Question

我的mapView有一个自定义注释。我最初使用一些数据在其上设置坐标，标题（例如“第一个标题”），subTitle（例如“第一个地址”），userId和距离（例如0米）属性。我将其添加到mapView和数组中以备后用。一切正常，将其显示在mapView上，然后按一下，标注将显示初始数据。

我后来得到更新，该标注的位置已更改。我遍历数组，并使用坐标，标题（例如“新标题”），subTitle（例如“新地址”）和距离（例如100米）属性的新数据更新标注。我还将标注从原始位置动画化为新位置。动画效果很好，标注从A点移到B点。

问题是，当我点击注释时，标注上会显示旧数据，而不是新数据。

我使用calloutAccessoryControlTapped来推送新的vc。当我在其中放置断点时，自定义引脚将包含所有新数据。该标注似乎发生了错误。

我该如何解决？

我不想从mapView中清除所有注释，所以这不是一个选择。我呼叫mapView.removeAnnotation(customPin)和mapView.addAnnotation(customPin)来解决该销钉的问题，但是当销钉被拔出并重新添加到地图上并且当它动画到它的新位置时，它会闪烁。 / p>

自定义注释

class CustomPin: NSObject, MKAnnotation {

    @objc dynamic var coordinate: CLLocationCoordinate2D
    var title: String?
    var subtitle: String?
    var userId: String?
    var distance: CLLocationDistance?

    init(coordinate: CLLocationCoordinate2D, title: String, subtitle: String, userId: String, distance: CLLocationDistance?) {

        self.coordinate = coordinate
        self.title = title
        self.subtitle = subtitle
        self.userId = userId
        self.distance = distance

        super.init()
    }
}

第一次使用初始数据设置注释

firstFunctionThatGetsTheInitialLocation(origLat, origLon) {

   let firstCoordinate = CLLocationCoordinate2DMake(origLat, origLon)   

   let distanceInMeters: CLLocationDistance = self.center.distance(from: anotherUsersLocation)

   let customPin = CustomPin(coordinate: firstCoordinate, title: "first title", subtitle: "first address", userId: "12345", distance: distance)

    DispatchQueue.main.async { [weak self] in

      self?.mapView.addAnnotation(customPin)

      self?.arrOfPins.append(customPin)
    }
}

第二次使用新数据设置注释

secondFunctionThatGetsTheNewLocation(newCoordinate: CLLocationCoordinate2D, newDistance: CLLocationDistance) {

    for pin in customPins {

        pin.title = "second title" // ** updates but the callout doesn't reflect it
        pin.subTitle = "second address" // ** updates but the callout doesn't reflect it
        pin.distance = newDistance // ** updates but the callout doesn't reflect it

       // calling these gives me the new data but the annotation blinks and moves really fast to it's new location
       // mapView.removeAnnotation(pin)
       // mapView.addAnnotation(pin)

        UIView.animate(withDuration: 1) {
            pin.coordinate = newCoordinate // this updates and animates to the new location with no problem
        }
    }
}

MapView viewFor注释

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

    if annotation.isKind(of: MKUserLocation.self) { return nil }

    guard let annotation = annotation as? CustomPin else { return nil }

    let reuseIdentifier = "CustomPin"

    var annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: reuseIdentifier)

    if annotationView == nil {
        annotationView = MKAnnotationView(annotation: annotation, reuseIdentifier: reuseIdentifier)
        annotationView?.canShowCallout = true
        annotationView?.calloutOffset = CGPoint(x: -5, y: 5)

        annotationView?.rightCalloutAccessoryView = UIButton(type: .detailDisclosure)

        annotationView?.image = UIImage(named: "chevronImage")

    } else {
        annotationView?.annotation = annotation
    }

    annotationView?.detailCalloutAccessoryView = nil
    annotationView?.detailCalloutAccessoryView = createCallOutWithDataFrom(customPin: annotation)

    return annotationView
}

创建用于标注的UIView

func createCallOutWithDataFrom(customPin: CustomPin) -> UIView {

    let titleText = customPin.title
    let subTitleText = customPin.subTitle
    let distanceText = subTitle.distance // gets converted to a string

    // 1. create a UIView
    // 2. create some labels and add the text from the title, subTitle, and distance and add them as subViews to the UIView
    // 3. return the UIView
}

Answer 1

有几个问题：

您需要对要观察的任何属性使用@objc dynamic限定符。标准标注在title和subtitle上执行Key-Value Observation（KVO）。（并且注释视图观察到coordinate的变化。）

如果您要观察userid和distance，则还必须制作@objc dynamic。请注意，您必须将distance设为非可选，以使其可观察：

var distance: CLLocationDistance

所以：

class CustomAnnotation: NSObject, MKAnnotation {
    // standard MKAnnotation properties

    @objc dynamic var coordinate: CLLocationCoordinate2D
    @objc dynamic var title: String?
    @objc dynamic var subtitle: String?

