Question

我已经做了几个月的iOS开发，最近我正在开发一个总线应用程序。

我目前正在模仿公交车的动作，并在公交车站设置了多个注释。出于测试目的，我只设置了一个公共汽车站，并试图监控公共汽车何时进入该区域并退出。

奇怪的是，我的didStartMonitoringForRegion方法被称为完美，但didEnterRegion和didExitRegion方法都没有被调用。除此之外，不会出现任何错误。每次我运行程序时，公共汽车都会在不提示我的情况下通过停靠点。

有人可以向我解释为什么会这样，以及如何解决它？

//  ViewController.swift
//  Parta Service
//  Created by Emil Shirima on 8/24/15.
//  Copyright (c) 2015 Emil Shirima. All rights reserved.

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate,   CLLocationManagerDelegate {

@IBOutlet weak var mapView: MKMapView!

let locationManager = CLLocationManager()
var allBusAnnotations = [MKPointAnnotation]()
var summitEastBusStations = [CLLocationCoordinate2D]()
var busStopNames = ["Dix Stadium", "Risman Plaza", "Terrace Drive", "Terrace Drive 2","C-Midway","Theatre Dr.","East Main Street","South Lincoln"]
var radius = 250 as CLLocationDistance

// 0.02 is the best zoom in factor
var mapZoomInFactor : Double = 0.02

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

    self.getBusStop()
    self.locationManager.delegate = self
    // gets the exact location of the user
    self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
    // gets the user's location only when the app is in use and not background
    self.locationManager.requestWhenInUseAuthorization()
    self.locationManager.startUpdatingLocation()

    self.mapView.showsUserLocation = true
    self.setBusStopAnnotations(summitEastBusStations)

    self.canDeviceSupportAppBackgroundRefresh()

}

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

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

    // sends the latitude and longitude to the Apple Servers then returns the address
    CLGeocoder().reverseGeocodeLocation(manager.location, completionHandler: { (placeMarks: [AnyObject]!, error: NSError!) -> Void in

        if error != nil
        {
            println("Reverse Geocode Failed: " + error.localizedDescription)
            println("The real reason is " + error.localizedFailureReason!)
            return
        }

        if placeMarks.count > 0
        {
            // gets the most updated location
            let pm = placeMarks.last as! CLPlacemark

            let centre = CLLocationCoordinate2D(latitude: manager.location.coordinate.latitude, longitude: manager.location.coordinate.longitude)

            // draws a circle in which the map will zoom to
            let region = MKCoordinateRegion(center: centre, span: MKCoordinateSpan(latitudeDelta: self.mapZoomInFactor, longitudeDelta: self.mapZoomInFactor))

            self.mapView.setRegion(region, animated: true)

            self.displayLocationInfo(pm)

            self.geoFencing()
        }
    })
}

func displayLocationInfo(placemark: CLPlacemark)
{

    println("Current Location:")
    println(placemark.name)
}

func locationManager(manager: CLLocationManager!, didFailWithError error: NSError!) {
    println("Location Manager Failed: " + error.localizedDescription)
}

func locationManager(manager: CLLocationManager!, didStartMonitoringForRegion region: CLRegion!) {
    println("The monitored regions are: \(locationManager.monitoredRegions)")
}

func locationManager(manager: CLLocationManager!, monitoringDidFailForRegion region: CLRegion!, withError error: NSError!) {
    println("Failed to monitor the stated region")
}

func locationManager(manager: CLLocationManager!, didEnterRegion region: CLRegion!) {
    println("The bus has entered the region")

    createAlert("Region Entry", alertMessage: "You have entered the specified region", alertCancelTitle: "OK")
}

func locationManager(manager: CLLocationManager!, didExitRegion region: CLRegion!) {
    println("The bus has left the region")

    createAlert("Region Exit", alertMessage: "You have exited the specified region", alertCancelTitle: "OK")
}

//TODO:Implement GeoFencing in order to know when the bus is at a station or not.
func geoFencing()
{
    locationManager.requestAlwaysAuthorization()
    let rismanPlaza = CLLocationCoordinate2D(latitude: 41.1469492, longitude: -81.344068)

    var currentBusStop = CLLocation(latitude: rismanPlaza.latitude, longitude: rismanPlaza.longitude)
    addRadiusCircle(currentBusStop)

    let busStopRegion = CLCircularRegion(center: CLLocationCoordinate2D(latitude: rismanPlaza.latitude, longitude: rismanPlaza.longitude), radius: radius, identifier: busStopNames[1])

    if radius > self.locationManager.maximumRegionMonitoringDistance
    {
        radius = self.locationManager.maximumRegionMonitoringDistance
    }

    if CLLocationManager.isMonitoringAvailableForClass(CLCircularRegion)
    {
        locationManager.startMonitoringForRegion(busStopRegion)
    }
    else
    {
        //TODO: Create an alert telling the user that region tracking for this area is not available
        println("Monitoring is not available for this region")
    }

}

// creates the radius around the specified location
func addRadiusCircle(location: CLLocation)
{
    self.mapView.delegate = self
    var circle = MKCircle(centerCoordinate: location.coordinate, radius: radius)
    self.mapView.addOverlay(circle)
}

// performs the actual circle colouring
func mapView(mapView: MKMapView!, rendererForOverlay overlay: MKOverlay!) -> MKOverlayRenderer!
{
    if overlay is MKCircle
    {
        var circle = MKCircleRenderer(overlay: overlay)
        circle.strokeColor = UIColor.redColor()
        circle.fillColor = UIColor(red: 255, green: 0, blue: 0, alpha: 0.1)
        circle.lineWidth = 1
        return circle
    }
    else
    {
        return nil
    }
}

// removes the drawn circles from the map
func removeCircleLayers()
{
    var layers = mapView.overlays
    mapView.removeOverlays(layers)
}

func canDeviceSupportAppBackgroundRefresh()
{
    if UIApplication.sharedApplication().backgroundRefreshStatus == UIBackgroundRefreshStatus.Available
    {
        createAlert("Background Refresh Status", alertMessage: "Background Updates are enable for the App", alertCancelTitle: "OK")
    }
    else if UIApplication.sharedApplication().backgroundRefreshStatus == UIBackgroundRefreshStatus.Denied
    {
        createAlert("Background Refresh Status", alertMessage: "Background Updates are disabled by the user for the App", alertCancelTitle: "OK")
    }
    else if UIApplication.sharedApplication().backgroundRefreshStatus == UIBackgroundRefreshStatus.Restricted
    {
        createAlert("Background Refresh Status", alertMessage: "Background Updates are restricted and the user can't do anything App", alertCancelTitle: "OK")
    }

}

func createAlert(alertTitle: String, alertMessage: String, alertCancelTitle: String)
{
    let alert = UIAlertView(title: alertTitle, message: alertMessage, delegate: self, cancelButtonTitle: alertCancelTitle)
    alert.show()
}

}

Answer 1

我最终使用了CLRegion.containsCoordinate(location.coordinate)方法。它的工作原理大致相同。

一旦对象进入我的设置区域，它就会返回true，从这里我可以知道它何时进入并退出该区域。

Answer 2

如果用户设备位于当前位置（纬度和经度） didEnterRegion ：和 didExitRegion ：代理将不会触发。使用 didDetermineState ：方法查找用户/设备是否处于被监控的当前区域。如果是这样，didDetermineState：将被触发。一旦用户离开该区域，将触发didExitRegion：

不调用位置管理器didEnterRegion和didExitRegion方法

2 个答案: