http://www.xxx.com/index/product/index/id/7/page/4.html
$pages=input('param.page/d');
$options=[
'page'=>$pages,
'path'=>url('index/product/index',"id=$sid",false)."/page/[PAGE].html",
];
$list=Db::name('product')->where('cid','in',$cas)->order(' sort desc,id asc')->paginate(1,false,$options);
$page = $list->render();
$this->assign('page',$page);
$this->assign('list',$list);
return $this->fetch(); 