Reload MKAnnotation in mapView - Swift - swift

Question

I have a problem, I have to constantly reload my view as I have to be able to view within this function the value of a UISlider that is constantly updated through an animation made through a function that manages the touch of a button. I noticed that when I open the map this slider value always remains fixed at the initial value, despite the latter having changed. How do I update the annotations? I have read on other posts about deleting and re-adding them:
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView?
{
if (annotation is MapEarthquakeAnnotation) {
let mapEqAnnotation = annotation as! MapEarthquakeAnnotation
var view: MKPinAnnotationView
print("MARIOCASH",Int(sliderTime.value))
if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: mapEqAnnotation.identifier) as? MKPinAnnotationView
{
// Recycle old view
dequeuedView.annotation = annotation
view = dequeuedView
}
else
{
// Create new view
view = MKPinAnnotationView(annotation: annotation, reuseIdentifier: mapEqAnnotation.identifier)
view.canShowCallout = true
view.pinTintColor = UIColor.brown
let infoButton = UIButton(type: .infoDark)
infoButton.addTarget(self, action: #selector(infoButtonClicked(_:)), for: .touchUpInside)
view.rightCalloutAccessoryView = infoButton
}
return view
}else if annotation is MapSeismometerAnnotation
{
if let annotation = annotation as? MapSeismometerAnnotation
{
var view: MKPinAnnotationView
/*
// Recycle old view
if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: annotation.identifier) as? MKPinAnnotationView
{
dequeuedView.annotation = annotation
view = dequeuedView
}
else
{ */
// Create new view
view = MKPinAnnotationView(annotation: annotation, reuseIdentifier: annotation.identifier)
view.canShowCallout = true
view.pinTintColor = UIColor.green
view.image = UIImage(named: "pin-verde")
if annotation.identifier == "redpin"
{
var count = 0
var c = 0.8 //valore iniziale dell'aplha per l'opacità del pin rosso
view.image = UIImage(named: "pin-rosso")
Timer.scheduledTimer(withTimeInterval: 1,repeats: true)
{t in //ogni secondo questo timer cambia il valore dell'alpha del pin che sta vibrando
view.alpha = CGFloat(c)
count += 1
c -= 0.15
if count == 5
{
t.invalidate()
}
}
}
return view
//}
}
return nil
}
return nil
}