发现一直选的NONE。
没有技术基础果然很苦手,查完百度查维基,最后还是不懂,就先眼熟下吧
Meta refresh is a method of instructing a web browser to automatically refresh the current web page or frame after a given time interval, using an HTML meta element with the http-equiv parameter set to "refresh" and a content parameter giving the time interval in seconds. It is also possible to instruct the browser to fetch a different URL when the page is refreshed, by including the alternative URL in the content parameter. By setting the refresh time interval to zero (or a very low value), this allows meta refresh to be used as a method of URL redirection.