didUpdateToLocation called multiple - objective-c

Question

i have an iOS application witch uses the current location of the user. I am doing like this :
-(void)startGeoloc{
NSLog(#"start geoloc");
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.desiredAccuracy=kCLLocationAccuracyHundredMeters;
[locationManager startUpdatingLocation];
}
#pragma mark - CLLocationManagerDelegate methods
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation
{
[locationManager stopUpdatingLocation];
AppDelegate *apDelegate =(AppDelegate *)[UIApplication sharedApplication].delegate;
apDelegate.modeGeoloc = YES;
[self callWebService:locationManager.location];
}
The problem of this, is that my method callWebService:locationManager.location is called twice and i would like to call it just one time. how i can i do this ? thanks for your answers

Answer 1

To ensure locationManager only calls the "didUpdate..." method once, use a BOOL to reference if the location has been found yet.
Create the ivar BOOL:
#property BOOL didFindLocation;
Before locationManager startUpdatingLocation, set the new BOOL to NO. That way you can call for a new location update at will.
-(void) startFindingLocation {
self.didFindLocation = NO; // like this
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self]
[locationManager setDesiredAccuracy:kCLLocationAccuracyHundredMeters];
[locationManager startUpdatingLocation];
}
In "didUpdateLocations", check for it.
- (void) locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
if (!self.didFindLocation) {
self.didFindLocation = YES;
[locationManager stopUpdatingLocation];
// do the rest of your stuff
}
}
If possible, do not set didFindLocation anywhere else in your code to avoid confusion.

Answer 2

locationManager delegate methods can be called very frequently (they didUpdateToLocation all the time, right? :)
One way would be to have your callWebService have state, know whether it is currently executing a request and ignore concurrent requests if one is still going. Another way would be to keep a timestamp and only allow it through if 2 minutes has passed since the previous one.

Answer 3

Had the same problem.
I think the easiest solution is setting the CLLocationManager to null.
locationManager = nil;
after calling
[locationManager stopUpdatingLocation];

Answer 4

locationManager.startUpdatingLocation() fetch location continuously and didUpdateLocations method calls several times,
Just set the value for locationManager.distanceFilter value before calling locationManager.startUpdatingLocation().
As I set 100 meters(you can change as your requirement) working fine, and will work for you.
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.distanceFilter = 100
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()