code: public function getHtml($tpl = '') 
      {
          if (!$this->isParsed) {
              $this->parseArgs();
          }
          
          $tpl || $tpl = $this->tpl;
          $viewFile = __DIR__ . "/view/{$tpl}.php";
          
          ob_start();
          include $viewFile;
          return ob_get_clean();
      }
docs: 获取导航条html
  @param string $tpl = '' 选择使用导航条模板， mobile）手机分页, simple）简单分页, complex）复杂分页