MKMapView 在 Swift 中缩小地图时没有聚类注释

Question

在复制我的任务之前，请阅读全文。 我在我的应用程序中使用 MkMapKit，现在我必须在缩小地图时显示集群中的人，到目前为止，我已经使用 Apple 的默认集群类从 this answer 对他们进行了编号。现在我不知道如何添加并显示它们所有一个圆圈，我知道它应该与半径有关，但我不知道我该怎么做，在下面分享我的代码，我希望任何帮助赞赏。谢谢 还展示了我所做的事情：

这是我的 UserAnnotationClass

class UserAnnotation: NSObject, MKAnnotation {

    let title: String?
    let locationName: String
    let discipline: String
    let coordinate: CLLocationCoordinate2D

    let userProfile: UserProfile!
    let index: Int!
    let memberAnnotations: [UserProfile]!
    init(userProfile: UserProfile, at index: Int) {

        self.title = userProfile.fullName
        self.locationName = (userProfile.locationAddress != nil) ? userProfile.locationAddress : ""
        let userProfilePicture: String = (userProfile.profilePicture == nil || userProfile.profilePicture == "") ? "" : userProfile.profilePicture

        self.discipline = userProfilePicture

       // print("\(userProfile.fullName) \(userProfile.location.dist)")

        if (userProfile.isMapVisibility == true) {
            self.coordinate = CLLocationCoordinate2D(latitude: userProfile.location.lat, longitude: userProfile.location.lon)
        } else {
            self.coordinate = CLLocationCoordinate2D(latitude: 0.0, longitude: 0.0)
        }
        memberAnnotations = [UserProfile]()
        memberAnnotations.append(userProfile)
        self.userProfile = userProfile
        self.index = index

        super.init()
    }

    var subtitle: String? {
        return locationName
    }

    // pinTintColor for disciplines: Sculpture, Plaque, Mural, Monument, other
    var markerTintColor: UIColor  {
        switch discipline {
        case "Monument":
            return .red
        case "Mural":
            return .cyan
        case "Plaque":
            return .blue
        case "Sculpture":
            return .purple
        default:
            return .clear
        }
    }

    // Annotation right callout accessory opens this mapItem in Maps app
    func mapItem() -> MKMapItem {
        let addressDict = [CNPostalAddressStreetKey: subtitle!]
        let placemark = MKPlacemark(coordinate: coordinate, addressDictionary: addressDict)
        let mapItem = MKMapItem(placemark: placemark)
        mapItem.name = title


        return mapItem
    }
}

这是 CLusterViewClass 我用来使它们聚集在一起的。

class ClusterView: MKAnnotationView {


    override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
        let hitView = super.hitTest(point, with: event)
        if (hitView != nil)
        {

            if (hitView?.isKind(of: UIButton.self))! {

                let sender: UIButton = hitView as! UIButton

                sender.sendActions(for: .touchUpInside)

            }
            else {

                self.superview?.bringSubviewToFront(self)
            }
        }
        return hitView
    }
    override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
        let rect = self.bounds
        var isInside: Bool = rect.contains(point)
        if(!isInside)
        {
            for view in self.subviews
            {
                isInside = view.frame.contains(point)
                if isInside
                {
                    break
                }
            }
        }
        return isInside
    }
    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        displayPriority = .defaultHigh
        collisionMode = .circle
        centerOffset = CGPoint(x: 0, y: -10) // Offset center point to animate better with marker annotations
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var annotation: MKAnnotation? {
        willSet {

            canShowCallout = false

            if let cluster = newValue as? UserAnnotation {
                let renderer = UIGraphicsImageRenderer(size: CGSize(width: 40, height: 40))
                let count = cluster.memberAnnotations.count
                let uniCount = cluster.memberAnnotations.filter { member -> Bool in
                    //Log("Bool  \(member) , \(member.isMapVisibility == false) ????")

                    return member.isMapVisibility == true
                }.count
                //Log("COUNTS \(count) , \(uniCount) ❤️")
                image = renderer.image { _ in
                    // Fill full circle with tricycle color
                    if uniCount > 0 {

                        AppTheme.blueColor.setFill()
                        UIBezierPath(ovalIn: CGRect(x: 0, y: 0, width: 40, height: 40)).fill()

