问题
I am trying to access some custom data I've setup in my custom annotation data when triggered by the rightCalloutAccessoryView. I am getting a compiler error as described below. Here's my custom MKAnnotation with a couple of extra variables - status & supplierdataindex
class CustomMapPinAnnotation : NSObject, MKAnnotation {
var coordinate: CLLocationCoordinate2D
var title: String
var subtitle: String
var status: Int
var supplierdataindex: Int
init(coordinate: CLLocationCoordinate2D, title: String, subtitle: String, status: Int, supplierdataindex: Int) {
self.coordinate = coordinate
self.title = title
self.subtitle = subtitle
self.status = status
self.supplierdataindex = supplierdataindex
}
} // CustomMapPinAnnotation
var myCustomMapPinAnnotationArray = [CustomMapPinAnnotation] ()
// I build an array and put that into myCustomMapPinAnnotationArray
...
// I add the annotations initially in viewDidLoad in the ViewController.swift via this call
theMapView.addAnnotations(myCustomMapPinAnnotationArray)
Everything works great in terms of the map and it's pins but now I want to access the custom parts of that myCustomMapPinAnnotation array, specifically the "status" and and "supplierdataindex" which will drive decisions for more detailed views. I am using the calloutAccessoryControlTapped to catch the click.
The problem is this compiler gives me an error below where I try to setup access that I thought would get me pointed to the custom data that should have been built into the annotation data I thought.
'MKAnnotation" is not convertible to 'CustomMapPinAnnotation'
func mapView(mapView: MKMapView!, annotationView: MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {
if control == annotationView.rightCalloutAccessoryView {
// This works and prints the data
println("Right Callout was pressed and title = \(annotationView.annotation.title)")
// This line yields a compiler error of: 'MKAnnotation is not convertible to 'CustomMapPinAnnotation'
var pinannotation : CustomMapPinAnnotation = annotationView.annotation
println("status was = \(myannotation.status)")
println("supplierdataindex was = \(myannotation.supplierdataindex)")
}
}
回答1:
You will have to typecast it to CustomMapPinAnnotation like this,
func mapView(mapView: MKMapView!, annotationView: MKAnnotationView, calloutAccessoryControlTapped control: UIControl) {
if control == annotationView.rightCalloutAccessoryView {
if let pinannotation = annotationView.annotation as? CustomMapPinAnnotation{
println("status was = \(pinannotation.status)")
println("supplierdataindex was = \(pinannotation.supplierdataindex)")
}
}
}
来源：https://stackoverflow.com/questions/25967783/problems-accessing-custom-mkannotation-data-via-rightcalloutaccessoryview