添加此项以防止缓存上一页：

Add this to prevent caching of the previous page:

header("cache-Control: no-store, no-cache, must-revalidate");
header("cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT");