自定义列表视图适配器中的单选按钮组滚动值未选中

public class CustomListAdapter extends BaseAdapter {
    private Context context;
    private List<Item> itemList;
    private int selectedPosition = -1;

    public CustomListAdapter(Context context, List<Item> itemList) {
        this.context = context;
        this.itemList = itemList;
    }

    @Override
    public int getCount() {
        return itemList.size();
    }

    @Override
    public Object getItem(int position) {
        return itemList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
            holder = new ViewHolder();
            holder.radioButton = convertView.findViewById(R.id.radioButton);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        final Item item = itemList.get(position);
        holder.radioButton.setChecked(position == selectedPosition);

        holder.radioButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                selectedPosition = position;
                notifyDataSetChanged();
            }
        });

        return convertView;
    }

    private static class ViewHolder {
        RadioButton radioButton;
    }
}