swift - MKMapView 不是在 Swift 中缩小 map 时的聚类注释

Question

在复制我的问题之前，请阅读整篇文章。我在我的应用程序中使用 MkMapKit，现在我必须在缩小 map 时显示集群中的人，到目前为止，我已经使用 from this answer 实现了对他们进行编号。使用 Apple 的默认集群类。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相关但我不知道我该怎么做，在下面分享我的代码，我希望有任何帮助赞赏。谢谢还展示了我所做的事情的图片:

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
    }
}

这是我用来使它们聚类的 CLusterViewClass。

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 View ，一个用于您自己的注释，一个用于注释集群。您的主注释 View 只需在初始化时以及 annotation 属性更改时指定 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
        }
    }
}

并且您的集群注释 View 应该在其 annotation 属性更新时更新其图像:

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类(class):

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

不需要(也不需要)mapView(_:viewFor:) 实现。但是上面的结果(在缩小和返回时显示默认动画):

现在，显然，您可以随意修改 UserAnnotationView。 (您的问题没有说明标准的单用户注释 View 是什么样的)。但是通过设置它的 clusteringIdentifier 并注册一个 MKMapViewDefaultClusterAnnotationViewReuseIdentifier，您可以在 iOS 11 及更高版本中相当轻松地进行集群。

如果你真的想让集群注释 View 看起来像标准注释 View ，你可以为两者注册相同的注释 View 类:

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

但是您必须为集群注释 View 提供我们之前为标准注释 View 提供的相同 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:

就我个人而言，我认为这有点令人困惑，但如果这是您的目标，那么这是实现它的一种方式。

---

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(或寻找第三方库来完成)。 Apple 在 WWDC 2011 中展示了如何做到这一点 Visualizing Information Geographically with MapKit .他们采用的概念是将可见 map 划分为网格，如果在特定网格内有多个注释，他们会删除它们并添加一个“集群”注释。它们还说明了您甚至可以如何以视觉方式动画化注解移入和移出群集，以便用户可以了解在放大和缩小时发生了什么。当您深入研究时，这是一个很好的起点。

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 iOS 11 之前的版本，要么寻找第三方实现(question you reference 有很多示例)。