Ios 如何检测在Swift和更新缩放中移动的地图视图

我正在尝试在Swift 2中设置地图的最小缩放级别。我找不到任何关于如何限制地图被放大太远的文档。我决定尝试监视地图的移动（如拖动或缩放），然后将

MKZoomScale

设置回最小值

我找到的大部分关于

regionDidChangeAnimated

的答案都是在Objective C中，我不知道，我很难将它们转换成Swift

我尝试实现@hEADcRASH的答案：，但当地图在模拟器中移动时，它不会触发并向控制台打印任何内容

谁能告诉我我做错了什么？我是Swift新手，所以这可能是个小错误。另外，请告诉我是否有一种轻量级方法可以解决限制地图缩放级别的问题。我担心“运动监视器”会使贴图动画的速度减慢一点。谢谢你的帮助

这是我的视图控制器。 导入UIKit 导入解析 导入地图套件

class SearchRadiusViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {

@IBOutlet weak var map: MKMapView!

@IBOutlet weak var menuBtn: UIBarButtonItem!

var locationManager = CLLocationManager()

override func viewDidLoad() {
    super.viewDidLoad()

    //menu button control
    if self.revealViewController() != nil {
        menuBtn.target = self.revealViewController()
        menuBtn.action = "revealToggle:"
        self.view.addGestureRecognizer(self.revealViewController().panGestureRecognizer())
    }

    //user location
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestWhenInUseAuthorization()
    locationManager.startUpdatingLocation()


}

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


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

    //set map
    let location:CLLocationCoordinate2D = manager.location!.coordinate
    let latitude = location.latitude
    let longitude = location.longitude
    let latDelta:CLLocationDegrees = 0.1
    let longDelta:CLLocationDegrees = 0.1
    let span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, longDelta)
    let maplocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude)
    let region:MKCoordinateRegion = MKCoordinateRegionMake(maplocation, span)
    map.setRegion(region, animated: true)

    //stop updating location, only need user location once to position map.
    manager.stopUpdatingLocation()

}

//Attempt to monitor for map movement based on hEADcRASH's answer.
private var mapChangedFromUserInteraction = false

private func mapViewRegionDidChangeFromUserInteraction() -> Bool {
    let view = self.map.subviews[0]
    //  Look through gesture recognizers to determine whether this region change is from user interaction
    if let gestureRecognizers = view.gestureRecognizers {
        for recognizer in gestureRecognizers {
            if( recognizer.state == UIGestureRecognizerState.Began || recognizer.state == UIGestureRecognizerState.Ended ) {
                return true
            }
        }
    }
    return false
}

func mapView(mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
    print("yes")
    mapChangedFromUserInteraction = mapViewRegionDidChangeFromUserInteraction()
    if (mapChangedFromUserInteraction) {
        // user changed map region
        print("user changed map in WILL")
    }
}

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
            print("yes ddd")
    if (mapChangedFromUserInteraction) {
        // user changed map region
        print("user changed map in Did")
    }
}
}

---

在回顾并结合了许多其他问题/答案以及@lorenzoliveto的帮助后，我已经在Swift中使用了它。如果有更好/更轻量级的方法来实现同样的目标，请留下评论

我在viewDidLoad函数中添加了

self.map.delegate=self

下面是我如何监控地图移动的代码，当用户放大“太远”且地图宽度小于2英里时，我使用

mapView.setRegion

缩小地图

private var mapChangedFromUserInteraction = false

private func mapViewRegionDidChangeFromUserInteraction() -> Bool {
    let view = self.map.subviews[0]
    //  Look through gesture recognizers to determine whether this region change is from user interaction
    if let gestureRecognizers = view.gestureRecognizers {
        for recognizer in gestureRecognizers {
            if( recognizer.state == UIGestureRecognizerState.Began || recognizer.state == UIGestureRecognizerState.Ended ) {
                return true
            }
        }
    }
    return false
}

func mapView(mapView: MKMapView, regionWillChangeAnimated animated: Bool) {
    mapChangedFromUserInteraction = mapViewRegionDidChangeFromUserInteraction()
    if (mapChangedFromUserInteraction) {
        // user will change map region
        print("user WILL change map.")

        // calculate the width of the map in miles.
        let mRect: MKMapRect = mapView.visibleMapRect
        let eastMapPoint = MKMapPointMake(MKMapRectGetMinX(mRect), MKMapRectGetMidY(mRect))
        let westMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), MKMapRectGetMidY(mRect))
        let currentDistWideInMeters = MKMetersBetweenMapPoints(eastMapPoint, westMapPoint)
        let milesWide = currentDistWideInMeters / 1609.34  // number of meters in a mile
        print(milesWide)
        print("^miles wide")

        // check if user zoomed in too far and zoom them out.
        if milesWide < 2.0 {
            var region:MKCoordinateRegion = mapView.region
            var span:MKCoordinateSpan = mapView.region.span
            span.latitudeDelta = 0.04
            span.longitudeDelta = 0.04
            region.span = span;
            mapView.setRegion(region, animated: true)
            print("map zoomed back out")
        }

    }
}

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
    if (mapChangedFromUserInteraction) {
        // user changed map region
        print("user CHANGED map.")
        print(mapView.region.span.latitudeDelta)
        print(mapView.region.span.longitudeDelta)

        // calculate the width of the map in miles.
        let mRect: MKMapRect = mapView.visibleMapRect
        let eastMapPoint = MKMapPointMake(MKMapRectGetMinX(mRect), MKMapRectGetMidY(mRect))
        let westMapPoint = MKMapPointMake(MKMapRectGetMaxX(mRect), MKMapRectGetMidY(mRect))
        let currentDistWideInMeters = MKMetersBetweenMapPoints(eastMapPoint, westMapPoint)
        let milesWide = currentDistWideInMeters / 1609.34  // number of meters in a mile
        print(milesWide)
        print("^miles wide")

        // check if user zoomed in too far and zoom them out.
        if milesWide < 2.0 {
            var region:MKCoordinateRegion = mapView.region
            var span:MKCoordinateSpan = mapView.region.span
            span.latitudeDelta = 0.04
            span.longitudeDelta = 0.04
            region.span = span;
            mapView.setRegion(region, animated: true)
            print("map zoomed back out")
        }
    }

---

是否在情节提要中设置地图视图的代理？如果没有，您应该在viewDidLoad方法中添加self.map.delegate=self。谢谢@lorenzoliveto，将

self.map.delegate=self

添加到viewDidLoad中是可行的。mapViewRegionDidChangeAnimated正在工作！您对设置最大缩放级别的最佳方法有何看法？我是否应该观察地图移动/缩放并重置地图缩放？是的，我认为这是您唯一的选择。regionWillChangeAnimated:在滚动期间调用多次，RegionIDChangeAnimated:仅在滚动后调用一次。尝试在两者中添加重置代码，看看性能是如何受到影响的。我正在寻找如何检测映射更改，发现了这个问题。似乎我只需要

func mapViewRegionDidChangeFromUserInteraction（）

谢谢分享！

dispatch_async(dispatch_get_main_queue(), {
   var region:MKCoordinateRegion = mapView.region
   var span:MKCoordinateSpan = mapView.region.span
   span.latitudeDelta = 0.04
   span.longitudeDelta = 0.04
   region.span = span;
   mapView.setRegion(region, animated: true)
   print("map zoomed back out")
})