Custom Annotation for Mapview Swift

Question

I looked at the posts for this and I still do not receive a custom pin....

Custom Annotation --> this includes setting my image

 import UIKit
 import MapKit

 class CustomPointAnnotation: MKPointAnnotation {
     var pinCustomImageName: UIImage!
 }

View Controller:

I want to return current location until a button is selected to drop pin

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    //current Location
    if !(annotation is CustomPointAnnotation) {
        return nil
    }
    let reuseIdentifier = "pin"
    var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier)
    if annotationView == nil {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
        annotationView!.canShowCallout = true
        
    } else {
        annotationView!.annotation = annotation
    }
    if let annotationView = annotationView {
        annotationView.image = UIImage(named: "Skyscraper")
        annotationView.canShowCallout = true
    }
   
    return annotationView
}

func addPin() {
    pointAnnotation = CustomPointAnnotation()
    pointAnnotation.pinCustomImageName = UIImage(named: "Skyscraper")
    pointAnnotation.coordinate = currentLocation.coordinate
    pointAnnotation.title = "First Building"
    pointAnnotation.subtitle = "Latitude: \(currentLocation.coordinate.latitude), \ 
     (currentLocation.coordinate.longitude)"
    mapView.addAnnotation(pointAnnotation)
}

Answer 1

There's nothing seriously wrong with the code. But there can be a couple of things that would cause problems, including:

1. Have you set the delegate (either in IB or programmatically) for the map view? If not, your mapView(_:viewFor:) will never be called. Add breakpoint or debugging print statement to confirm.

2. Have you confirmed that UIImage(named: "Skyscraper") is successfully retrieving an image? Make sure this is not returning nil .

---

Note, if only iOS 11 and later, you can simplify this code a bit. Since iOS 11, we no longer need for mapView(_:viewFor:) in simple scenarios like this. I would suggest putting the annotation view configuration code within the annotation view subclass, where it belongs, and avoid cluttering our view controller with a viewFor implementation.

So when you do get the current issue behind you, the recommended process is:

1. Define classes for your annotation and annotation view:

    class CustomAnnotation: MKPointAnnotation { var pinCustomImage: UIImage! }

   And

   class CustomAnnotationView: MKAnnotationView { override init(annotation: MKAnnotation?, reuseIdentifier: String?) { super.init(annotation: annotation, reuseIdentifier: reuseIdentifier) canShowCallout = true update(for: annotation) } override var annotation: MKAnnotation? { didSet { update(for: annotation) } } required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") } private func update(for annotation: MKAnnotation?) { image = (annotation as? CustomAnnotation)?.pinCustomImage } }

2. In viewDidLoad register this annotation view class:

    mapView.register(CustomAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)

3. Remove mapView(_:viewFor:) implementation.

Now when you add a CustomAnnotation to your map's list of annotations, it will be rendered correctly.

But I would suggest resolving your current problem first. There's no point in refining you implementation until these more basic issues are resolved.