ios MapKit 缩放到用户当前位置

MapKit zoom to user current location

提问by Mc.Lover

I am trying to simply show user's location on the map, but I need to when app launches, the map should zoom to current location ,but I don't know why map doesn't zoom at all and it's like this :

我试图简单地在地图上显示用户的位置，但我需要在应用程序启动时，地图应该缩放到当前位置，但我不知道为什么地图根本不缩放，就像这样：

Here is the code :

这是代码：

class MapViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!
    var locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()

        mapView.delegate = self
        mapView.showsUserLocation = true
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestWhenInUseAuthorization()
        locationManager.delegate = self
        DispatchQueue.main.async {
            self.locationManager.startUpdatingLocation()
        }
    }

    func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        let location = locations.last as! CLLocation
        let center = CLLocationCoordinate2D(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude)
        var region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))
        region.center = mapView.userLocation.coordinate
        mapView.setRegion(region, animated: true)
    }

回答by Shobhakar Tiwari

I faced similar issue and wasted 4 days thinking whats going wrong. Finally resolved with creating these lines of code in viewDidLoadMethod :

我遇到了类似的问题，浪费了 4 天的时间思考出了什么问题。最后通过在viewDidLoadMethod 中创建这些代码行来解决：

    //Zoom to user location
    let noLocation = CLLocationCoordinate2D()
    let viewRegion = MKCoordinateRegionMakeWithDistance(noLocation, 200, 200)
    mapView.setRegion(viewRegion, animated: false)
    mapView.showsUserLocation = true

In ViewDidLoadMethod add these new changes code :

在ViewDidLoad方法中添加这些新的更改代码：

override func viewDidLoad() {

    super.viewDidLoad()

    let locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest

    // Check for Location Services
    if (CLLocationManager.locationServicesEnabled()) {
        locationManager.requestAlwaysAuthorization()
        locationManager.requestWhenInUseAuthorization()
    }

    //Zoom to user location
    if let userLocation = locationManager.location?.coordinate {
        let viewRegion = MKCoordinateRegionMakeWithDistance(userLocation, 200, 200)
        mapView.setRegion(viewRegion, animated: false)
    }

    self.locationManager = locationManager

    DispatchQueue.main.async {
        self.locationManager.startUpdatingLocation()
    }

}

Hope this helps to resolve your issue. Feel free to post comment if any further issue. Thanks

希望这有助于解决您的问题。如果有任何进一步的问题，请随时发表评论。谢谢

回答by KuboAndTwoStrings

Here's another approach for Swift 3, XCode 8.2. First, write out a helper function:

这是 Swift 3，XCode 8.2 的另一种方法。首先，写出一个辅助函数：

let homeLocation = CLLocation(latitude: 37.6213, longitude: -122.3790)
let regionRadius: CLLocationDistance = 200
func centerMapOnLocation(location: CLLocation)
{
    let coordinateRegion = MKCoordinateRegionMakeWithDistance(location.coordinate,
                                           regionRadius * 2.0, regionRadius * 2.0)
    mapView.setRegion(coordinateRegion, animated: true)
}

Then, call in in viewDidLoad()

然后，呼入 viewDidLoad()

mapView.showsUserLocation = true
centerMapOnLocation(location: homeLocation)

This will start the app with the location specified in the variable zoomed in.

这将在放大的变量中指定的位置启动应用程序。

回答by Mile Dev

In Swift 4.2 there has been changes with this code. Here is how it works now:

在 Swift 4.2 中，这段代码发生了变化。这是它现在的工作原理：

import UIKit
import MapKit
import CoreLocation

class MapVC: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {

    @IBOutlet weak var mapView: MKMapView!
    var locationManager = CLLocationManager()
    let authorizationStatus = CLLocationManager.authorizationStatus()
    let regionRadius: Double = 1000

    override func viewDidLoad() {
        super.viewDidLoad()
        mapView.delegate = self
        locationManager.delegate = self
        configureLocationServices()
    }

    func centerMapOnUserLocation() {
        guard let coordinate = locationManager.location?.coordinate else {return}
        let coordinateRegion = MKCoordinateRegion(center: coordinate, latitudinalMeters: regionRadius, longitudinalMeters: regionRadius)
        mapView.setRegion(coordinateRegion, animated: true)
    }

    func configureLocationServices() {
        if authorizationStatus == .notDetermined {
            locationManager.requestAlwaysAuthorization()
        } else {
            return
        }
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        centerMapOnUserLocation()
    }

}

回答by hiren

Code:

代码：

import UIKit
import MapKit

class ViewController: UIViewController, CLLocationManagerDelegate, MKMapViewDelegate {

@IBOutlet weak var mapview: MKMapView!

