如何在Swift 2 [MapKit]中从地图中删除注释

Question

我可以使用“第一个”按钮在MapView上添加注释，但是我想添加一个新选项，该选项允许使用“第二个”按钮删除注释。 添加注释没有问题，但是我无法将其从地图视图中删除。 有人可以帮我吗？

这是我的代码：

class ViewController: UIViewController {

@IBOutlet weak var mapViewOutlet: MKMapView!

var lm = CLLocationManager()

override func viewDidLoad() {
    super.viewDidLoad()


    self.lm.requestAlwaysAuthorization()
    mapViewOutlet.showsUserLocation = true
    mapViewOutlet.userTrackingMode = MKUserTrackingMode.Follow

}

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

// HERE IS FUNCTION ADDANNOTATION

@IBAction func tagMyCar(sender: UIButton) {

    let coordinate = lm.location?.coordinate


    let CarCoordinates = CarAdnotaion(coordinate: coordinate!)

    mapViewOutlet.addAnnotation(CarCoordinates)

    let region = CLCircularRegion(center: coordinate!, radius: 5, identifier: "My Car")

    region.notifyOnEntry = true
    region.notifyOnExit = true

    lm.startMonitoringForRegion(region)

}

// HERE IS FUNCTION REMOVEANNOTATION

@IBAction func removeAnnotationfromMap(sender: AnyObject) {

    let region = CLCircularRegion(center: (lm.location?.coordinate)!, radius: 5, identifier: "Mój samochód")

    self.mapViewOutlet.removeAnnotation(CarAdnotaion(coordinate: (lm.location?.coordinate)!))

    lm.stopMonitoringForRegion(region)

}

}

Answer 1

我认为问题出在这里：

self.mapViewOutlet.removeAnnotation(CarAdnotaion(coordinate: (lm.location?.coordinate)!))

您将要删除在此语句中刚创建的注释。 相反，将let CarCoordinates向上移动（并在开头添加更合理的名称和小写字母）。 然后在该对象上调用removeAnnotation。

Answer 2

我有解决我的问题的方法。 有用！

import UIKit
import CoreLocation
import MapKit

class ViewController: UIViewController {

@IBOutlet weak var mapViewOutlet: MKMapView!

let lm = CLLocationManager()
var carAnnotation: CarAnnotationOnMap?
var region: CLCircularRegion?


override func viewDidLoad() {
    super.viewDidLoad()

    self.lm.requestAlwaysAuthorization()


    mapViewOutlet.userTrackingMode = MKUserTrackingMode.Follow
    mapViewOutlet.showsUserLocation = true

}

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

// ADD ANNOTATION ON MAP

@IBAction func tagMyCar(sender: UIButton) {

    let coordinates = lm.location?.coordinate
    carAnnotation = CarAnnotationOnMap(coordinates: coordinates!)

    region = CLCircularRegion(center: coordinates!, radius: 5, identifier: "My Zone")


    region!.notifyOnEntry = true
    region!.notifyOnExit = true
    self.lm.startMonitoringForRegion(region!)

    mapViewOutlet.addAnnotation(carAnnotation!)

}

// REMOVE ANNOTATION FROM MAP

@IBAction func removePinFromMyCar(sender: AnyObject) {
    self.lm.stopMonitoringForRegion(region!)
    mapViewOutlet.removeAnnotation(carAnnotation!)

}

}