                        // Fill inner circle with white color
                        UIColor.white.setFill()
                        UIBezierPath(ovalIn: CGRect(x: 8, y: 8, width: 24, height: 24)).fill()

                        // Finally draw count text vertically and horizontally centered
                        let attributes = [ NSAttributedString.Key.foregroundColor: UIColor.black,
                                           NSAttributedString.Key.font: UIFont.boldSystemFont(ofSize: 20)]
                        //let text = "\(count)"
                        let text = "4"
                        let size = text.size(withAttributes: attributes)
                        let rect = CGRect(x: 20 - size.width / 2, y: 20 - size.height / 2, width: size.width, height: size.height)
                        text.draw(in: rect, withAttributes: attributes)
                    }
                }
            }
        }
    }

}

这些是我的一些 MapKit 函数

extension FeedsViewController: MKMapViewDelegate {

    //   1
      func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
        guard let annotation = annotation as? UserAnnotation else { return nil }
        // 2
        let identifier = "marker"
        if #available(iOS 11.0, *) {
            var view: ClusterView

            if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier)
                as? ClusterView { // 3
                dequeuedView.annotation = annotation
                view = dequeuedView
            } else {
                // 4
                view = ClusterView(annotation: annotation, reuseIdentifier: identifier)
            }
            return view
        } else {
            // Fallback on earlier versions

            return nil
        }

      }
    func mapView(_ mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
//        let zoomWidth = mapView.visibleMapRect.size.width
//        let zoomFactor = Int(log2(zoomWidth))
//        print("...REGION DID CHANGE: ZOOM FACTOR \(zoomFactor)")
        let centralLocation = CLLocation(latitude: mapView.centerCoordinate.latitude, longitude:  mapView.centerCoordinate.longitude)

        Log("???? Radius - \(self.getRadius(centralLocation: centralLocation))")


    }
    func getRadius(centralLocation: CLLocation) -> Double{
        let topCentralLat:Double = centralLocation.coordinate.latitude -  mapView.region.span.latitudeDelta/2
        let topCentralLocation = CLLocation(latitude: topCentralLat, longitude: centralLocation.coordinate.longitude)
        let radius = centralLocation.distance(from: topCentralLocation)
        return radius / 1000.0 // to convert radius to meters
    }
    func mapView(_ mapView: MKMapView,
                 didSelect view: MKAnnotationView)
    {
        // 1
        if view.annotation is MKUserLocation
        {
            // Don't proceed with custom callout
            return
        }
        // 2
        let annotation = view.annotation as! UserAnnotation

        let detailAnnotationView: UserDetailAnnotationView = UserDetailAnnotationView(frame: CGRect(x: 0, y: 0, width: 320, height: 74))

        let url = (annotation.discipline == "") ? nil : URL(string: annotation.discipline)!
        let range = 0.0..<0.9
        if annotation.userProfile.location.dist != nil {
            if range.contains(annotation.userProfile.location.dist) {
                let kMeters = Measurement(value: annotation.userProfile.location.dist, unit: UnitLength.kilometers)
                let meters = kMeters.converted(to: UnitLength.meters)
                detailAnnotationView.distancelbl.text = "\(String(describing: round(Double(meters.value)))) m Away"

            } else {
                detailAnnotationView.distancelbl.text = "\(String(describing: round(annotation.userProfile.location.dist))) Km Away"
            }
        }

        detailAnnotationView.set(Title: annotation.title!, imageUrl: url) { [weak self] (sender) in
            guard let self = self else { return }
            if self.isOpenChat {

                self.isOpenChat = false

                if annotation.userProfile.channel != "" {

                    self.appDelegate.pubNubAddPushNotifications([annotation.userProfile.channel]) { (status) in

                        print(status.description)
                    }

                    let chatViewController: ChatViewController = self.storyboard?.instantiateViewController(withIdentifier: "ChatViewController") as! ChatViewController

                    chatViewController.userProfile = annotation.userProfile
                    chatViewController.loginUserProfile = self.loginUserProfile
                    self.navigationController?.pushViewController(chatViewController, animated: true)
                }
            }

        }

        detailAnnotationView.center = CGPoint(x: view.bounds.size.width / 2, y: -detailAnnotationView.bounds.size.height*0.52)

        view.addSubview(detailAnnotationView)

        mapView.setCenter((view.annotation?.coordinate)!, animated: true)

