I have a very strange behaviour. I'm writing an application that uses both fetch and location background mode (don't know it it's important for the problem). I correctly set up the CLLocationManager with a delegate and I start monitoring significant location changes (startMonitoringSignificantLocationChanges) in the AppDelegate.
Immediately I get called didUpdateLocations that gives me some locations. After that no more events are fired even I simulate a different location in Xcode (also using a GPX file) and even I stop and restart the monitoring. I'm not receiving any location both in background and foreground.
The strange thing is that if I start updating locations (using the GPS) it works correctly (doing the same tests... starting and stopping exactly like with startMonitoringSignificantLocationChanges). Obviously I've both didUpdateLocations and didFailWithError (I receive no errors).
This is my initialisation (called by the initialisation of an object in my AppDelegate didFinishLaunchWithOptions):
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.pausesLocationUpdatesAutomatically = NO;
I know that distanceFilter and accuracy are not important for significant location changes and I've already set pausesLocationUpdatesAutomatically to NO.
Am I missing something? And also does exist a way to read if a location fired is coming from wifi, cellular or gps?
Thanks in advance.
You can simulate location for significant change on simulator only with "freeway drive" option from simulator location menu. It will be triggered with some minutes interval.
Allocate the manager on the main thread and check if the manager or the app has always permissions could do the trick.
Apple's documentation note is:
Note: Significant-change location updates require an authorization
status of kCLAuthorizationStatusAuthorizedAlways.
You can check the status using:
CLAuthorizationStatus status = [CLLocationManager authorizationStatus];
And maybe
if (status != kCLAuthorizationStatusAuthorizedAlways)
You can request permissions again.
Related
I want to use CLLocationManager for updating the users current GPS Location in foreground and background.
I registered the app for using the location background mode in info.plist and under the targets capabilities.
On the iPhone simulator everything works fine but on my real iPhone the function didUpdateLocations just gets called twice when app is in background.
I use a gpx file which simulates GPS data in Xcode. It works when the app is in foreground, I can see the progress on a MapView.
This is the code from my ViewController:
lazy var locationManager: CLLocationManager! = {
let manager = CLLocationManager()
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.delegate = self
manager.requestAlwaysAuthorization()
manager.pausesLocationUpdatesAutomatically = false
//manager.distanceFilter = 250
return manager
}()
//Location manager delegate function
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if(UIApplication.sharedApplication().applicationState == .Background){
print("background call")
}else{
print("foreground call")
}
// Save GPS coordinates
saveGpsCoordinates(locations[0])
}
I’m using:
IOS 9 on an iPhone 5 and Xcode 7.0 beta 5
Does someone have an idea why I don’t get any background delegate calls on my real device?
Thanks.
I had a similar issue after moving to iOS9.
As noted in the answer to the question below, make sure you are setting allowsBackgroundLocationUpdates to YES
allowsBackgroundLocationUpdates in CLLocationManager in iOS9
Two things:
I don't seen anywhere in your code a call to startUpdatingLocation.
(Assuming 1 is correct) You said you are using a GPX file to simulate locations, if you are using a GPX file to simulate locations than that is not using the locationManager to get locations and since you did not call startUpdatingLocation, the locationManager is not actually running in the foreground or background.
Make sure you set pausesLocationUpdatesAutomatically to TRUE. Because you get more location updates when this is set to FALSE, even locations which look the same.
TRUE is also the default value.
you should add NSLocationAlwaysUsageDescription in info.plist. Good luck!
I have created GPS base Application.
In which App logged GPS data every 1 second.
App used the NSTimer to fetch GPS data every second.
This NSTimer is start in background. The NSTimer is start when app received the silent push notification from APNS.
I have seen a problem in iOS 7 that when Phone attached with power cable at that time timer call appropriately but without attached power cable timer stops while App in background.
Any inputs to resolve this issue greatly appreciated.
An NSTimer is not guaranteed to fire if your app is not in foreground. Once you unplug the cable the system puts your app into background to save battery.
