探索关于手机适配的问题

Js判断iPhone XS、iPhone XS Max、iPhone XR适配

iPhone X、iPhone XS

js
var isIPhoneX = /iphone/gi.test(window.navigator.userAgent) 
    && window.devicePixelRatio 
    && window.devicePixelRatio === 3 
    && window.screen.width === 375 
    && window.screen.height === 812;

iPhone XS Max

js
var isIPhoneXSMax = /iphone/gi.test(window.navigator.userAgent) 
    && window.devicePixelRatio
    && window.devicePixelRatio === 3 
    && window.screen.width === 414 
    && window.screen.height === 896;

iPhone XR

js
var isIPhoneXR = /iphone/gi.test(window.navigator.userAgent) 
    && window.devicePixelRatio 
    && window.devicePixelRatio === 2 
    && window.screen.width === 414 
    && window.screen.height === 896;

依旧不用安全区域代码，如果要做刘海头 if (isIPhoneX || isIPhoneXSMax || isIPhoneXR) 垫高44px。 区分关键点：

1.是否需要考虑横屏情况

2.内补以及顶部固定显示需要动态控制显示