判断手机是否竖屏

isPortrait.js

export function isPortrait () {
  if (!/ios|iphone|ipad|Macintosh/i.test(window.navigator.userAgent)) { // iphone 只会保留竖屏的宽高
    return window.screen.width < window.screen.height
  }
  return (window.orientation === 180 || window.orientation === 0)
}