I did write an app using Location services, app must send location every 10s.
And it worked very well.
Just use the "allowDeferredLocationUpdatesUntilTraveled:timeout" method, following Apple's doc.
What I did are:
Required: Register background mode for update Location.
1. Create LocationManger and startUpdatingLocation, with accuracy and filteredDistance as whatever you want:
-(void) initLocationManager
{
// Create the manager object
self.locationManager = [[[CLLocationManager alloc] init] autorelease];
_locationManager.delegate = self;
// This is the most important property to set for the manager. It ultimately determines how the manager will
// attempt to acquire location and thus, the amount of power that will be consumed.
_locationManager.desiredAccuracy = 45;
_locationManager.distanceFilter = 100;
// Once configured, the location manager must be "started".
[_locationManager startUpdatingLocation];
}
2. To keep app run forever using allowDeferredLocationUpdatesUntilTraveled:timeout method in background, you must restart updatingLocation with new parameter when app moves to background, like this:
- (void)applicationWillResignActive:(UIApplication *)application {
_isBackgroundMode = YES;
[_locationManager stopUpdatingLocation];
[_locationManager setDesiredAccuracy:kCLLocationAccuracyBest];
[_locationManager setDistanceFilter:kCLDistanceFilterNone];
_locationManager.pausesLocationUpdatesAutomatically = NO;
_locationManager.activityType = CLActivityTypeAutomotiveNavigation;
[_locationManager startUpdatingLocation];
}
3. App gets updatedLocations as normal with locationManager:didUpdateLocations: callback:
-(void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
// store data
CLLocation *newLocation = [locations lastObject];
self.userLocation = newLocation;
//tell the centralManager that you want to deferred this updatedLocation
if (_isBackgroundMode && !_deferringUpdates)
{
_deferringUpdates = YES;
[self.locationManager allowDeferredLocationUpdatesUntilTraveled:CLLocationDistanceMax timeout:10];
}
}
4. But you should handle the data in then locationManager:didFinishDeferredUpdatesWithError: callback for your purpose
- (void) locationManager:(CLLocationManager *)manager didFinishDeferredUpdatesWithError:(NSError *)error {
_deferringUpdates = NO;
//do something
}
5. NOTE: I think we should reset parameters of LocationManager each time app switches between background/forground mode.
