I'm trying to fade my annotations in through animation, so I create them with an alpha of 0, and then animate their alpha to 1 in didAddAnnotation. Sometimes I'm only adding a few annotations, subtracting others, but right now EVERY annotation on screen is being faded out/in when ANY are added rather than the expected behavior, which would be that only the recently added pins would fade to 1.
- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views{
for (MKAnnotationView *view in views){
if (view.alpha ==0){
[UIView animateWithDuration:.5 animations:^{
view.alpha = 1;
}];
}
}
For animating the annotations as its added, you can use this subclass of MKAnnotationView
class AnnotationView: MKAnnotationView {
override var annotation: MKAnnotation? {
didSet {
UIView.animate(withDuration: 0.5) { self.alpha = 1.0 }
}
}
override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
self.alpha = 0
}
override func prepareForReuse() {
super.prepareForReuse()
self.alpha = 0.0
}
}
Usage:
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
if let view = mapView.dequeueReusableAnnotationView(withIdentifier: "annot") as? AnnotationView {
return view
}
return AnnotationView(annotation: annotation, reuseIdentifier: "annot")
}