Objective C - Have only one pin at a time?

Question

I have 2 different set of pins on top of a map view. One pin appears first and it's the user location, then when you search for a location in the search bar multiple pins appear depending on the location. I want to have one pin showing at a time. Once you search for the location the user's location pin should disappear, and once you select one of the multiple pins you searched the others should disappear.

Here's my code:

 #import "UbicacionVC.h"
 #import "SWRevealViewController.h"
 #import <MapKit/Mapkit.h>
 #import "Location.h"


 @interface UbicacionVC ()

 @end

 @implementation UbicacionVC
 @synthesize mapView;

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view.
     [self inicializarComponentes];
     self.mapView.delegate = self;
     self.searchBar.delegate = self;
 }



 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 - (void)inicializarComponentes {
     [self.btnContinuar.layer setCornerRadius:20.0f];
     [self.btnCancelar.layer setCornerRadius:20.0f];

     ////
     UITapGestureRecognizer *gestureMenu = [[UITapGestureRecognizer                                                   alloc] init];
     [gestureMenu addTarget:self.revealViewController                                              action:@selector(revealToggle:)];
     [gestureMenu setCancelsTouchesInView:NO];
     [self.btnLeftMenu addGestureRecognizer:gestureMenu];

     [self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];
////
locationManager = [[CLLocationManager alloc] init];
locationManager.delegate = self;
locationManager.distanceFilter = kCLDistanceFilterNone;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
[locationManager startUpdatingLocation];

if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0)
    [self->locationManager requestWhenInUseAuthorization];

[locationManager startUpdatingLocation];



 }



 - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation {
     NSLog(@"OldLocation %f %f", oldLocation.coordinate.latitude, oldLocation.coordinate.longitude);
     NSLog(@"NewLocation %f %f", newLocation.coordinate.latitude, newLocation.coordinate.longitude);
     CLLocationDegrees lat = newLocation.coordinate.latitude;
     CLLocationDegrees lon = newLocation.coordinate.longitude;
     CLLocation * location = [[CLLocation alloc]initWithLatitude:lat longitude:lon];
     self.viewRegion =      MKCoordinateRegionMakeWithDistance(location.coordinate, 500, 500);
[self.mapView setRegion:self.viewRegion];


 }


 -(void)localSearch:(NSString*)searchString{

     [self.mapView setRegion:self.viewRegion];

     MKLocalSearchRequest * request = [[MKLocalSearchRequest alloc] init];
     request.naturalLanguageQuery = [searchString lowercaseString];
     request.region = self.viewRegion;

     MKLocalSearch* search = [[MKLocalSearch alloc] initWithRequest:request];
     [search startWithCompletionHandler:^(MKLocalSearchResponse *response, NSError *error) {

         if([response.mapItems count] == 0){
        NSLog(@"No matches \n");
    }
         else{
             for(MKMapItem * item in response.mapItems){
                 Location * pin = [[Location alloc] initWith:item.placemark.title andSubtitle:item.phoneNumber andCoordinate:item.placemark.coordinate andImageName:@"" andURL:item.url.absoluteString];
                 [self.mapView addAnnotation:pin];


        }
    }

}];

 }

 #pragma mark UISearchBarDelegate

 -(void)searchBarSearchButtonClicked:(UISearchBar *)searchBar{

     [searchBar resignFirstResponder];
     [self.mapView removeAnnotations:[self.mapView annotations]];
     [self localSearch:searchBar.text];

 }

 #pragma mark MKMapViewDelegate

 -(MKAnnotationView*)mapView:(MKMapView*)sender viewForAnnotation:          (id<MKAnnotation>)annotation{

     static NSString* identifier = @"reusablePin";

     MKAnnotationView * aView = [sender dequeueReusableAnnotationViewWithIdentifier:identifier];
     if(!aView){

         aView = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier];
         aView.canShowCallout = YES;
     }

     aView.annotation = annotation;
     return aView;
 }


 - (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
 {

          NSLog(@"%@",view.annotation.title);

          NSLog(@"%@",view.annotation.subtitle);


 }

Answer 1

I want to have one pin showing at a time.

How about break; in for loop?

for(MKMapItem * item in response.mapItems){
    Location * pin = [[Location alloc] initWith:item.placemark.title andSubtitle:item.phoneNumber andCoordinate:item.placemark.coordinate andImageName:@"" andURL:item.url.absoluteString];
    [self.mapView addAnnotation:pin];

    // one pin showed
    break;
}

Once you search for the location the user's location pin should disappear, and once you select one of the multiple pins you searched the others should disappear.

You can use didSelectAnnotationView method.

- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view
{
  // once you select one of the multiple pins, the others should disappear.
  for (MKPointAnnotation *annotation in mapView.annotations) {
    if (view.annotation != annotation) {
        [mapView removeAnnotation:annotation];
        NSLog(@"yes!!");
    }
  }
}