带有 MKMapKit 的 Swift GestureRecognizers - 放置引脚并拖动

Question

我正在尝试将多个UIGestureReconizers 与MKMapView 一起使用，用户可以在其上放置一个图钉并拖动它。它有一个callout。我在TabbarController 和NavigationController 中实现了这一点。我目前有：

1) PanGestureRecognizer 使标签栏和导航项目离开屏幕。这可以正常工作，而不会干扰平移地图。

2) 将TapGestureRecognizer 设置为一次点击可将 1) 中的两个项目动画化回到屏幕上。

3) 将TapGestureRecognizer 设置为两次点击允许底层MKMapView 缩放功能工作。此GestureRecognizer's delegate 已将gestureRecognizer.shouldRecognizeSimultaneouslyWithGestureRecognizer 设置为true

这些在viewDidLoad 中设置如下：

 // This sets up the pan gesture recognizer to hide the bars from the UI.
    let panRec: UIPanGestureRecognizer = UIPanGestureRecognizer(target: self, action: "didDragMap:")
    panRec.delegate = self
    mapView.addGestureRecognizer(panRec)

    // This sets up the tap gesture recognizer to un-hide the bars from the UI.
    let singleTap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "didTapMap:")
    singleTap.delegate = self
    singleTap.numberOfTapsRequired = 1
    singleTap.numberOfTouchesRequired = 1
    mapView.addGestureRecognizer(singleTap)

    // This sets up the double tap gesture recognizer to enable the zoom facility.
    // In order to pass double-taps to the underlying `MKMapView` the delegate for this recognizer (self) needs to return true from
    // gestureRecognizer.shouldRecognizeSimultaneouslyWithGestureRecognizer
    let doubleTap: UITapGestureRecognizer = UITapGestureRecognizer()
    doubleTap.numberOfTapsRequired = 2
    doubleTap.numberOfTouchesRequired = 1
    doubleTap.delegate = self
    mapView.addGestureRecognizer(doubleTap)

// This delays the single-tap recognizer slightly and ensures that it will NOT fire if there is a double-tap
    singleTap.requireGestureRecognizerToFail(doubleTap)

当我尝试实现UILongPressGestureRecognizer 以允许将图钉放置到地图上时，我的问题出现了。我正在尝试使用以下添加到viewDidLoad:

// This sets up the long tap to drop the pin.
    let longTap: UILongPressGestureRecognizer = UILongPressGestureRecognizer(target: self, action: "didLongTapMap:")
    longTap.delegate = self
    longTap.numberOfTapsRequired = 0
    longTap.minimumPressDuration = 0.5
    mapView.addGestureRecognizer(longTap)

这是我的操作方法：

func didLongTapMap(gestureRecognizer: UIGestureRecognizer) {
    // Get the spot that was tapped.
    let tapPoint: CGPoint = gestureRecognizer.locationInView(mapView)
    let touchMapCoordinate: CLLocationCoordinate2D = mapView.convertPoint(tapPoint, toCoordinateFromView: mapView)

    var viewAtBottomOfHierarchy: UIView = mapView.hitTest(tapPoint, withEvent: nil)
    if let viewAtBottom = viewAtBottomOfHierarchy as? MKPinAnnotationView {
        return
    } else {
        if .Began == gestureRecognizer.state {
            // Delete any existing annotations.
            if mapView.annotations.count != 0 {
                mapView.removeAnnotations(mapView.annotations)
            }

            annotation = MKPointAnnotation()
            annotation.coordinate = touchMapCoordinate

            mapView.addAnnotation(annotation)
            _isPinOnMap = true

            findAddressFromCoordinate(annotation.coordinate)
            updateLabels()
        }
    }
}

这确实允许在长按时放置一个大头针，并且单击一次将显示标注，但是如果没有足够快地开始拖动，则第二次轻按并拖动会导致第二个大头针掉落。第二个图钉落入前一个图钉悬停的空间中，用户可以拖动它，但新图钉的下落很笨拙且看起来不正确。

我正在尝试使用这条线：

if let viewAtBottom = viewAtBottomOfHierarchy as? MKPinAnnotationView {

将点击返回到MKMapView 并防止另一个引脚被丢弃，但即使此行上的断点显示 viewAtBottom 的类型为MapKit.MKPinAnnotationView，也不会调用返回。有什么想法我哪里出错了吗？

Answer 1

如果我理解正确，我想我可能会回答您的问题。 当一个大头针被放下然后拖动屏幕而不放置另一个大头针时，您会遇到问题，对吗？ 这是我的代码，我一直在做类似的事情，这似乎对我有用。 导入 UIKit 导入 MapKit 导入核心位置

class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {

    @IBOutlet var map: MKMapView!

    var manager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.


        let uilpgr = UILongPressGestureRecognizer(target: self, action: #selector(ViewController.longpress(gestureRecognizer:)))

        uilpgr.minimumPressDuration = 2

        map.addGestureRecognizer(uilpgr)

        if activePlace == -1 {

            manager.delegate = self
            manager.desiredAccuracy = kCLLocationAccuracyBest
            manager.requestWhenInUseAuthorization()
            manager.startUpdatingLocation()
            self.map.showsUserLocation = true

        } else {

            //GET PLACE DETAILS TO DISPLAY ON MAP

            if places.count > activePlace {

                if let name = places[activePlace]["name"]{

                    if let lat = places[activePlace]["lat"]{

                        if let lon = places[activePlace]["lon"]{

                            if let latitude = Double(lat) {

                                if let longitude = Double(lon) {

                                    let span = MKCoordinateSpan(latitudeDelta:  0.05, longitudeDelta: 0.05)

                                    let coordinate = CLLocationCoordinate2D(latitude: latitude, longitude: longitude)

                                    let region = MKCoordinateRegionMake(coordinate, span)

                                    self.map.setRegion(region, animated: true)

                                    let annotation = MKPointAnnotation()

                                    annotation.coordinate = coordinate

                                    annotation.title = name

                                    self.map.addAnnotation(annotation)

                                }

                            }

                        }

                    }

                }

            }

        }


    }


    func longpress(gestureRecognizer: UIGestureRecognizer) {

        if gestureRecognizer.state == UIGestureRecognizerState.began {

            let touchPoint = gestureRecognizer.location(in: self.map)

            let newCoordinate = self.map.convert(touchPoint, toCoordinateFrom: self.map)

            let location = CLLocation(latitude: newCoordinate.latitude, longitude: newCoordinate.longitude)

            var title = ""

            CLGeocoder().reverseGeocodeLocation(location, completionHandler: { (placemarks, error) in

                if error != nil {

                    print(error)

                } else {

                    if let placemark = placemarks?[0] {

                        if placemark.subThoroughfare != nil {

                            title += placemark.subThoroughfare! + " "

                        }

                        if placemark.thoroughfare != nil {

                            title += placemark.thoroughfare! + " "

                        }



                    }

                }

                if title == "" {

                    title = "Added \(NSDate())"

                }

                let annotation = MKPointAnnotation()

                annotation.coordinate = newCoordinate

                annotation.title = title

                self.map.addAnnotation(annotation)

                places.append(["name": title, "lat":String(newCoordinate.latitude), "lon":String(newCoordinate.longitude)])

                UserDefaults.standard.set(places, forKey: "places")

            })

        }

    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {

            let location = CLLocationCoordinate2D(latitude: locations[0].coordinate.latitude, longitude: locations[0].coordinate.longitude)

            let span = MKCoordinateSpan(latitudeDelta: 0.05, longitudeDelta: 0.05)

            let region = MKCoordinateRegion(center: location, span: span)

            self.map.setRegion(region, animated: true)

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


}

希望对您有所帮助，问题也可能是您的最小长按持续时间仅为 0.5。