Using an NSTimer is not the supported method to get location data. Your CLLocationManager will tell its delegate when there is a new location. No need to poll it.
If you need to track geolocation in background you need to declare location updates as a background mode from the capabilities tab in Xcode 5 target settings. Otherwise your location manager will stop delivering location updates once your app is not in foreground.
There are only few use cases that you can implement for foreground. If you don't want your application to be refused within review please don't use any hacks. Of course, you can use NSTimer in background, but it must be created in thread (runloop) of background task. But this background task lives for the only certain amount of time, so your timer must fire during this period. In other words, your first goal is to create background task, and only then you can use the timer. There are few cases suitable for your purpose (that allow you to create this task): 1.Monitor significant location changes or region 2.Fetch data (iOs 7). So please refer
-(void)application:(UIApplication *)application performFetchWithCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
NSLog(#"BG fetch in action");
//the only 30 sec is allowed to perform all your actions
//during this period you can each second track GPS data
[self performSelector:#selector(finishBackgroundFetch:) withObject:completionHandler afterDelay:27];
[[NSNotificationCenter defaultCenter] postNotificationName:#"StartMyGPSRoutine" object:nil];
}
-(void)finishBackgroundFetch:(void (^)(UIBackgroundFetchResult))completionHandler {
NSLog(#"BG fetch completion handler");
[[NSNotificationCenter defaultCenter] postNotificationName:#"ForceStopAnyBackgroundTaskCreatedWithStartMyGPSRoutine" object:nil];
completionHandler(UIBackgroundFetchResultNewData);
}
of your application delegate -- this will be useful in your case as well as monitor significant location changes.
You ought to put anywhere:
if ([[UIApplication sharedApplication] respondsToSelector:#selector(setMinimumBackgroundFetchInterval:)]) {
NSLog(#"Set Force BG interval to %ld", interval);
[[UIApplication sharedApplication] setMinimumBackgroundFetchInterval:interval];
}
In my case I fetch the GPS data each 5 min so 27sec to complete this task is not so long. Anyway you can play with time intervals with XCode. Please refer Main Menu->Debug->Simulate Background Fetch
I am developing a iPhone app running on iOS5, and am unable to set up geofences when I call the startMonitoringForRegion:desiredAccuracy: method on click of a button.
It works fine in the simulator when I print out the regions in monitoredRegions, but when running on an actual iPhone 4, the monitoredRegions is always empty. Expectedly, the didEnterRegion: and didExitRegion: methods are not called as well.
Another puzzling fact is that on BOTH the simulator and the iPhone 4 device, the CLLocationManagerDelegate method didStartMonitoringForRegion: is never called as well.
Would appreciate some help here, thank you!
EDIT:
this is method that I call on click of a button:
-(void) queueGeofence: (CLLocationCoordinate2D)selectedBranch userCoordinate:(CLLocationCoordinate2D)userCoordinate radius: (CLLocationDegrees)radius {
geofence = [[CLRegion alloc] initCircularRegionWithCenter:selectedBranch radius:radius identifier:#"geofence"];
CLLocationAccuracy acc = kCLLocationAccuracyNearestTenMeters;
[locationManager startMonitoringForRegion:geofence desiredAccuracy:acc];
[CLLocationManager regionMonitoringEnabled];
NSLog([CLLocationManager regionMonitoringEnabled] ? #"regionMonitoringEnabled:Yes" : #"regionMonitoringEnabled:No");
NSLog([CLLocationManager regionMonitoringAvailable] ? #"regionMonitoringAvailable:Yes" : #"regionMonitoringAvailable:No");
NSLog(#"LOCATIONMANAGER monitored regions: %#", [locationManager monitoredRegions]});
}
Region monitoring is both enabled and available, but monitoredRegions is still giving me back nothing.