let locationmanager = CLLocationManager()

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

    mapview.mapType = MKMapType.standard

    let location = CLLocationCoordinate2DMake(22.4651, 70.0771)

    let span = MKCoordinateSpanMake(0.5, 0.5)
    let region =  MKCoordinateRegionMake(location, span)
    mapview.setRegion(region, animated: true)

    let annonation = MKPointAnnotation()
    annonation.coordinate = location
    annonation.title = "Chandi Bazar"
    annonation.subtitle = "Jamnagar"
    //
    mapview.addAnnotation(annonation)

    self.locationmanager.requestWhenInUseAuthorization()

    if CLLocationManager.locationServicesEnabled()
    {
        locationmanager.delegate = self
        locationmanager.desiredAccuracy = kCLLocationAccuracyNearestTenMeters
        locationmanager.startUpdatingLocation()
    }
}

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
    let locValue:CLLocationCoordinate2D = manager.location!.coordinate
    print("locations = \(locValue.latitude) \(locValue.longitude)")

    locationmanager.stopUpdatingLocation()
}

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

    let annotationidentifier = "Annotationidentifier"

    var annotationview:MKAnnotationView
    annotationview = MKAnnotationView(annotation: annotation, reuseIdentifier: annotationidentifier)

    let btn = UIButton(type: .detailDisclosure)

    btn.addTarget(self, action: #selector(ViewController.hirenagravat(sender:)), for: .touchUpInside)

    annotationview.rightCalloutAccessoryView = btn

    annotationview.image = UIImage(named: "images (4).jpeg")

    annotationview.canShowCallout = true

    return annotationview
}

func hirenagravat(sender:UIButton)
{
    let fvc = storyboard?.instantiateViewController(withIdentifier: "secondViewController") as? secondViewController
    self.navigationController?.pushViewController(fvc!, animated: true)
}

回答by Jovan Stankovic

Try with MKMapViewDelegate func:

尝试使用 MKMapViewDelegate 函数：

var isInitiallyZoomedToUserLocation: Bool = false 

func mapView(_ mapView: MKMapView, didUpdate userLocation: MKUserLocation) {
    if !isInitiallyZoomedToUserLocation {
       isInitiallyZoomedToUserLocation = true
       mapView.showAnnotations([userLocation], animated: true)
    }
}

回答by coders

when you set region -> you cannot zoom the map anymore. below to fix that

当您设置区域时 -> 您无法再缩放地图。下面来解决这个问题

func yourFuncName() {
//this is global var
regionHasBeenCentered = false
if !self.regionHasBeenCentered {
    let span: MKCoordinateSpan = MKCoordinateSpanMake(0.01, 0.01)
    let userLocation: CLLocationCoordinate2D = CLLocationCoordinate2DMake(_cllocationOfUserCurrentLocation!.coordinate.latitude, _cllocationOfUserCurrentLocation!.coordinate.longitude)
    let region: MKCoordinateRegion = MKCoordinateRegionMake(userLocation, span)

    self.mapView.setRegion(region, animated: true)
    self.regionHasBeenCentered = true
    }

    self.mapView.showsUserLocation = true
}

回答by Gurjinder Singh

In swift 4.1. To change the Zoom level you need to change the span value i.e MKCoordinateSpan(latitudeDelta: 0.95, longitudeDelta: 0.95)

在swift 4.1 中。要更改缩放级别，您需要更改跨度值，即MKCoordinateSpan(latitudeDelta: 0.95, longitudeDelta: 0.95)

 let lat =  "33.847105"
    let long = "-118.2673272"
    let region = MKCoordinateRegion(center: CLLocationCoordinate2D(latitude: Double(lat)!, longitude: Double(long)!), span: MKCoordinateSpan(latitudeDelta: 0.95, longitudeDelta: 0.95))
    DispatchQueue.main.async {
        self.mapView.setRegion(region, animated: true)
    }

Swift 5.0

斯威夫特 5.0

let span = MKCoordinateSpan.init(latitudeDelta: 0.01, longitudeDelta:
0.01)
let coordinate = CLLocationCoordinate2D.init(latitude: 21.282778, longitude: -157.829444) // provide you lat and long 
let region = MKCoordinateRegion.init(center: coordinate, span: span)
mapView.setRegion(region, animated: true)

回答by Anirudha Mahale

func animateToUserLocation() {
    if let annoation = mapView.annotations.filter ({ ##代码## is MKUserLocation }).first {
        let coordinate = annoation.coordinate
        let viewRegion = MKCoordinateRegion(center: coordinate, latitudinalMeters: 200, longitudinalMeters: 200)
        mapView.setRegion(viewRegion, animated: true)
    }
}