Is it possible to customize cluster image in iOS 11?

问题

I'm using iOS 11 new APIs and I have been successful in making cluster appear. Now, I'm trying to change cluster image providing a custom image. Since I created this custom annotation view:

    class PlaceView: MKAnnotationView {
        override var annotation: MKAnnotation? {
            willSet {
                guard let place = newValue as? Place else {return}
                clusteringIdentifier = Place.type
                image = place.image
            }
    }

I tried to add this line inside willSet block:

cluster?.image = UIImage(named: "Cluster")

but it didn't work.

What am I missing? Can anyone point me in the right direction?

回答1:

You should check to see if the annotation is of type MKClusterAnnotation. If it is you can then use the memberAnnotations property to access the member annotations. In your case, for example, you could say:

override var annotation: MKAnnotation?
{
    willSet
    {
        if let cluster = newValue as? MKClusterAnnotation { 
            image = UIImage(named: "Cluster")
        } else {
            // set image for non cluster
        }
    }
}

For more information see WWDC 2017 What's New with MapKit.

来源：https://stackoverflow.com/questions/47100598/is-it-possible-to-customize-cluster-image-in-ios-11