如何在 Swift 中的位置点之间创建一条线（折线）？

Question

我正在尝试制作一个应用程序来跟踪用户的位置并在用户去过的地方创建一条线。我在用户去过的地方创建了一堆注释，但不知道如何在它们之间创建一条线。我是 swift 和 Xcode 的新手，我在整个互联网上都看过，但找不到任何有用的东西。 Picture of app with annotations following user location

这是我的代码：

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {
    @IBOutlet var mapView: MKMapView?

    //Map
    @IBOutlet weak var map: MKMapView!
    @IBOutlet weak var lblSpeed: UILabel!

    let manager = CLLocationManager()

    @IBOutlet weak var lblAltitude: UILabel!

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        let location = locations[0]

        let span:MKCoordinateSpan = MKCoordinateSpanMake(0.01, 0.01)

        let myLocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)

        let region:MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span)

        lblAltitude.text = String(format:"%.2f", location.altitude)
        lblSpeed.text = String(format:"%.2f", location.speed)

        self.map.showsUserLocation = true

        var testLocation = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)

        var annotation = MKPointAnnotation()
        annotation.coordinate = testLocation
        map.addAnnotation(annotation)

        var locationTest = [CLLocation(latitude: location.coordinate.latitude, longitude: location.coordinate.longitude)]
        var coordinates = locations.map({(location: CLLocation!) -> CLLocationCoordinate2D in return location.coordinate})
        var polyline = MKPolyline(coordinates: &testLocation, count: locations.count)

        func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
            if overlay is MKPolyline {
                let polylineRenderer = MKPolylineRenderer(overlay: overlay)
                polylineRenderer.strokeColor = UIColor.blue
                polylineRenderer.lineWidth = 5
                return polylineRenderer
            }

            return nil
        }
    }

Answer 1

你可以试试

let blueLocation1 = CLLocationCoordinate2D(latitude: lat1, longitude: lon1)       

let blueLocation2 = CLLocationCoordinate2D(latitude: lat2, longitude: lon2)

let routeLine = MKPolyline(coordinates:[blueLocation1,blueLocation2], count:2)

self.mapView.add(routeLine)

// 你也可能热衷于缩小以显示所有注释 + 看到画线

func zoomToFitMapAnnotations(aMapView:MKMapView)
{
    if(aMapView.annotations.count == 0)
    {
        return
    }


    var topLeftCoord = CLLocationCoordinate2D.init(latitude: -90, longitude: 180)


    var bottomRightCoord = CLLocationCoordinate2D.init(latitude: 90, longitude: -180)


    for i in 0..<aMapView.annotations.count
    {
        let annotation = aMapView.annotations[i]

        topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
        topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);

        bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
        bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
    }


    let resd = CLLocationCoordinate2D.init(latitude: topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5, longitude: topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5)

    let span = MKCoordinateSpan.init(latitudeDelta: fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.3, longitudeDelta: fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.3)

    var region = MKCoordinateRegion.init(center: resd, span: span);



    region = aMapView.regionThatFits(region)

    aMapView.setRegion(region, animated: true)


}

// 另外rendererForOverlay func 必须在类级别而不是在另一个 func 中

 func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer! {
        if overlay is MKPolyline {
            let polylineRenderer = MKPolylineRenderer(overlay: overlay)
            polylineRenderer.strokeColor = UIColor.blue
            polylineRenderer.lineWidth = 5
            return polylineRenderer
        }

        return nil
    }