How can I make an annotation like maps app has - ios

Question

I have an app with map and a lot of annotations that are made with custom image, and my problem is that when i drag the map or zoom the annotation shows another point (lat , lon).
So I was wondering because I see this bug in other applications too, is there any way to fix it (to be as the maps annotation that always shows the right lat and lon).
This is the code I use for annotation:
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
if annotation is MKUserLocation {
return nil
}
var reuseId = ""
if annotation is FBAnnotationCluster {
reuseId = "Cluster"
var clusterView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseId)
clusterView = FBAnnotationClusterView(annotation: annotation, reuseIdentifier: reuseId, configuration: FBAnnotationClusterViewConfiguration.default())
return clusterView
}else{
reuseId = "pin"
var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseId)
if annotationView == nil {
annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "pin")
annotationView!.image = UIImage(named: "locat.png")
}
else {
annotationView!.annotation = annotation
}
let cpa = annotation as! FBAnnotation
annotationView!.image = nil
let image = UIImage(named:cpa.nameImage)
annotationView!.image = image
return annotationView
}
}
If you have any question about what I'm asking or anything else please feel free to leave a comment.
Thanks in advance!
EDIT
I upload it an video showing my problem
EDIT2
And here is a video from maps that showing that their annotation is not losing its lat and lon.

Answer 1

Your problem is the MKAnnotationView.centerOffset you need to adjust this property in the func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView?
As is defined in MKAnnotationView Documentation
centerOffset Property The offset (in points) at which to display the
view.
var centerOffset: CGPoint
Discussion By default, the
center point of an annotation view is placed at the coordinate point
of the associated annotation. You can use this property to reposition
the annotation view as needed. This x and y offset values are measured
in points. Positive offset values move the annotation view down and to
the right, while negative values move it up and to the left.
Something like this
var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseId)
if annotationView == nil {
annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "pin")
annotationView!.image = UIImage(named: "locat.png")
//this is an example you must to get in account the form of your current view and what you want, I think your values are CGPoint(x: 0.5, y: 1)
annotationView?.centerOffset = CGPoint(x: 0, y: -((UIImage(named: "locat.png")?.size.height)!/2))
}
else {
annotationView!.annotation = annotation
}
Hope this helps you

Answer 2

You are not losing the lat long but your lat long are on center of your annotation image you have to change anchorPoint.
annotationView?.layer.anchorPoint = CGPoint(x: 0.5, y: 1.0)
in
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {