问题
I have a CLLocationManager contained in a singleton and I have added around a dozen regions to monitor. I am successfully notified of boundary crossings when the app is in the foreground/background. However, when I force quit the app, the location icon disappears and I am not getting any callbacks.
回答1:
As far as I can see, this is intended functionality as of iOS7. Here is a reply I found to a similar question, in this case involving significant location change: https://devforums.apple.com/message/882691#882691:
If a user swipes up in the app switcher then the OS will not launch the app unless explicitly told to do so by the user. So no, SLC will not be launching the app, nor will silent notifications. The only thing that will launch the app at that point is the user tapping the icon. The intention here is that the user has expressed their choice of not having that app running any more for any reason, so we honor that. In this situation, there's really nothing that you can do. The next time the user launches the app you can let them know that some of the data may be missing, although you really cannot tell whether there's missing data or not (i.e. you might have been killed by the OS in the background and the user may not have moved thereby not triggering any SLC notifications). My suggestion would be to gather the data you can within the policies of the OS and if the user has manually killed the app then respect that wish and don't do anything. By all means, feel free to file a bug report if this change in behavior winds up causing problems for you or (especially) confusion for your users.
来源：https://stackoverflow.com/questions/19081570/monitoring-regions-but-location-icon-disappears-when-app-is-killed