Zoom in to current location on map - ios

Question

I want to show the current location of the user on the map and zoom on to it.
I tried as follows:
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
NSLog(#"Init MapViewController");
[self initMap];
}
return self;
}
-(void) initMap
{
_mapView = [[MKMapView alloc] initWithFrame:self.view.frame];
_mapView.delegate = self;
_mapView.showsUserLocation = YES;
[self.view addSubview:_mapView];
CLLocationCoordinate2D currentLocation;
currentLocation.latitude = _mapView.userLocation.coordinate.latitude;
currentLocation.longitude= _mapView.userLocation.coordinate.longitude;
MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(currentLocation, 0.5*METERS_PER_MILE, 0.5*METERS_PER_MILE);
[_mapView setRegion:viewRegion animated:YES];
}
Then in the simulator it shows a location in the sea. I set the location to London in the simulator.

Answer 1

Just do This:
#property (strong, nonatomic) CLLocationManager *locationManager;
In viewdidload:
self.locationManager = [[CLLocationManager alloc] init] ;
self.locationManager.delegate = (id)self;
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation ;
[self.locationManager setDistanceFilter:10.0f] ;
[self.locationManager startUpdatingLocation];
And in your location manager
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation
fromLocation:(CLLocation *)oldLocation
{
[self.locationManager stopUpdatingLocation];
CLLocationCoordinate2D zoomLocation;
zoomLocation.latitude = YourMapView.userLocation.location.coordinate.latitude;
zoomLocation.longitude= YourMapView.userLocation.location.coordinate.longitude;
// 2
MKCoordinateRegion viewRegion = MKCoordinateRegionMakeWithDistance(zoomLocation, 0.5*1609.344, 0.5*1609.344);
// 3
[YourMapView setRegion:viewRegion animated:YES];
}

Answer 2

I needed to listen to changes for the user location. Because in the view didload the location isn't known.
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
MKCoordinateRegion region;
region.center = self.mapView.userLocation.coordinate;
MKCoordinateSpan span;
span.latitudeDelta = 1; // Change these values to change the zoom
span.longitudeDelta = 1;
region.span = span;
[self.mapView setRegion:region animated:YES];
}
and this in the viewdidload:
[self.mapView.userLocation addObserver:self
forKeyPath:#"location"
options:(NSKeyValueObservingOptionNew|NSKeyValueObservingOptionOld)
context:nil];