html5横、竖屏状态 以及禁止横屏

<meta name="screen-orientation" content="portrait"><!-- uc强制竖屏 -->
<meta name="x5-orientation" content="portrait"><!-- QQ强制竖屏 -->

window.addEventListener("onorientationchange" in window ? "orientationchange" : "resize", hengshuping, false); function hengshuping() {        if (window.orientation == 90 || window.orientation == -90) {           //横屏        } else {            //竖屏        }    }