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Question

我对两个代码块之间的链接有疑问，这可能会改变注释图像。我是 swift 新手，所以我很难在 mapView 上找到它。我在函数中给出了一个代码，用于在运行时打印一个字符串，但该字符串没有显示在 NSLog 中。这是否意味着该功能根本没有运行？对于我哪里出错的任何建议，我将不胜感激。谢谢

class ViewController2: UIViewController {

@IBOutlet var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()

//Location for first Pin
let locationOne = CLLocationCoordinate2DMake(-47.016945, 167.852095)

//Location for map centering
let locationNZ = CLLocationCoordinate2DMake(-43.937462, 170.507813)
let span = MKCoordinateSpanMake(9, 9)
let region = MKCoordinateRegion(center: locationNZ, span: span)
mapView.setRegion(region, animated: true)

//Create annotation one
let annotation = MKPointAnnotation()
annotation.coordinate = locationOne
annotation.subtitle = "Park"
annotation.title = "Rakiura National Park"

//Add annotation to the map
mapView.addAnnotation(annotation)}

override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()}




func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {

print("func")
guard !annotation.isKind(of: MKUserLocation.self) else {
return nil}

let annotationIdentifier = "AnnotationIdentifier"

var annotationView: MKAnnotationView?
if let dequeuedAnnotationView = mapView.dequeueReusableAnnotationView(withIdentifier: annotationIdentifier) {
annotationView = dequeuedAnnotationView
annotationView?.annotation = annotation}
 else {

let av = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationIdentifier)
av.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)
annotationView = av}

if let annotationView = annotationView {
annotationView.canShowCallout = true
annotationView.image = UIImage(named: "mapIcon.png")}

return annotationView}}

Answer 1

听起来你可能有我忘了设置委托，所以我的委托从来没有被称为问题;当您的委托方法没有触发时，这应该始终是您所怀疑的。试试

mapView.delegate = self