout.list_item, parent, false); becomes highlighted in yellow and I get a warning associated with my view holder. What should the affected code be changed to in order to get rid of this warning?

Unconditional layout inflation from view adapter: Should use View Holder pattern for smoother scrolling

public class FragmentColourChooserList extends android.support.v4.app.Fragment {

    public FragmentColourChooserList() {
        // Required empty constructor
    }

    ListView list_colourchooser;

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View v = inflater.inflate(R.layout.fragment_colour_chooser_list, container, false);

        String[] listContent = {
                getActivity().getResources().getString(R.string.item_0),
                getActivity().getResources().getString(R.string.item_1),
                getActivity().getResources().getString(R.string.item_2),
                getActivity().getResources().getString(R.string.item_3),
                getActivity().getResources().getString(R.string.item_4),
                getActivity().getResources().getString(R.string.item_5),
                getActivity().getResources().getString(R.string.item_6),
                getActivity().getResources().getString(R.string.item_7),
                getActivity().getResources().getString(R.string.item_8),
                getActivity().getResources().getString(R.string.item_9)
        };

        list_colourchooser = (ListView)v.findViewById(R.id.list_colourchooser);
        MyColoringAdapter adapter = new MyColoringAdapter(getActivity(),listContent);
        list_colourchooser.setAdapter(adapter);

        return v;
    }

    private class MyColoringAdapter extends ArrayAdapter<String> {
        private final Context context;
        private final String[] values;

        public MyColoringAdapter(Context context, String[] values) {
            super(context, R.layout.list_item, values);
            this.context = context;
            this.values = values;
        }

        class Holder
        {
            TextView txtView;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View rowView = inflater.inflate(R.layout.list_item, parent, false);
            Holder holder = new Holder();
            holder.txtView = (TextView) rowView.findViewById(R.id.list_item);
            txtView.setText(values[position]);
            int textColorId = R.color.white; // Default color
            switch (position) {
                case 0:
                    textColorId = R.color.brown; break;
                case 1:
                    textColorId = R.color.red; break;
                case 2:
                    textColorId = R.color.yellow; break;
                case 3:
                    textColorId = R.color.green; break;
                case 4:
                    textColorId = R.color.pink; break;
                case 5:
                    textColorId = R.color.grey; break;
                case 6:
                    textColorId = R.color.purple; break;
                case 7:
                    textColorId = R.color.white; break;
                case 8:
                    textColorId = R.color.darkblue; break;
                case 9:
                    textColorId = R.color.lightblue; break;
            }
            txtView.setTextColor(getResources().getColor(textColorId));
            return rowView;
        }
    }
}

The first thing to do would be to search what a ViewHolder is and why you should use it — codeMagic, Jul 30 '15 at 16:47
Since you are new, please use `RecyclerView`, the `ViewHolder` pattern is taken care of for you. — Jared Burrows, Jul 31 '15 at 18:35
After spending so long creating this code!? There's no point (especially without knowing what to change) — wbk727, Jul 31 '15 at 21:32

Parag Kadam · Accepted Answer · 2015-07-31T18:02:46.087

1

Try using a viewHolder class rather than getting values from rowView directly into separate types.

create a holder class

class Holder
{
    private TextView txtView;
    public TextView getTxtView()
    {
        return txtView;
    }
}

try replacing

TextView textView = (TextView) rowView.findViewById(R.id.list_item);

with Holder holderObject = new Holder(); holderObject.getTxtView() = (TextView) rowView.findViewById(R.id.list_item);

edited Jul 31 '15 at 18:02

answered Jul 30 '15 at 17:06

Parag Kadam

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Put it inside the FragmentColourChooserList class or outside that class makes no difference. – Parag Kadam Jul 30 '15 at 18:05
Doesn't work. I now get these warnings: `Class 'Holder' is never used` and `Field 'txtView' is never used` – wbk727 Jul 30 '15 at 18:50
Holder holder = new Holder(); holder.txtView = (TextView) rowView.findViewById(R.id.list_item); Are you doing this as you should? – Parag Kadam Jul 30 '15 at 19:05
Yep. code has been updated and I now get this error: `Cannot resolve symbol 'txtView'` – wbk727 Jul 30 '15 at 20:10
It looks like you have made txtView private. – Parag Kadam Jul 31 '15 at 02:13
How do I not make it private? – wbk727 Jul 31 '15 at 12:57
You can do it private also but then you will have to define its setter-getter methods as well. – Parag Kadam Jul 31 '15 at 17:46
I don't want to do it that way. Can you edit your answer to specify what exactly needs to be done to solve the issue please? – wbk727 Jul 31 '15 at 17:51
Doesn't work - `holderObject.getTxtView()` becomes underlined in red and I now get this error: `Variable expected` – wbk727 Jul 31 '15 at 19:12
If you can mail me your code at paragacem@gmail.com I'll fix it and send back to you. – Parag Kadam Aug 01 '15 at 04:21
Check this [link](http://stackoverflow.com/questions/25381435/unconditional-layout-inflation-from-view-adapter-should-use-view-holder-patter) it should help you. – Parag Kadam Aug 09 '15 at 05:42

View holder warning after creating list view

1 Answers1