Wrong cluster size when zooming out

[JustusvonBrandt]

I have implemented the clustering and it works fine, when I use the default MKAnnotationViews, so when I am not overriding the method mapView:ViewForAnnotation:
But I want to have different colored annotations for different sized clusters. I have implemented the method mapView:viewForAnnotation: as following:

    var annotationView = mapView.dequeueReusableAnnotationViewWithIdentifier("AnnotationView")
    if annotationView == nil {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "AnnotationView")
    }
    annotationView?.image = UIImage(named: "OneLocationAnnotationImage")!

    if annotation.isKindOfClass(CCHMapClusterAnnotation) {
        let clusterAnnotation = annotation as! CCHMapClusterAnnotation
        let count = clusterAnnotation.annotations.count
        if count == 1 {
            annotationView?.image = UIImage(named: "OneLocationAnnotationImage")!
        } else if count < 3 {
            annotationView?.image = UIImage(named: "LowDensityAnnotation")!
        } else if count < 5 {
            annotationView?.image = UIImage(named: "LowMediumDensityAnnotation")!
        } else if count < 7 {
            annotationView?.image = UIImage(named: "HighMediumDensityAnnotation")!
        } else {
            annotationView?.image = UIImage(named: "HighDensityAnnotation")!
        }

        return annotationView
    }
    return annotationView

When I now zoom in, the clustering works fine, but when I zoom out, the image is not returning to the one at the beginning, which should be the case. So the question is, if I am doing the right approach to get to the result I want?

[choefele]

The annotation views are recycled when zooming in and out. This means that the image needs to be updated in both mapView:viewForAnnotation: as well as mapClusterController:willReuseMapClusterAnnotation:. I suggest you have a look at MapViewController that comes with the iOS example – this class implements both methods to update the image displayed for the annotation views.

[JustusvonBrandt]

Thank you, that was the hint I needed :) Now the clustered annotations work properly!
The CCHMapClusterController is really well done and easy to implement, but there are two things I would change, because then it is even easier to use:
I had to search for the ClusterAnnotationView class in the example project, maybe you could include them in the Framework as "CCHClusterAnnotationView.h/m" and you could create an header importing all .h files, so that when you are using Swift you only have to import one file in the bridging header.