Php Joomla组件分页不'；行不通

我正在构建一个Joomla组件，并试图为我的列表创建分页，但没有显示任何内容 这是default.php的代码

<tfoot>
            <tr>
                <td colspan="5">
                    <?php echo $this->pagination->getListFooter(); ?>
                </td>
            </tr>
        </tfoot>

有什么不对吗

protected $patients;
protected $pagination;
public $filterForm;
public $activeFilters;
 public function display($tpl = null)
{

    $this->patients = $this->get('Items');
    $this->pagination   = $this->get('Pagination');
    $this->filterForm    = $this->get('FilterForm');
    $this->activeFilters = $this->get('ActiveFilters');
    labHelper::addSubmenu('patients');
    $this->addToolBar();
    $this->sidebar = JHtmlSidebar::render();

    return parent::display($tpl);
}