如何拖动MKMapView拖动注释？(IOS)

Question

我有一个包含MKMapView的UIViewController.我通过以下代码在当前位置添加了注释:

import UIKit
import MapKit
class LocationViewController: UIViewController , MKMapViewDelegate ,CLLocationManagerDelegate {
    @IBOutlet weak var mapView: MKMapView!
    var locationManager: CLLocationManager!
    let regionRadius: CLLocationDistance = 1000
    var token: dispatch_once_t = 0
    override func viewDidLoad() {
        super.viewDidLoad()
        mapView.delegate = self
        locationManager = CLLocationManager()
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestWhenInUseAuthorization()
        locationManager.startUpdatingLocation()
    }

func centerMapOnLocation(location: CLLocation) {
    let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
        regionRadius * 2.0, regionRadius * 2.0)
    mapView.setRegion(coordinateRegion, animated: true)
}

func mapView(mapView: MKMapView, didUpdateUserLocation userLocation: MKUserLocation) {

    if ((userLocation.coordinate.latitude != 0.0) && (userLocation.coordinate.longitude != 0.0)) {
        dispatch_once(&token) {
            self.centerMapOnLocation(userLocation.location!)
            let annotation = MapPin(title: "This Location", locationName: "Test", discipline: "None", coordinate: userLocation.coordinate)
            mapView.addAnnotation(annotation)
        }
    }
}  

我希望在用户移动或拖动地图视图时进行注释移动.例如我当前的位置是New Albany,如果我拖动地图而不是注释将改变它在半空中浮动的阶段,直到我在Pontotoc顶部释放,因此注释指向我释放的位置.对于MapKit上的任何点击或好的教程,我将不胜感激.

Answer 1

首先,您必须返回注释的视图.你可以这样做:

func mapView(mapView: MKMapView, viewForAnnotation annotation: MKAnnotation) -> MKAnnotationView? {
    if annotation is MKUserLocation {
        return nil
    }

    let reuseId = "pin"
    var pinView = mapView.dequeueReusableAnnotationViewWithIdentifier(reuseId) as? MKPinAnnotationView
    if pinView == nil {
        pinView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: reuseId)
        pinView?.draggable = true
    }
    else {
        pinView?.annotation = annotation
    }

    return pinView
}

然后,一旦你在控制器中采用了MKMapViewDelegate协议,你就可以像这样拖动它来抓住一个引脚的坐标:

func mapView(mapView: MKMapView, annotationView view: MKAnnotationView, didChangeDragState newState: MKAnnotationViewDragState, fromOldState oldState: MKAnnotationViewDragState) {
    if newState == MKAnnotationViewDragState.Ending {
        let droppedAt = view.annotation?.coordinate
        print(droppedAt)
    }
}

另请参阅我的示例代码.

编辑

替代方案:

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
    // Remove all annotations
    self.mapView.removeAnnotations(mapView.annotations)

    // Add new annotation
    let annotation = MKPointAnnotation()
    annotation.coordinate = mapView.centerCoordinate
    annotation.title = "title"
    annotation.subtitle = "subtitle"
    self.mapView.addAnnotation(annotation)
}

别忘pinView?.animatesDrop = true了viewForAnnotation.