适配iphone的刘海和小黑条

//苹果X系列检测
function modelDiscern(){
if(/iphone/gi.test(window.navigator.userAgent)){
/* iPhone X、iPhone XS /
var x=(window.screen.width === 375 && window.screen.height === 812);
/ iPhone XS Max /
var xsMax=(window.screen.width === 414 && window.screen.height === 896);
/ iPhone XR */
var xR=(window.screen.width === 414 && window.screen.height === 896);
if(x || xsMax || xR){
return true;
}else{
return false;
}
}else{
return false
}
}