获取屏幕旋转角度

[yangbo5207]

var screen = window.screen;
var orientation = screen.orientation || screen.mozOrientation || screen.msOrientation;
var angle = orientation && orientation.angle || window.orientation;
var mm;

if(angle == null && typeof window.matchMedia == 'function') {
    mm = window.matchMedia('(orientation: landscape)')

    if(mm.matches) {  /* 匹配查询成功，但是无法区别横屏方向 */
        angle = 90;
    }
}