3
votes

I was trying to utilise map kit to show my current location using MKMapView and its delegate method, didUpdateUserLocation but when I zoom in and comes really close, I would see multiple pins. Then after some suggestions I realised, every time, the location is updated the pin is re-created. So, I took my add annotation code out of the delegate method.

Here is my code-

#import "MapViewController.h"
#import <MapKit/MapKit.h>
#import <CoreLocation/CoreLocation.h>


@interface MapViewController ()<MKMapViewDelegate, CLLocationManagerDelegate, UITextFieldDelegate> {
    MKPointAnnotation *myAnnotation;
}
@property (nonatomic, strong) IBOutlet MKMapView *mapView;
@property (nonatomic, strong) IBOutlet UITextField *searchTextField;

@property (strong, nonatomic) CLLocationManager *locationManager;

@end

@implementation MapViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.mapView.delegate=self;
    self.mapView.showsUserLocation=YES;

    self.locationManager = [[CLLocationManager alloc] init];
    self.locationManager.delegate = self;

    if ([self.locationManager respondsToSelector:@selector(requestWhenInUseAuthorization)]) {
        [self.locationManager requestWhenInUseAuthorization];
    }

    myAnnotation = [[MKPointAnnotation alloc]init];
    myAnnotation.coordinate = self.mapView.userLocation.coordinate;
    myAnnotation.title = @"Current Location";
    [self.mapView addAnnotation:myAnnotation];  
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];

}

#pragma mark-
#pragma mark- MapView Delegate


- (void)mapView:(MKMapView *)mapView didUpdateUserLocation:(MKUserLocation *)userLocation{

    MKCoordinateRegion region = MKCoordinateRegionMakeWithDistance(userLocation.coordinate, 800, 800);
    [self.mapView setRegion:[self.mapView regionThatFits:region] animated:YES];

}

@end

but now there is no pin.

3

3 Answers

3
votes

=> MKMapView automatically places an annotation of class MKUserLocation when you set mapView.showsUserLocation = YES:

You can replace the default view for this annotation to whatever default annotation view you want by doing this in mapView:viewForAnnotation:

- (MKAnnotationView *) mapView:(MKMapView *)theMapView viewForAnnotation:(id <MKAnnotation>)annotation {
    if ([annotation isKindOfClass:[MKUserLocation class]]) {
        // replace the following with code to generate and return custom user position annotation view
        return customAnnotationView;
    }

    //*** other code ***//
}
2
votes

Dear you need to put your myAnnotation code outside your delegate method "didUpdateUserLocation"

Note : you need to make Annotation in viewDidLoad then use didUpdateUserLocation for update your coordinate

0
votes

yes right if you do not want to display pin in mapview then keep out side of code or remove it whitch you have written in didUpdateUserLocation.