    // additional custom properties

    @objc dynamic var userId: String
    @objc dynamic var distance: CLLocationDistance

    init(coordinate: CLLocationCoordinate2D, title: String, subtitle: String, userId: String, distance: CLLocationDistance) {
        self.userId = userId
        self.distance = distance
        self.coordinate = coordinate
        self.title = title
        self.subtitle = subtitle

        super.init()
    }
}

就像我说的那样，标准标注遵循title和subtitle。虽然必须使注释属性可观察，但是如果要构建自己的detailCalloutAccessoryView，则必须做自己的KVO：

class CustomAnnotationView: MKMarkerAnnotationView {
    private let customClusteringIdentifier = "..."

    override init(annotation: MKAnnotation?, reuseIdentifier: String?) {
        super.init(annotation: annotation, reuseIdentifier: reuseIdentifier)
        canShowCallout = true
        detailCalloutAccessoryView = createCallOutWithDataFrom(customAnnotation: annotation as? CustomAnnotation)
        clusteringIdentifier = customClusteringIdentifier
    }

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

    deinit {
        removeAnyObservers()
    }

    override var annotation: MKAnnotation? {
        didSet {
            removeAnyObservers()
            clusteringIdentifier = customClusteringIdentifier
            if let customAnnotation = annotation as? CustomAnnotation {
                updateAndAddObservers(for: customAnnotation)
            }
        }
    }

    private var subtitleObserver: NSKeyValueObservation?
    private var userObserver: NSKeyValueObservation?
    private var distanceObserver: NSKeyValueObservation?

    private let subtitleLabel: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()

    private let userLabel: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()

    private let distanceLabel: UILabel = {
        let label = UILabel()
        label.translatesAutoresizingMaskIntoConstraints = false
        return label
    }()
}

private extension CustomAnnotationView {
    func updateAndAddObservers(for customAnnotation: CustomAnnotation) {
        subtitleLabel.text = customAnnotation.subtitle
        subtitleObserver = customAnnotation.observe(\.subtitle) { [weak self] customAnnotation, _ in
            self?.subtitleLabel.text = customAnnotation.subtitle
        }

        userLabel.text = customAnnotation.userId
        userObserver = customAnnotation.observe(\.userId) { [weak self] customAnnotation, _ in
            self?.userLabel.text = customAnnotation.userId
        }

        distanceLabel.text = "\(customAnnotation.distance) meters"
        distanceObserver = customAnnotation.observe(\.distance) { [weak self] customAnnotation, _ in
            self?.distanceLabel.text = "\(customAnnotation.distance) meters"
        }
    }

    func removeAnyObservers() {
        subtitleObserver = nil
        userObserver = nil
        distanceObserver = nil
    }

    func createCallOutWithDataFrom(customAnnotation: CustomAnnotation?) -> UIView {
        let view = UIView()
        view.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(subtitleLabel)
        view.addSubview(userLabel)
        view.addSubview(distanceLabel)

        NSLayoutConstraint.activate([
            subtitleLabel.topAnchor.constraint(equalTo: view.topAnchor),
            subtitleLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            subtitleLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            subtitleLabel.bottomAnchor.constraint(equalTo: userLabel.topAnchor),

            userLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            userLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            userLabel.bottomAnchor.constraint(equalTo: distanceLabel.topAnchor),

            distanceLabel.leadingAnchor.constraint(equalTo: view.leadingAnchor),
            distanceLabel.trailingAnchor.constraint(equalTo: view.trailingAnchor),
            distanceLabel.bottomAnchor.constraint(equalTo: view.bottomAnchor)
        ])

        if let customAnnotation = customAnnotation {
            updateAndAddObservers(for: customAnnotation)
        }

        return view
    }
}

产生：

Swift-detailCalloutAccessoryView不更新数据

1 个答案: