如何在具有动态大小子项的ListView上使用滚动条

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:scrollbars="vertical"/>

public class MyAdapter extends BaseAdapter {
    private Context context;
    private List<Item> items;

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

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;
        if (convertView == null) {
            convertView = LayoutInflater.from(context).inflate(R.layout.item_layout, parent, false);
            holder = new ViewHolder();
            holder.textView = convertView.findViewById(R.id.textView);
            convertView.setTag(holder);
        } else {
            holder = (ViewHolder) convertView.getTag();
        }

        Item item = items.get(position);
        holder.textView.setText(item.getText());

        return convertView;
    }

    static class ViewHolder {
        TextView textView;
    }
}

<ListView
    android:id="@+id/listView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:scrollbars="vertical"
    android:scrollbarThumbVertical="@drawable/scrollbar_thumb"
    android:scrollbarTrackVertical="@drawable/scrollbar_track"/>