If you look in CLLocationManager.h, the comments in the header for startMonitoringForRegion:desiredAccuracy: state that
If a region with the same identifier is already being monitored for this application, it
will be removed from monitoring. This is done asynchronously and may not be immediately reflected in monitoredRegions.
Therefore, you shouldn't necessarily expect that [locationManager monitoredRegions] would include your newly added region since it is added asynchronously.
Are you implementing the delegate method for locationManager:monitoringDidFailForRegion:withError:? Maybe that's getting called instead of locationManager:didStartMonitoringForRegion:. Also note that a region with the same identifier as an existing region will get removed, so you might be running into some unexpected problems because you're reusing "geofence" as your identifier.
First of all, you should be sure, that your app has a permission to use LocationManager. Check it when you alloc your manager.
[CLLocationManager authorizationStatus];
I had the same trouble when start app and decline a permission. And after deleting and rebuilding app. I had a flag, that user didn't accept it. Turn it on.
If you are just going by your NSLog, it probably isn't going to work. [locationManager monitoredRegions] returns an NSSet of CLRegions. They won't display to your log that way. Try this:
NSSet *setOfRegions = [locationManager monitoredRegions];
for (CLRegion *region in setOfRegions) {
NSLog (#"region info: %#", region);
}
I'm currently developing an iPhone application which needs location services for various use including AR.
I test everything on simulator and on my iPhone 3GS and everything went well.
I recently tested on iPhone4 and on iPad2 and the location service (the little icon in status bar) keeps displaying even when I manually kill the app!
The only way to disable this icon is to manually stop the location service for my app in the settings.
Does anyone know something about this?
If needed I can post my code.
Thank you in advance
Edit :
When I kill the application, go to location services, switch off my app the location icon disappears. But when I switch it back on, it reappears! Is that normal?
I've found the answer! It came from region monitoring, which I enabled before, but removed all code using it weeks ago.
As I had already tested on the iPad, and even if I deleted and re-installed the app, the system seems to have kept information on region I monitored.
Thus, as described by the documentation, the iOS kept on locating for my App, just as startMonitoringSignificantLocationChanges.
Thanks for you answers, it gave me a better understanding of the location system and how to efficiently use it (in particular thanks to progrmr and Bill Brasky)
Sounds like you're app is going into the background and still using CLLocation. You can stop CLLOcationManager when you receive notification that you're app is resigning active, that's the best way. Then resume when it becomes active. The answer in this question show how to do that here
[EDIT] When your app goes into the background or resigns active for any reason (ie: phone call) you should stop location services at that time. You need to subscribe to the notifications and provide a method to stop and start location services, something like this:
-(void)appDidBecomeActiveNotif:(NSNotification*)notif
{
[locationManager startUpdatingLocation];
}
-(void)appWillResignActiveNotif:(NSNotification*)notif
{
[locationManager stopUpdatingLocation];
}
-(void)viewDidLoad
{
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(appDidBecomeActiveNotif:) name:UIApplicationDidBecomeActiveNotification object:nil];
[[NSNotificationCenter defaultCenter] addObserver:self selector:#selector(appWillResignActiveNotif:) name:UIApplicationWillResignActiveNotification object:nil];
}
-(void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self];
[super dealloc];
}
I ran into this same exact issue when using the region monitoring tools. It didn't matter what I did to disable the regions, the arrow remained. I did finally solve the issue by cleaning up the calls to locationManager. If you are closing your view and don't need the location manager, set it to nil and/or release it. If you are monitoring location in the background, it will stay up there, but if not, make sure you are cleaning up all your location monitoring.
It seems like it is a bug, but as I found out, it is not. Just requires a bit more cleanup.
I have been battling with this problem for a while, and I think I've finally gotten to the bottom of it..
The reason that the location service doesn't stop when you ask it to is not because you haven't stopped it or released it properly. It's actually caused by releasing and re-allocating the CLLocationManager itself, in my experience.
If you have code which releases your CLLocationManager in applicationDidEnterBackground, and then you allocate a brand new one in applicationDidEnterForeground, etc., then you'll probably have this problem.
