CLLocation Manager work only for the application first run.
This is my code.
self.locationManager = [[CLLocationManager alloc] init];
self.locationManager.delegate = self;
self.locationManager.distanceFilter = kCLDistanceFilterNone;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
if ([self.locationManager respondsToSelector:#selector(requestAlwaysAuthorization)])
{
[self.locationManager requestAlwaysAuthorization];
}
[self.locationManager startUpdatingLocation];
I found the solution, the probleme was from simulator when you restart the application the location turn to the default location which is none.
So when i restart my app i got the the error didFailWithError: Error Domain=kCLErrorDomain Code=0.
You should when reopen the application choose a new location from debug -> location, or use a device for test.
Try the freeway drive in the location debug for simulator to test your location, when you close the app location go to none.
Change it to freeway drive
Related
I'm trying to get my location in simulator. A couple of time it worked but... Now I always get 0.000000 as my location. There is code that I used:
#import <CoreLocation/CoreLocation.h>
CLLocationManager *locationManager = [[CLLocationManager alloc] init];
[locationManager startUpdatingLocation];
CLLocation *location = [locationManager location];
CLLocationCoordinate2D coordinate = [location coordinate];
NSLog(#"%f",location.coordinate.latitude);
NSLog(#"%f",location.coordinate.longitude);
After running app I change in the simulator Debug -> Location -> Custom Location... Does somebody can explain why does it stop working?
This will never work, except by accident:
[locationManager startUpdatingLocation];
CLLocation *location = [locationManager location];
When you call startUpdatingLocation you get delegate messages (assuming you have a location manager delegate, which you should, always) — in particular, locationManager:didUpdateLocations:. That is where you receive information about your location.
I am using the below code to get coordinates on click of a button
-(CLLocationCoordinate2D) getLocation{
CLLocationCoordinate2D coordinate;
CLLocationManager *locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
if ([CLLocationManager locationServicesEnabled]) {
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = kCLDistanceFilterNone;
[locationManager startUpdatingLocation];
[locationManager startUpdatingLocation];
CLLocation *location = [locationManager location];
coordinate = [location coordinate];
}
else {
coordinate.latitude = 0.0;
coordinate.longitude = 0.0;
}
return coordinate;
}
When the button is clicked for the first time, I do get my valid coordinates, but if I click the button again, The latitude and longitude values are 0.0000
Any suggestions
Please initialize the CLLocationManager outside the method.Take the You can initialize in viewdidload method.
It may helps to you
You cannot expect [locationManager location] to return anything useful immediately after activating a location manager with [locationManager startUpdatingLocation] .
CLLocationManager takes time to acquire a location. You need to set the CLLocationManager's delegate (eg, to 'self') and then use the delegate method - (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray<CLLocation *> *)locations; to get notified when the location manager has got a location that you can use.
See: https://developer.apple.com/reference/corelocation/cllocationmanagerdelegate/1423615-locationmanager?language=objc
(If you only want one location, and not a continuous stream of location updates, instead of calling 'startUpdatingLocation' call [locationManager requestLocation] - but even then you still need to use the delegate method to be notified when a location has been acquired).
You need to split out the code for creating and starting the location manager to where it is only run once (only need one location manager for the app) - eg, viewDidLoad. Then the rest of the code, to process the locations acquired, should go in the delegate method.
In reality, if you want you button click to have a location immediately, you need to have your location manager running and updating locations before your button is available to be clicked. Eg, make your button enabled=NO and when you start getting locations via the delegate method, set the button enabled=YES.
I have a app which collects location data in foreground and background. To save battery i want to use the allowDeferredLocationUpdatesUntilTraveled property as explained in Apple Doc
From the documents, allowDeferredLocationUpdatesUntilTraveled gets set(based on time and distance) in foreground. Once app goes in the background we won't receive regular location updates instead we receive them based on the allowDeferredLocationUpdatesUntilTraveled.
I have implemented following code but the deferring does not get called in the background.
#pragma mark - Location Manager
-(void) setLocationManager
{
locationManager = [[CLLocationManager alloc] init];
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.delegate = self;
[locationManager startUpdatingLocation];
}
-(void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
NSLog(#"didUpdateLocations");
if (!deferringUpdates)
{
CLLocationDistance distance = 200;
NSTimeInterval time = 60;
[locationManager allowDeferredLocationUpdatesUntilTraveled:distance timeout:time];
deferringUpdates = YES;
}
}
-(void)locationManager:(CLLocationManager *)manager didFinishDeferredUpdatesWithError:(NSError *)error
{
NSLog(#"didFinishDeferredUpdatesWithError");
}
SetLocationManager gets called in the foreground and works fine. Once app goes in the background i still receive regular location updates rather than allowDeferredLocationUpdatesUntilTraveled.
