title: Pins have disappeared when using MKAnnotationView delegate
body: <p>My MKAnnotationView delegate method is been called as I can see my NSLog output. However the pins are not appearing on the map. Is there something I'm missing here?</p>
  
  <p>MapViewController.h</p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  #import &lt;MapKit/MapKit.h&gt;
  
  @interface MapViewController : UIViewController &lt;MKMapViewDelegate&gt;
  @property (weak, nonatomic) IBOutlet MKMapView *nearbyMapView;
  @end
  </code></pre>
  
  <p>MapViewController.m</p>
  
  <pre><code>#import "MapViewController.h"
  #import "AppDelegate.h"
  
  @interface MapViewController ()
  
  @end
  
  @implementation MapViewController
  AppDelegate *appDelegate;
  
  - (void)viewDidLoad
  {
      [super viewDidLoad];    
      appDelegate=[[UIApplication sharedApplication] delegate];
      CLLocationCoordinate2D center = CLLocationCoordinate2DMake(54.995184, -1.566699);
      MKCoordinateSpan span = MKCoordinateSpanMake(0.5, 0.5);
      MKCoordinateRegion regionToDisplay = MKCoordinateRegionMake(center, span);
      [self.nearbyMapView setRegion: regionToDisplay];
  
      for (int i = 0; i &lt; [[appDelegate offersFeeds] count]; i++) {
          CLGeocoder *geocoder = [[CLGeocoder alloc] init];
          NSString *plotAddress = [[[appDelegate offersFeeds] objectAtIndex:i] valueForKey:@"addressline"];
          NSString *plotTitle = [[[appDelegate offersFeeds] objectAtIndex:i] valueForKey:@"title"];
  
          [geocoder geocodeAddressString:plotAddress completionHandler:^(NSArray *placemarks, NSError *error) {
              if (placemarks &amp;&amp; placemarks.count &gt; 0)
              {
                  CLPlacemark *topResult = [placemarks objectAtIndex:0];
                  MKPlacemark *placemark = [[MKPlacemark alloc]initWithPlacemark:topResult];
  
                  MKPointAnnotation *pa = [[MKPointAnnotation alloc] init];
                  pa.coordinate = placemark.location.coordinate;
                  pa.title = plotTitle;
  
                  [self.nearbyMapView addAnnotation:pa];
              }
          }];
      }
  }
  
  - (void)didReceiveMemoryWarning {
      [super didReceiveMemoryWarning];
      // Dispose of any resources that can be recreated.
  }
  
  - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id &lt;MKAnnotation&gt;)annotation {
      MKAnnotationView *pinView = nil;
  
      static NSString *defaultPinID = @"identifier";
      pinView = (MKAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
      if ( pinView == nil ) {
          NSLog(@"Inside IF");
          pinView = [[MKAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:defaultPinID];
          pinView.enabled = YES;
          pinView.canShowCallout = YES;
          UIButton *btn = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];    
          //Accessoryview for the annotation view in ios.
          pinView.rightCalloutAccessoryView = btn;
      }
      else {
          pinView.annotation = annotation;
      }
      pinView.annotation = annotation;
      return pinView;
  }
  
  @end
  </code></pre>