Add thumbnail to an MKPinAnnotation

Question

I have this Custom MKPinAnnotation to which I need to add an image(Like a thumbnail). I should also be able to open the image fullscreen by tapping it. What is the best way to go around doing this?

Answer 1

A couple of thoughts.

1. If you don't want a pin on the map, but rather some custom image, you can set your map's delegate and then write a viewForAnnotation that does something like:

   - (MKAnnotationView *)mapView:(MKMapView *)mapView viewForAnnotation:(id <MKAnnotation>)annotation
   {
       if ([annotation isKindOfClass:[CustomAnnotation class]])
       {
           static NSString * const identifier = @"MyCustomAnnotation";
   
           // if you need to access your custom properties to your custom annotation, create a reference of the appropriate type:
   
           CustomAnnotation *customAnnotation = annotation;
   
           // try to dequeue an annotationView
   
           MKAnnotationView* annotationView = [mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
   
           if (annotationView)
           {
               // if we found one, update its annotation appropriately
   
               annotationView.annotation = annotation;
           }
           else
           {
               // otherwise, let's create one
   
               annotationView = [[MKAnnotationView alloc] initWithAnnotation:annotation
                                                             reuseIdentifier:identifier];
   
               annotationView.image = [UIImage imageNamed:@"myimage"];
   
               // if you want a callout with a "disclosure" button on it
   
               annotationView.canShowCallout = YES;
               annotationView.rightCalloutAccessoryView = [UIButton buttonWithType:UIButtonTypeDetailDisclosure];
   
               // If you want, if you're using QuartzCore.framework, you can add
               // visual flourishes to your annotation view:
               //
               // [annotationView.layer setShadowColor:[UIColor blackColor].CGColor];
               // [annotationView.layer setShadowOpacity:1.0f];
               // [annotationView.layer setShadowRadius:5.0f];
               // [annotationView.layer setShadowOffset:CGSizeMake(0, 0)];
               // [annotationView setBackgroundColor:[UIColor whiteColor]];
           }
   
           return annotationView;
       }
   
       return nil;
   }
   

2. If you do it with the standard callout (as shown above), you can then tell the map what you want to do when the user taps on the callout's disclosure button:

   - (void)mapView:(MKMapView *)mapView annotationView:(MKAnnotationView *)view calloutAccessoryControlTapped:(UIControl *)control
   {
       if (![view.annotation isKindOfClass:[CustomAnnotation class]])
           return;
   
       // do whatever you want to do to go to your next view
   }
   

3. If you really want to bypass the callout with its disclosure button, but rather to go directly to another view controller when you tap on the annotation view, you would:

   • Set canShowCallout to NO in your viewForAnnotation; and

   • Write your own didSelectAnnotationView

For more information, see Annotating Maps in the Location Awareness Programming Guide.