I have also set the following values in the info.plist file
Background Fetch
Background Location Updates
Device Capabilities - location service
Anyone luck with implementing this?
You need to set deferringUpdates back to NO within didFinishDeferredUpdatesWithError : as per Apple documentation, the "delegate’s locationManager:didFinishDeferredUpdatesWithError: method is called exactly once for each time you call (allowDeferredLocationUpdatesUntilTraveled)".
Thus allowDeferredLocationUpdatesUntilTraveled is only called once until deferringUpdates is NO.
I have a view with a map and a button (like the Maps app once) that allows the user to center and zoom his current location on the map. If I can not use the locationServicesEnabled method (always returns YES), should I create a BOOL attribute to check if the didFailWithError method is called and know if I can call the button method?
Thanks for reading.
Edited:
This code does not work for me. I am using the simulator. I am always getting YES when asking locationServicesEnabled.
// Gets the user present location.
- (IBAction)locateUser:(id)sender {
if([CLLocationManager locationServicesEnabled]) {
CLLocationCoordinate2D coordinate;
coordinate.latitude = self.mapView.userLocation.location.coordinate.latitude;
coordinate.longitude = self.mapView.userLocation.location.coordinate.longitude;
[self zoomCoordinate:coordinate];
} else {
[[[[UIAlertView alloc] initWithTitle:#"Warning." message:#"Location services are disabled."
delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil] autorelease] show];
}
}
In Preferences you have two options to disable the location services. The first option is a global switch to disable the location service for all apps "[CLLocationManager locationServicesEnabled]". The second option let you disable the location service for some apps but not for all apps.
To check if its disabled globally and if its disabled for your app use following:
if([CLLocationManager locationServicesEnabled] &&
[CLLocationManager authorizationStatus] != kCLAuthorizationStatusDenied)
{
...
}
"locationServicesEnabled" checks if the user has enabled Location Services in Preferences. Your MapView probably checks this value already and should not set any values to "self.mapView.userLocation" if Location Services are not available. This SO question might give you some more info.
I run into this problem too and still be finding the answer.
take care that authorizationStatus requires iOS4.2+ and + (BOOL)locationServicesEnabled requires iOS4.0... And for previous iOS versions, it is - (BOOL)locationServicesEnabled...
- (BOOL) enableLocationServices
{
if ([CLLocationManager locationServicesEnabled])
{
self.locationManager.distanceFilter = 10;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[self.locationManager startUpdatingLocation];
[self.mapview setUserTrackingMode:MKUserTrackingModeFollow animated:YES];
return YES;
}
else
{
return NO;
}
}
I am developing an app that has many view. Into my app sometimes the user arrives to a view where he can ask for his position clicking over a button. I am trying to follow the Apple guide lines to only ask for the user position if the user allows to do it. What should I do, use the next first code into the app delegate and declare a location manager attribute into any view that the user invokes, passing the location manager attribute to the new view and from the old view and asking with the second next code anytime that the user clicks the button to locate himself?; or just use the second code, declaring a location manager attribute only into the views that allow to get the user location with a button, to check if the location services are enable?
First snippet.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
// Add the navigation controller's view to the window and display.
[window addSubview:navigationController.view];
[window makeKeyAndVisible];
// Create a location manager instance to determine if location services are enabled. This manager instance will be
// immediately released afterwards.
CLLocationManager *manager = [[CLLocationManager alloc] init];
if (manager.locationServicesEnabled == NO) {
UIAlertView *servicesDisabledAlert = [[UIAlertView alloc] initWithTitle:#"Location Services Disabled" message:#"You currently have all location services for this device disabled. If you proceed, you will be asked to confirm whether location services should be reenabled." delegate:nil cancelButtonTitle:#"OK" otherButtonTitles:nil];
[servicesDisabledAlert show];
[servicesDisabledAlert release];
}
[manager release];
return YES;
}
Second snippet.
- (IBAction)locateUser:(id)sender {
if([CLLocationManager locationServicesEnabled]) {
self.locationManager = [[[CLLocationManager alloc] init] autorelease];
self.locationManager.delegate = self;
} else {
[[[[UIAlertView alloc] initWithTitle:#"Location services."
message:#"Location services are disabled."
delegate:nil
cancelButtonTitle:#"OK"
otherButtonTitles:nil] autorelease] show];
}
}
Thanks for reading.
CoreLocation will handle all the alerts for you. If locations services are disabled and that you ask for the location, CoreLocation will show an alert telling so to the user with a button to go directly to Settings.app.
If you want to know what append you can check for the delegate call
- (void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
The error here contains a code that will be kCLErrorDenied if the user doesn't let the app use location services.
Also, you should use CoreLocation when the user need it. It's not necessary to check for location services at launch and the overhead of multiple CLLocationManager is almost inexistent.