iPhone X,XS，XSMax，XR的兼容问题

设备型号	devicePixelRatio	screen.width	screen.height	图片选择@3x/2X
X/XS	3	375	812	@3x
XSMax	3	414	896	@3x
XR	2	414	896	@2x

css兼容：（用媒体查询方式）

@media only screen and (device-width: 375px) and (device-height:812px) and (-webkit-device-pixel-ratio:3) {
	.list-choose  .list-choose-footer{
		bottom: pxTorem(22)!important;
	}
}
@media only screen and (device-width: 414px) and (device-height:896px) and (-webkit-device-pixel-ratio:3) {
	.list-choose  .list-choose-footer{
		bottom: pxTorem(22)!important;
	}
}
@media only screen and (device-width: 414px) and (device-height:896px) and (-webkit-device-pixel-ratio:2) {
	.list-choose  .list-choose-footer{
		bottom: pxTorem(22)!important;
	}
}