Swift - setting different images from array to annotation pins - ios

Question

I wonder how to set different images to annotation pins on mapview. The difference between the following questions
viewForAnnotation confusion and customizing the pinColor iteratively
Swift different images for Annotation
is that my array of images is generated dynamically with regard to server response. There is no fixed size of the array, so switch/case construction is not a good idea. Moreover, I'm not sure how to apply the solution with custom class aforementioned in topic above. I'm aware that it would be better to post a comment to one of the questions asked before, but unfortunately I'm too rookie at the moment to do that(too few points).
This is the for loop performed inside functions that shows map:
for var r=0;r<arrayOfRestaurants.count;r++
{
var summonRestaurant:NSDictionary = arrayOfRestaurants[r] as NSDictionary
var nearbyRestaurant = Restaurant(nearbyRestaurants:summonRestaurant)
var latRestaurant=(nearbyRestaurant.latitude as NSString).doubleValue
var longRestaurant=(nearbyRestaurant.longitude as NSString).doubleValue
var locationOfRestaurant = CLLocationCoordinate2D(
latitude: latRestaurant as CLLocationDegrees, longitude: longRestaurant as CLLocationDegrees)
var lunchArray: NSArray = nearbyRestaurant.lunch as NSArray
var annotation = MKPointAnnotation()
annotation.setCoordinate(locationOfRestaurant)
annotation.title = nearbyRestaurant.name + " " + nearbyRestaurant.distance + " km"
map.addAnnotation(annotation)
}
And here is viewForAnnotation delegate method(quite identical to the method used in aforementioned threads):
func mapView(map: MKMapView!,
viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
if annotation is MKUserLocation {
//return nil so map view draws "blue dot" for standard user location
return nil
}
let reuseId = "pin"
var pinView = map.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
if pinView == nil {
pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
pinView!.canShowCallout = true
pinView!.animatesDrop = true
pinView!.pinColor = .Purple
pinView!.image = globalImageArray[0]
}
else {
pinView!.annotation = annotation
}
return pinView
}
As you can see, I assigned a certain image to pinView which is globalImageArray[0], but I look for a solution that let me iterate over the globalImageArray and assign a certain image to each pin.
I'd be glad to receive any help, thanks in advance!

Answer 1

First, you need to create your own class that adopts the MKAnnotation protocol for your annotations -
class RestaurantAnnotation : NSObject, MKAnnotation {
var coordinate: CLLocationCoordinate2D
var title: String
var subtitle: String
var image: UIImage?
init(coordinate: CLLocationCoordinate2D, title: String, subtitle: String) {
self.coordinate = coordinate
self.title = title
self.subtitle = subtitle
}
}
Then, use instances of this class when you add the annotation and set the image -
for var r=0;r<arrayOfRestaurants.count;r++
{
var summonRestaurant:NSDictionary = arrayOfRestaurants[r] as NSDictionary
var nearbyRestaurant = Restaurant(nearbyRestaurants:summonRestaurant)
var latRestaurant=(nearbyRestaurant.latitude as NSString).doubleValue
var longRestaurant=(nearbyRestaurant.longitude as NSString).doubleValue
let locationOfRestaurant = CLLocationCoordinate2D(
latitude: latRestaurant as CLLocationDegrees, longitude: longRestaurant as CLLocationDegrees)
var lunchArray: NSArray = nearbyRestaurant.lunch as NSArray
let title = nearbyRestaurant.name + " " + nearbyRestaurant.distance +" km"
var annotation = RestaurantAnnotation(coordinate, title:title, subtitle:"")
annotation.image = globalImageArray[r]
map.addAnnotation(annotation)
}
Now, in your view for annotation you can access the image -
func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
if !(annotation is RestaurantAnnotation) {
return nil
}
let reuseId = "restaurant"
var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
if anView == nil {
anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
anView.canShowCallout = true
}
else {
anView.annotation = annotation
}
let restaurantAnnotation = annotation as RestaurantAnnotation
if (restaurantAnnotation.image != nil) {
anView.image = restaurantAnnotation.image!
anView.image.layer.setCornerRadius(8.0)
anView.image.layer.clipsToBounds=true
}
else {
// Perhaps set some default image
}
return anView
}