public function delAction($args = null)
 {
     //$id = (int)$_GET['id']; //参数改进
     $id = isset($args['id']) ? (int) $args['id'] : '';
     $where = "pid = '{$id}'";
     //$a = Category::findAll($where);
     //var_dump($a);
     //exit;
     if (!Category::findAll($where)) {
         Category::deleteId($id);
     }
     header('location:index.php?job=admin_category');
 }