Android listview using ViewHolder

Change your code at below. I think you’re missing that.

public class AlphabeticalAdapter extends ArrayAdapter<String> {
    int layoutResourceId;
    private final Context context;
    private List<String> data;
    private List<String> tags;
    private ProgressDialog mProgressDialog;
    private ImageView downloadImageButton;

    public AlphabeticalAdapter(Context context, int resource, List<String> data) {
        super(context, resource, data);
        this.layoutResourceId = resource;
        this.context = context;
        this.data = data;
        tags = new ArrayList<String>();
        int size = data.size();
        for (int i = 0; i < size; i++) {
            tags.add("tag");
        }
    }

    static class ViewHolder {
        ImageView downloadImageButton;
        TextView catlogTitle;
        ImageView icon;
        int position;
    }

    public View getView(final int position, View convertView, ViewGroup parent) {

        // View rowView = convertView;
        final ViewHolder viewHolder;

        if (convertView == null) {
            LayoutInflater inflater = (LayoutInflater) context
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            // convertView = inflater.inflate(R.layout.catalogslist_single_row,
            // parent, false);
            viewHolder = new ViewHolder();
            viewHolder.position = position;
            viewHolder.downloadImageButton
                    .setOnClickListener(new OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            System.out.println("DOWNLOAD PRESSED");
                            viewHolder.downloadImageButton.setTag("downloaded");
                            tags.add(position, "downloaded");
                        }
                    });
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.catlogTitle.setText(data.get(position));
        viewHolder.catlogTitle.setTypeface(regularDin);
        viewHolder.icon.setImageResource(R.drawable.cata);

        if (tags.get(position) == "downloaded") {
            downloadImageButton.setImageResource(R.drawable.icon_ok);
        } else {
            downloadImageButton.setImageResource(R.drawable.icon_download);
        }

        viewHolder.position = position;
        return convertView;
    } // close getView
}