How to change MKAnnotation Color using Swift? - ios

Question

I have MKAnnotations set up on a map, but I would like to change the color of the annotations for different scenario's. Is there a way to change the color of the annotation?
Here is my code below, how would I implement the color change?
override func viewDidAppear(animated: Bool) {
var annotationQuery = PFQuery(className: "Post")
currentLoc = PFGeoPoint(location: MapViewLocationManager.location)
//annotationQuery.whereKey("Location", nearGeoPoint: currentLoc, withinMiles: 10)
annotationQuery.whereKeyExists("Location")
annotationQuery.findObjectsInBackgroundWithBlock {
(points, error) -> Void in
if error == nil {
// The find succeeded.
println("Successful query for annotations")
// Do something with the found objects
let myPosts = points as! [PFObject]
for post in myPosts {
let point = post["Location"] as! PFGeoPoint
let annotation = MKPointAnnotation()
annotation.coordinate = CLLocationCoordinate2DMake(point.latitude, point.longitude)
annotation.title = post["title"] as! String!
annotation.subtitle = post["username"] as! String!
self.mapView.addAnnotation(annotation)
}
} else {
// Log details of the failure
println("Error: \(error)")
}
}

Answer 1

You can use custom images for annotation view or use predefined MKPinAnnotationView with pinColor. But pinColors limited to Red, Green and Purple.
Some example:
import UIKit
import MapKit
class Annotation: NSObject, MKAnnotation
{
var coordinate: CLLocationCoordinate2D = CLLocationCoordinate2D(latitude: 0.0, longitude: 0.0)
var custom_image: Bool = true
var color: MKPinAnnotationColor = MKPinAnnotationColor.Purple
}
class ViewController: UIViewController, MKMapViewDelegate {
#IBOutlet weak var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
self.mapView.delegate = self;
let annotation = Annotation.new()
mapView.addAnnotation(annotation)
let annotation2 = Annotation.new()
annotation2.coordinate = CLLocationCoordinate2D(latitude: 0.0, longitude: 1.0)
annotation2.custom_image = false
mapView.addAnnotation(annotation2)
let annotation3 = Annotation.new()
annotation3.coordinate = CLLocationCoordinate2D(latitude: 1.0, longitude: 0.0)
annotation3.custom_image = false
annotation3.color = MKPinAnnotationColor.Green
mapView.addAnnotation(annotation3)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
func mapView(mapView: MKMapView!, viewForAnnotation annotation: MKAnnotation!) -> MKAnnotationView! {
if (annotation is MKUserLocation) {
return nil
}
var anView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId)
if anView == nil {
if let anAnnotation = annotation as? Annotation {
if anAnnotation.custom_image {
let reuseId = "custom_image"
anView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
anView.image = UIImage(named:"custom_image")
}
else {
let reuseId = "pin"
let pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
pinView.pinColor = anAnnotation.color
anView = pinView
}
}
anView.canShowCallout = false
}
else {
anView.annotation = annotation
}
return anView
}
}
Update:
Set delegate for mapView in viewDidLoad

Answer 2

You have to set it in the viewForAnnotation method.
In this tutorial is quite well explained how doing it.