iOS- MKMapKit-How would I drop an annotation on the users location? - ios

Question

I have the users location on my app, but how would I drop an annotation on the current user location? Would I have to get the long & lat of the users location and drop an annotation that way? or how would I do it?

Answer 1

First import the necessary frameworks (CoreLocation and MapKit).
Then create the Objective-C NSObject class Annotation
Setup its .h:
#import <Foundation/Foundation.h>
#import <CoreLocation/CoreLocation.h>
#import <MapKit/MapKit.h>
#interface Annotation : NSObject <MKAnnotation>
#property (nonatomic) CLLocationCoordinate2D coordinate;
#property (nonatomic, copy) NSString *title;
#property (nonatomic, copy) NSString *subtitle;
#end
Setup its .m:
#import "Annotation.h"
#implementation Annotation
#synthesize coordinate, title, subtitle;
#end
Setup viewDidLoad
if ([CLLocationManager locationServicesEnabled]) {
locationManager = [[CLLocationManager alloc] init];
[locationManager setDelegate:self];
[locationManager setDesiredAccuracy: kCLLocationAccuracyBestForNavigation];
[locationManager startUpdatingLocation];
}
self.mapView.delegate = self;
Setup the didUpdateToLocation
// IMPORT ANNOTATION
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
[locationManager stopUpdatingLocation];
double miles = 3.10686;
double scalingFactor = ABS((cos(2 * M_PI * newLocation.coordinate.latitude / 360.0)));
MKCoordinateSpan span;
span.latitudeDelta = miles/69.0;
span.longitudeDelta = miles/(scalingFactor * 69.0);
MKCoordinateRegion region;
region.span = span;
region.center = newLocation.coordinate;
[self.mapView setRegion:region animated:YES];
Annotation *annot = [[Annotation alloc] init];
annot.coordinate = newLocation.coordinate;
[self.mapView addAnnotation:annot];
}

Answer 2

The simplest way is to set showsUserLocation to YES on your MKMapView and implement
- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation {
MKCoordinateRegion region = MKCoordinateRegionMake(userLocation.location.coordinate, MKCoordinateSpanMake(0.01, 0.01));
[mapView setRegion:region animated:NO];
}
in your MKMapViewDelegate to have the map view move to that location when the user's location has been found.
This will show a blue dot on the map view at the user's location like the Maps app does.