Swift Mapkit - 远离用户位置

Question

我想显示用户位置和周围区域，但我也想允许用户在该区域周围平移。现在，如果我尝试在地图上的其他位置滚动，它会自动将我带回以用户为中心的基本区域。我该如何阻止这个？我想在中心显示用户的初始视图，但我也希望能够滚动。在此先感谢你们，你们太有帮助了！

导入 UIKit 导入 MapKit 导入核心位置

类 ViewControllerMain: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {

@IBOutlet weak var mapView: MKMapView!

var locationManager:CLLocationManager!

override func viewDidLoad() {
    super.viewDidLoad()
    locationManager = CLLocationManager()
    locationManager.requestWhenInUseAuthorization()
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.delegate = self
    locationManager.startUpdatingLocation()
    mapView.showsUserLocation = true
    mapView.delegate = self

    let longPress = UILongPressGestureRecognizer(target: self, action: "action:")
    longPress.minimumPressDuration = 1.0
    mapView.addGestureRecognizer(longPress)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
    let regionToZoom = MKCoordinateRegionMake(manager.location.coordinate, MKCoordinateSpanMake(0.01, 0.01))
    mapView.setRegion(regionToZoom, animated: true)
}

Answer 1

您在 didUpdateLocations 中的代码正在重置该区域。你有两个选择。

1. 无论您是否已设置第一个位置，都存储在 ivar 中。只有当你没有这样做时，你才设置区域。

2. 设置一个运行 15 秒的计时器。如果地图被用户移动，则重置计时器。当计时器到期时，您可以重新定位到用户位置。

这将保持地图以用户为中心，但将使他们能够平移一点以获取一些上下文。

This answer shows how to do it in Objective-C

Answer 2

locationManager.stopUpdatingLocation();

这就是你在 locationManager 结束时所需要的一切，如果你还在寻找

Answer 3

This thread had a good example 在 Swift 和 Obj C 中。如果您使用 Swift，请务必查看我链接到的答案的评论。

设置完成后，在 didUpdateLocations 中使用控制流，以便仅在用户未触摸地图时才重新居中用户的位置。

以我的完整代码为例：

@IBOutlet weak var theMap: MKMapView!

// ... 


// This var and the three following functions are used to tell if the map moves because of the user. 
// This is used in the control flow in didUpdateLocations

private var mapChangedFromUserInteraction = false


private func mapViewRegionDidChangeFromUserInteraction() -> Bool {
    let view: UIView = self.theMap.subviews[0] as UIView
    //  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 changed map region
        println("user changed map region")


    }
}

func mapView(mapView: MKMapView, regionDidChangeAnimated animated: Bool) {
    if (mapChangedFromUserInteraction) {
        // user changed map region

        println("user changed map region")


    }
}

// This function is called each time the user moves.  
func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {




// Use Control Flow: if the user has moved the map, then don't re-center.
// NOTE: this is using 'mapChangedFromUserInteraction' from above. 

    if mapChangedFromUserInteraction == true {

        // do nothing, because the user has moved the map.

    }

    else {

        // update on location to re-center on the user.

        // set X and Y distances for the span (zoom). This is very zoomed in.
        let spanX = 0.0005
        let spanY = 0.0005

        // Create a region using the user's location, and the zoo. 
        var newRegion = MKCoordinateRegion(center: theMap.userLocation.coordinate, span: MKCoordinateSpanMake(spanX, spanY))

        // set the map to the new region
        theMap.setRegion(newRegion, animated: true)

        }

}