iPhoneX适配faceId：苹果官方技术文档:
https://developer.apple.com/documentation/localauthentication/labiometrytype
LAContext *context = [[LAContext alloc] init];
//判断是支持touchid还是faceid
if (@available(iOS 11.0, *)) {
switch (context.biometryType) {
case LABiometryNone:
NSLog(@"-----------touchid，faceid都不支持");
break;
case LABiometryTypeTouchID:
NSLog(@"-----------touchid支持");
break;
case LABiometryTypeFaceID:
NSLog(@"-----------faceid支持");
break;
default:
break;
}
} else {
// Fallback on earlier versions
NSLog(@"-----------iOS11之前的版本，不做id判断");
}
