Question

I have a few questions about CoreLocation and GPS.

First, what method in core location is used to continually get the users current coordinates? And at what interval should these be retrieved?

Second, should these coordinates be pushed into a NSMutableArray each time they are received, so that the array of coordinates will represent the users path?

Thanks, just wanting to get started getting me mind around this.

Answer 1

A very abbreviated version:

First, adopt the <CLLocationManagerDelegate> protocol in your .h, and #import <CoreLocation/CoreLocation.h>.

Then in .m go:

- (void)viewDidLoad {
    locationManager = [[CLLocationManager alloc] init];
    locationManager.delegate = self;
    locationManager.desiredAccuracy = kCLLocationAccuracyBest;
    [locationManager startUpdatingLocation];
}


-(void)locationManager:(CLLocationManager *)manager
   didUpdateToLocation:(CLLocation *)newLocation
          fromLocation:(CLLocation *)oldLocation
{
    CLLocationCoordinate2D here =  newLocation.coordinate;
    NSLog(@"%f  %f ", here.latitude, here.longitude);
}

Your -(void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation method will get pinged every time Core Location has something to say to you, which should happen every few seconds. those CLLocation objects contain info about accuracy, so you can screen for good points in that method.

Be sure to call [locationManager stopUpdatingLocation] and then [locationManager release] at some point!

Good luck finding yourself!