//        let calloutView = views?[0] as! CustomCalloutView
//        calloutView.starbucksName.text = starbucksAnnotation.name
//        calloutView.starbucksAddress.text = starbucksAnnotation.address
//        calloutView.starbucksPhone.text = starbucksAnnotation.phone
//        calloutView.starbucksImage.image = starbucksAnnotation.image
//        let button = UIButton(frame: calloutView.starbucksPhone.frame)
//        button.addTarget(self, action: #selector(ViewController.callPhoneNumber(sender:)), for: .touchUpInside)
//        calloutView.addSubview(button)
//        // 3
//        calloutView.center = CGPoint(x: view.bounds.size.width / 2, y: -calloutView.bounds.size.height*0.52)
//        view.addSubview(calloutView)
//        mapView.setCenter((view.annotation?.coordinate)!, animated: true)
    }

    func mapView(_ mapView: MKMapView, didDeselect view: MKAnnotationView) {
        if #available(iOS 11.0, *) {
            if view.isKind(of: ClusterView.self)
            {
                for subview in view.subviews
                {
                    subview.removeFromSuperview()
                }
            }
        } else {
            // Fallback on earlier versions
        }
    }

    func mapView(_ mapView: MKMapView, annotationView view: MKAnnotationView,
                 calloutAccessoryControlTapped control: UIControl) {
//        let location = view.annotation as! UserAnnotation
//        let launchOptions = [MKLaunchOptionsDirectionsModeKey:
//            MKLaunchOptionsDirectionsModeDriving]
//        location.mapItem().openInMaps(launchOptions: launchOptions)
    }
}

这就是我设置 mapView 的方式......

fileprivate func setupMapsLayout() {

    if self.userAnnotationList.count > 0 {
    // HereMap
        self.mapView.removeAnnotations(self.userAnnotationList)
    }

    self.mapView.delegate = self
    //    mapView.register(ArtworkMarkerView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
    if #available(iOS 11.0, *) {
        // HereMap
        //self.mapView.register(UserAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
        mapView.register(ClusterView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultClusterAnnotationViewReuseIdentifier)
    } else {
        // Fallback on earlier versions
    }

    self.loadInitialData()

    self.mapView.addAnnotations(self.userAnnotationList)
    //self.mapView.topCenterCoordinate()
}

Answer 1

好的，iOS 11 及更高版本的解决方案相当简单。您有两个注释视图，一个用于您自己的注释，一个用于注释集群。你的主注解视图只需要在初始化和annotation属性改变时指定clusteringIdentifier：

class UserAnnotationView: MKMarkerAnnotationView {
    static let preferredClusteringIdentifier = Bundle.main.bundleIdentifier! + ".UserAnnotationView"

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        clusteringIdentifier = UserAnnotationView.preferredClusteringIdentifier
        collisionMode = .circle
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var annotation: MKAnnotation? {
        willSet {
            clusteringIdentifier = UserAnnotationView.preferredClusteringIdentifier
        }
    }
}

当更新 annotation 属性时，您的集群注释视图应该只更新其图像：

class UserClusterAnnotationView: MKAnnotationView {
    static let preferredClusteringIdentifier = Bundle.main.bundleIdentifier! + ".UserClusterAnnotationView"

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        collisionMode = .circle
        updateImage()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var annotation: MKAnnotation? { didSet { updateImage() } }

    private func updateImage() {
        if let clusterAnnotation = annotation as? MKClusterAnnotation {
            self.image = image(count: clusterAnnotation.memberAnnotations.count)
        } else {
            self.image = image(count: 1)
        }
    }

    func image(count: Int) -> UIImage {
        let bounds = CGRect(origin: .zero, size: CGSize(width: 40, height: 40))

        let renderer = UIGraphicsImageRenderer(bounds: bounds)
        return renderer.image { _ in
            // Fill full circle with tricycle color
            AppTheme.blueColor.setFill()
            UIBezierPath(ovalIn: bounds).fill()

            // Fill inner circle with white color
            UIColor.white.setFill()
            UIBezierPath(ovalIn: bounds.insetBy(dx: 8, dy: 8)).fill()

