iOS8: Blue bar “is Using Your Location” appears sh

问题:

I would like to get the blue bar when tracking in the background, but not when not.

My app uses location services all the time when active, so in iOS8 I use the requestWhenInUseAuthorization on CLLocationManager. Normally, the app stops tracking your location when you close it, but the user can choose the option to let the app track his location in the background as well. Therefore, I have the location option for UIBackgroundModes in the Info.plist file. That works perfectly: when switching to the background, the app keeps getting location updates, and a blue bar appears as a reminder that the app is using location services. All perfect.

But the problem is, that the blue bar appears also when the user has not chosen to track in the background. In that case I simply stop location updates from the AppDelegate when entering the background:

- (void) applicationDidEnterBackground:(UIApplication *)application
{
    if (!trackingInBackground) {
        [theLocationManager stopUpdatingLocation];
    }
}

The Blue bar is shown only for a second after closing the app, but it still looks pretty irritating.

I know that using requestAlwaysAuthorization instead of requestWhenInUseAuthorization will solve the issue, but then I will not get any blue bar at all, also not when tracking in the background is actually on.

I have tried to stopUpdatingLocation already in the applicationWillResignActive: method, but that makes no difference.

Does anybody know how to get the blue bar when tracking in the background, but not when not?

回答1:

We frequently report things to Apple, and sometimes they actually act upon it. Exactly to prevent the blue bar from appearing shortly as described in the question, Apple has introduced a new property on CLLocationManager in iOS-9. Set it at the moment you know you will need the location in the background:

theLocationManager.allowsBackgroundLocationUpdates = YES;

or, in a backward compatible way:

if ([theLocationManager respondsToSelector:@selector(setAllowsBackgroundLocationUpdates:)]) {
    [theLocationManager setAllowsBackgroundLocationUpdates:YES];
}

in Swift:

if #available(iOS 9.0, *) {
    theLocationManager.allowsBackgroundLocationUpdates = true 
}

If this property is not set, then the Blue Bar will not appear when exiting the app, and the user location is not available to your app. Note that in iOS 9, you must set the property in order to be able to use location in the background.

See the WWDC video for Apple's explanation.

回答2:

The blue bar only show when you enable Background Location Updates and request when-in-use authorization in iOS 8.

Blue bar “is Using Your Location” appears shortly after exiting app

Sounds like location manager can't stop immediately. So the blue bar will appear until location manager stop completely. Or maybe it's just a bug like Keith said.

回答3:

To show blue notification you need to add Privacy - Location When In Use Usage Description in Plist file (this is important, with Always Location the blue bar didn´t appear ever)

 self.locationManager.delegate = self;
 self.locationManager.requestWhenInUseAuthorization()
 self.locationManager.pausesLocationUpdatesAutomatically = true/false
 self.locationManager.allowsBackgroundLocationUpdates = true

then star the location: locationManager.startUpdatingLocation()

Also override methods:

 func locationManager(_ manager: CLLocationManager, didUpdateLocations
  locations: [CLLocation]) {
       print(manager.location?.coordinate.latitude ?? "No data")
 }


 func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
     if status == .authorizedWhenInUse {
         if CLLocationManager.isMonitoringAvailable(for: CLBeaconRegion.self) {
             if CLLocationManager.isRangingAvailable() {
                 // do stuff
                 print(manager.location?.coordinate.latitude ?? "No data")
                 locationManager.startUpdatingLocation()
             }
         }
     }
 }

Remember the import!!:

 import CoreLocation

And also remember the Delegate (CLLocationManagerDelegate):

 class ViewController: UIViewController, CLLocationManagerDelegate{

回答4:

If you follow steps below, Blue bar will not appear in background mode

• set NSLocationAlwaysUsageDescription in Info.plist
• check Capabilities > Background Modes > Location Updates
• in code locationManager.requestAlwaysAuthorization()

回答5:

To show blue bar on header that your app is using location when pressing home button you have to set Privacy - Location When In Use Usage Description in Plist file

 self.locationManager.delegate = self;

 locationManager.desiredAccuracy = kCLLocationAccuracyBest

 self.locationManager.requestWhenInUseAuthorization()

 self.locationManager.pausesLocationUpdatesAutomatically = true

 self.locationManager.allowsBackgroundLocationUpdates = true

when you use self.locationManager.requestAlwaysAuthorization() then it will not display blue header

you need only use self.locationManager.requestWhenInUseAuthorization() then it will display blue header when you app is in background that your app is using Location

you have to also set background mode in capabilities in target for location

回答6:

This is not a bug, you still have an active location manager somewhere in you app. Do you have a map view with showsUserLocation = YES for example? That could be it.

I went over my project thoroughly and when i stopped all location managers the bar disappeared when it should.