iOS定位服务：CLLocation的时间戳问题

Question

I'm developing an iOS 7+ app that needs to get accurate location updates and their timestamp, in order to know the time when a user reaches certain locations. The problem is that the timestamp property of the CLLocation objects received in the locationManager:didUpdateLocations: delegate method seem to depend on the time settings of the device, they aren't universal times. So, since a user can "fake" the time of her device, I can't rely on that information.

ASFAIK, it is possible in Android apps to get the NMEA data from GPS and then get the universal time of positions, but I can´t find that in iOS. Is there any alternative to solve this problem in iOS apps?

EDIT: related to this issue: is it possible to detect if the user changes her device's timezone, date or time while the app is running, even in the background?

Thanks in advance

Answer 1

If you need to get true GEO timestamp from iDevice I think you should call a Time API. Recommend Google Time API. Just submit device's GPS and the local timestamp the API will return timezone, rawOffset, daylight time saving etc... So you can calculate correct device's date time.