The solution is this:
Only create your CLLocationManager object once, in applicationDidFinishLaunching.
To start, call startUpdatingLocation, startMonitoringSignificantLocationChanges etc. as normal.
To stop updates, call the appropriate stopUpdatingLocation, stopMonitoringSignificantLocationChanges etc. as normal.
Never, ever release your CLLocationManager or set its' reference to nil (except possibly in applicationWillTerminate, but that probably won't make any difference).
This way, I went from having my app continue to use location services for up to 12 hours after putting my app away in the background, to the location services arrow disappearing within 10 seconds of backgrounding with this new approach.
Note: Tested on iPhone 4S running iOS 5.1.1. To get accurate results on your app's performance in this regard, make sure you go into Settings->Location Services->System Services and turn off the Status Bar Icon switch. That way, the status bar arrow will accurately reflect usage by apps alone.
Presumably this is so users don't need to stare at the bar to notice some mischievous app is using location services. That icon appears when you use any location services and remains for some indeterminate time afterwards.
This is intentional behavior Apple wants users to know which apps are using their locations. It seems this is sensitive data, wouldn't you agree?
This is the solution which fixed this problem for me.
Just stop monitering location changes in
- (void) applicationDidEnterBackground: (UIApplication *)application
{
[locationManager stopMonitoringSignificantLocationChanges];
locationManager.delegate = nil;
}
not in applicationWillEnterForeground: .Still,it takes a few seconds to disappear locating icon.
I don't know why it isn't working in the latter method.
I've run into that problem a while ago and found it useful to apply only one method of applicationDelegate object
- (void)applicationWillEnterForeground:(UIApplication *)application;
If you'll stop your CLLocationManager from receiving updates inside that call, you'll be alright. Of course you'll need to start updating somewhere else, and - (void)applicationDidBecomeActive:(UIApplication *)application; will be a good choice. Also you need to note, that there are two methods of location awareness
the gps based -(void)start/stop_UpdatingLocation;
and the 3g/wi-fi based -(void)start/stop_MonitoringSignificantLocationChanges;
In my app I am using CLLocationManager and AdWhirl. I have made no specific development regarding background mode: I don't want my app to be working when it is in background, i.e. when the user press the "home button", GPS location should no be updated.
Yesterday evening I pressed "home button", and this morning the iPhone was out of battery. It's an iPhone 4 with iOS 4.1, not jailbreaked, and there is no background app running.
The battery was about 35% yesterday evening, and 0% this morning (iPhone was shutdown).
I have set breakpoint in my delegate, which is called each time GPS location is updated. When app is in background mode, delegate is not called. So I'm thinking GPS is really disabled in background mode: ok.
This morning, I am following battery drain: it's about 1% drop each 15 min. I think it a bit too much.
Should I do something specific when the app goes to background mode? Do you think this 1% drop is normal?
Yes, internet access and GPS are two big drains on battery. I don't know at all what you mean with normal, since no other apps are running you've concluded that that is in fact what happens :) Assuming you've tested with NO apps running and didn't get 1% per 15 minutes...
For adwhirl, it's unknown whether it already stops accessing the internet when the app goes into the background, but you can add this to your App Delegate:
- (void)applicationDidEnterBackground:(UIApplication *)application {
/*
Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
If your application supports background execution, called instead of applicationWillTerminate: when the user quits.
*/
[lm stopUpdatingLocation];
[adView ignoreAutoRefreshTimer]
}
- (void)applicationWillEnterForeground:(UIApplication *)application {
/*
Called as part of transition from the background to the active state: here you can undo many of the changes made on entering the background.
*/
[adView doNotIgnoreAutoRefreshTimer]
[lm startUpdatingLocation];
}
(lm and adView are the Location Manager object and the adWhirlView, both declared in the App Delegate. I've found it more useful to do all location managing via methods I make in the App Delegate.)