objective c - Background Location Services not working in iOS 7

Question

I've recently upgraded my iOS devices to use iOS 7. One of the apps that we're developing uses background location services to track device location and all of our testers have reported that the app no longer appears to track in the background under iOS 7.

We have verified that backgrounding for the app is enabled in the settings on the device and the previous build worked flawlessly under iOS 6. Even if the device were cycled, the app would restart after a location update.

Is there something else that needs to be done to make this work under iOS 7?

Answer 1

Here is the solution that I used to get continuous location from iOS 7 devices no matter it is in foreground or background.

You may find the full solution and explanation from blog and also github:-

1. Background Location Update Programming for iOS 7 and 8

2. Github Project: Background Location Update Programming for iOS 7 and 8

Methods and Explanation:-

1. I restart the location manager every 1 minute in function didUpdateLocations

2. I allow the location manager to get the locations from the device for 10 seconds before shut it down (to save battery).

Partial Code Below:-

-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations{

for(int i=0;i<locations.count;i++){
    CLLocation * newLocation = [locations objectAtIndex:i];
    CLLocationCoordinate2D theLocation = newLocation.coordinate;
    CLLocationAccuracy theAccuracy = newLocation.horizontalAccuracy;
    NSTimeInterval locationAge = -[newLocation.timestamp timeIntervalSinceNow];

    if (locationAge > 30.0)
        continue;

    //Select only valid location and also location with good accuracy
    if(newLocation!=nil&&theAccuracy>0
       &&theAccuracy<2000
       &&(!(theLocation.latitude==0.0&&theLocation.longitude==0.0))){
        self.myLastLocation = theLocation;
        self.myLastLocationAccuracy= theAccuracy;
        NSMutableDictionary * dict = [[NSMutableDictionary alloc]init];
        [dict setObject:[NSNumber numberWithFloat:theLocation.latitude] forKey:@"latitude"];
        [dict setObject:[NSNumber numberWithFloat:theLocation.longitude] forKey:@"longitude"];
        [dict setObject:[NSNumber numberWithFloat:theAccuracy] forKey:@"theAccuracy"];
        //Add the vallid location with good accuracy into an array
        //Every 1 minute, I will select the best location based on accuracy and send to server
        [self.shareModel.myLocationArray addObject:dict];
    }
}

//If the timer still valid, return it (Will not run the code below)
if (self.shareModel.timer)
    return;

self.shareModel.bgTask = [BackgroundTaskManager sharedBackgroundTaskManager];
[self.shareModel.bgTask beginNewBackgroundTask];

//Restart the locationMaanger after 1 minute
self.shareModel.timer = [NSTimer scheduledTimerWithTimeInterval:60 target:self
                                                       selector:@selector(restartLocationUpdates)
                                                       userInfo:nil
                                                        repeats:NO];

//Will only stop the locationManager after 10 seconds, so that we can get some accurate locations
//The location manager will only operate for 10 seconds to save battery
NSTimer * delay10Seconds;
delay10Seconds = [NSTimer scheduledTimerWithTimeInterval:10 target:self
                                                selector:@selector(stopLocationDelayBy10Seconds)
                                                userInfo:nil
                                                 repeats:NO];
 }

Update on May 2014: I got a few requests for adding sample codes on sending the location to server for a certain time interval. I have added the sample codes and also combined a fix for BackgroundTaskManager to solve a glitch for background running over an extended period of time. If you have any questions, you are welcomed to join us for a discussion here: Background Location Update Programming for iOS 7 with Location Update to Server Discussion

Update on January 2015: If you want to get the location update even when the app is suspended, please see: Get Location Updates for iOS App Even when Suspended