            // Finally draw count text vertically and horizontally centered
            let attributes: [NSAttributedString.Key: Any] = [
                .foregroundColor: UIColor.black,
                .font: UIFont.boldSystemFont(ofSize: 20)
            ]

            let text = "\(count)"
            let size = text.size(withAttributes: attributes)
            let origin = CGPoint(x: bounds.midX - size.width / 2, y: bounds.midY - size.height / 2)
            let rect = CGRect(origin: origin, size: size)
            text.draw(in: rect, withAttributes: attributes)
        }
    }
}

然后，您所要做的就是注册您的课程：

mapView.register(UserAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
mapView.register(UserClusterAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultClusterAnnotationViewReuseIdentifier)

不需要（也不需要）实现mapView(_:viewFor:)。但是上面的结果（在你缩小和缩小时显示默认动画）：

现在，很明显，您可以随意修改UserAnnotationView。 （您的问题并未说明标准的单用户注释视图会是什么样子）。但是通过设置它的clusteringIdentifier 并注册一个MKMapViewDefaultClusterAnnotationViewReuseIdentifier，你可以在iOS 11 及更高版本中相当容易地进行集群。

如果你真的想让集群注解视图看起来像标准的注解视图，你可以为两者注册相同的注解视图类：

mapView.register(UserClusterAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultAnnotationViewReuseIdentifier)
mapView.register(UserClusterAnnotationView.self, forAnnotationViewWithReuseIdentifier: MKMapViewDefaultClusterAnnotationViewReuseIdentifier)

但是你必须给集群注解视图赋予我们之前给标准注解视图相同的 clusteringIdentifier：

class UserClusterAnnotationView: MKAnnotationView {
    static let preferredClusteringIdentifier = Bundle.main.bundleIdentifier! + ".UserClusterAnnotationView"

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        clusteringIdentifier = UserClusterAnnotationView.preferredClusteringIdentifier
        collisionMode = .circle
        updateImage()
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override var annotation: MKAnnotation? {
        didSet {
            clusteringIdentifier = UserClusterAnnotationView.preferredClusteringIdentifier
            updateImage()
        }
    }

    private func updateImage() {
        if let clusterAnnotation = annotation as? MKClusterAnnotation {
            self.image = image(count: clusterAnnotation.memberAnnotations.count)
        } else {
            self.image = image(count: 1)
        }
    }

    func image(count: Int) -> UIImage {
        let bounds = CGRect(origin: .zero, size: CGSize(width: 40, height: 40))

        let renderer = UIGraphicsImageRenderer(bounds: bounds)
        return renderer.image { _ in
            // Fill full circle with tricycle color
            AppTheme.blueColor.setFill()
            UIBezierPath(ovalIn: bounds).fill()

            // Fill inner circle with white color
            UIColor.white.setFill()
            UIBezierPath(ovalIn: bounds.insetBy(dx: 8, dy: 8)).fill()

            // Finally draw count text vertically and horizontally centered
            let attributes: [NSAttributedString.Key: Any] = [
                .foregroundColor: UIColor.black,
                .font: UIFont.boldSystemFont(ofSize: 20)
            ]

            let text = "\(count)"
            let size = text.size(withAttributes: attributes)
            let origin = CGPoint(x: bounds.midX - size.width / 2, y: bounds.midY - size.height / 2)
            let rect = CGRect(origin: origin, size: size)
            text.draw(in: rect, withAttributes: attributes)
        }
    }
}

产生：

就个人而言，我认为这有点令人困惑，但如果这就是你想要的，那是实现它的一种方法。

---

现在，如果您确实需要支持 11 之前的 iOS 版本并且想要集群，那么您必须自己完成所有这些集群逻辑（或找到第三方库来完成）。 Apple 在 WWDC 2011 Visualizing Information Geographically with MapKit 中展示了如何做到这一点。他们采用的概念是将可见地图划分为一个网格，如果特定网格中有多个注释，他们将删除它们并添加一个“集群”注释。它们说明了您甚至可以如何在视觉上动画化注释进出集群的移动，因此用户可以在放大和缩小时了解正在发生的事情。这是您深入研究的一个很好的起点。

这很重要，所以我会仔细考虑是否要自己实现它。我要么放弃 11 之前的 iOS 版本，要么找到第三方实现（question you reference 有很多例子）。