Android: Problem With ListViews and CheckBoxes

Question

I have a ListView, and within each list item I have some TextViews and a CheckBox. When I check a CheckBox and my onCheckedChangeListener fires, everything works as it should. However, random other checkboxes get checked once one is checked. Here is an example.

If I click on the first CheckBox: 8 is checked. 15 is checked. 21 is checked. 27 is checked. 33 is checked. 41 is checked. Then if I scroll all the way up, none are checked until 6. The next being 13.

Basically... what is going on?

Answer 1

It seems that you are reusing the convertView that is passed on the getView() method that you implement.

Android will try to use the same view for different items in a ListView. You will either need to (1) uncheck/check manually the checkbox that is inside the returned item (always call setChecked before returning on getView or (2) don't use convertView, but return a new View from getView.

(1) is recommended, I think.

Answer 2

works fine for me

public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {

        final ViewHolder holder;
        final Season season = (Season) getGroup(groupPosition);
        if (convertView == null) {
            LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            convertView = vi.inflate(R.layout.season, parent, false);
            holder = new ViewHolder();
            holder.title = (TextView) convertView.findViewById(R.id.season_title);
            holder.checkBox = (CheckBox) convertView.findViewById(R.id.season_check_box);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        holder.title.setText(season.getTitle());
        holder.checkBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                season.setChecked(isChecked);
                adapter.notifyDataSetChanged();
            }
        });

        holder.checkBox.setChecked(season.isChecked()); // position is important! Must be before return statement!
        return convertView;
    }

    protected class ViewHolder {
        protected TextView title;
        protected CheckBox checkBox;
    }