用来清理ie缓存的，rundll32 -u -p 等方式不好用，根据弹出的对话框可以选择清理缓存，比如cookie, ie cache url history等-Ie used to clear the cache, rundll32-u-p not to use such means, according to the pop-up dialog box can choose to clear the cache, such as cookie, ie cache url history, etc.