didSelect for MKAnnotationView没有开火

Question

我有麻烦在MapView上选择自定义注释。我尝试了几种方法，没有成功：

• 使用MKMapViewDelegate的didSelect
• 使用添加到AnnotationView的UIButton
• 对ImageView使用UITapGestureRecognizer，它应该用于注释

您可以在下面的代码中找到所有这些方法：

override func viewDidLoad() {
    super.viewDidLoad()
    // some more initialization code

    for item in items {
        let annotation = IdentifiedMKPointAnnotation() // has only one additional property named "id"

        annotation.coordinate = CLLocationCoordinate2D(latitude: item.spots[0].latitude!, longitude: item.spots[0].longitude!)
        annotation.id = i

        self.mapView.addAnnotation(annotation)

        i += 1
    }
}


// MARK: - MapViewDelegate
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
    let item = self.items[(annotation as! IdentifiedMKPointAnnotation).id!]

    let annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: "")
    //annotationView.canShowCallout = false
    //annotationView.isEnabled = false

    let imageView = UIImageView()
    imageView.frame.size = CGSize(width: 40, height: 40)
    imageView.layer.cornerRadius = 20
    imageView.layer.masksToBounds = true
    imageView.af_setImage(withURL: URL(string: item.images.count > 0 ? item.images[0] : item.image!)!)
    imageView.contentMode = .scaleAspectFill

    //let gr = UIGestureRecognizer(target: self, action: #selector(annotationSelected(_:)))
    //imageView.addGestureRecognizer(gr)
    //imageView.isUserInteractionEnabled = true

    //let button = UIButton()
    //button.frame.size = CGSize(width: 40, height: 40)
    //button.setImage(#imageLiteral(resourceName: "play_arrow"), for: .normal)
    //button.addTarget(self, action: #selector(annotationSelected(_:)), for: .touchUpInside)

    annotationView.addSubview(imageView)
    //annotationView.addSubview(button)

    return annotationView
}

func mapView(_ mapView: MKMapView, didSelect view: MKAnnotationView) {
    performSegue(withIdentifier: "showDetail", sender: self.items[(view.annotation as! IdentifiedMKPointAnnotation).id!])

    view.setSelected(false, animated: false)
}

func annotationSelected(_ sender: UIImageView) {
    performSegue(withIdentifier: "showDetail", sender: self.items[((sender.superview as! MKAnnotationView).annotation as! IdentifiedMKPointAnnotation).id!])
}

任何想法，为什么行动不是/没有解雇？

Answer 1

如果注释的title为空，则不调用didSelect委托。请尝试以下代码。

let annotation = IdentifiedMKPointAnnotation()
annotation.title = "title"

Answer 2

刚刚找到基于以下帖子的解决方案：https://stackoverflow.com/a/28671680/6010489

设置注释视图的高度和宽度就足够了：

annotationView.frame.size.height = 40
annotationView.frame.size.width = 40

Answer 3

出于某种原因，当在Storyboard（Xcode 10.2，Swift 5.0）中设置了mapView的委托时，我遇到了同样的问题。所以这不起作用：

但是，当我删除连接并在代码中执行它，它工作正常：

@IBOutlet weak var mapView: MKMapView!

override func viewDidLoad() {
    super.viewDidLoad()

    mapView.delegate = self
}

可能是一个Swift 5 bug？ Storyboard解决方案适用于Objective-C。