/**
  * 页面feed
  * @param null
  * 显示数量由 feed_num决定
  */
 public function listsPage()
 {
     $PostsList = new PostsLogic();
     $post_list = $PostsList->getList(get_opinion('feed_num'), 'page', 'post_id desc', true);
     $RSS = new RSS(get_opinion('title'), '', get_opinion('description'), '');
     // 站点标题的链接
     foreach ($post_list as $list) {
         $RSS->AddItem($list['post_title'], 'http://' . $_SERVER["SERVER_NAME"] . getPageURLByID($list['post_id']), $list['post_content'], $list['post_date']);
     }
     $RSS->Display();
 }