CLLocationManager doesn't get location

Question

I'm Using CLLocationManager to get the current location of the device and i tried to get the location property in order to get the longitude and latitude as follows:

-(void)getCurrentLocation{
CLLocationManager *manager=[[CLLocationManager alloc]init];;
manager.delegate=self;
manager.desiredAccuracy=kCLLocationAccuracyBest;
self.currentLocation=manager.location;
NSLog(@"Current Lat :%f",self.currentLocation.coordinate.latitude);
NSLog(@"Current Long :%f",self.currentLocation.coordinate.longitude);

[manager startUpdatingLocation];
}

Given that:

self.currentLocation is a property inside my class (Which is the CLLocationManagerDelegate) as follows:

.h

@property(nonatomic,strong) CLLocation *currentLocation;

and the getter in the .m is as follows:

-(CLLocation *)currentLocation{
if (!_currentLocation) {
    _currentLocation=[[CLLocation alloc]init ];
}
return _currentLocation;

}

I forget to say that i have implemented the didUpdateToLocation Method as follows:

-(void)locationManager:(CLLocationManager *)manager
didUpdateToLocation:(CLLocation *)newLocation
      fromLocation:(CLLocation *)oldLocation {
NSLog(@"didUpdateToLocation");
CLLocation *loc=newLocation;
if (loc!=nil) {
    self.currentLocation=loc;

}  

}

I also tried to put this statement after the startUpdateLocation call:

    self.currentLocation=manager.location;

the problem is that when i call the previous function getCurrentLocation the two NSLogs inside it prints 0.000000 which means that manager.location isn't working and the weird thing is that the first NSLog inside didUpdateToLocation doesn't printed , thanks in advance

You should implement the CLLocationManagerDelegate methods (notably, locationManager:didUpdateLocations:) and wait until you get called there. You should view this process of starting location manager and waiting for responses as an asynchronous process. — Rob
Please note that didUpdateToLocation is deprecated as of iOS 6.0! Use didUpdateLocations as in my example instead. Your problem is that your delegate method is not called until a later point in time. Could be 10 ms, or a few seconds. Depends on the GPS signal etc. Try and move your NSLog calls to the delegate method as implemented in my exmaple below. — MartinHN

MartinHN MartinHN · Accepted Answer · 2014-02-11T15:52:38

You can't just read the location from the CLLocationManager. It needs to update its location before that property is assigned:

The value of this property is nil if no location data has ever been retrieved.

CLLocationManager SDK

You must implement the delegate method locationManager:didUpdateLocations:

And when that is called you can read the location property, or look at the locations argument:

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations {
    self.currentLocation = [locations firstObject];

    NSLog(@"Current Lat :%f",self.currentLocation.coordinate.latitude);
    NSLog(@"Current Long :%f",self.currentLocation.coordinate.longitude);

    [manager stopUpdatingLocation]
}

You can call [manager stopUpdatingLocation] when you get the first call, so it doesn't keep running.

CLLocationManager doesn't get location

1 Answers