Swift CLLocationManager(didUpdateLocations) 被调用太频繁答案

【问题标题】：Swift CLLocationManager(didUpdateLocations) is called too oftenSwift CLLocationManager(didUpdateLocations) 被调用太频繁
【发布时间】：2016-05-29 21:00:55
【问题描述】：

谁能解释一下，为什么委托方法“CLLocationManager(didUpdateLocations)”被调用了 4 次，尽管我立即停止更新？我只需要一次当前位置:)

import UIKit
import MapKit

class ContactView: UIViewController, CLLocationManagerDelegate {

    let clLocationManager = CLLocationManager()

    var latitude: AnyObject = 0.000000
    var longitude: AnyObject = 0.000000

    override func viewDidLoad() {
        super.viewDidLoad()
        self.nameTextField.delegate = self
        clLocationManager.delegate = self
        clLocationManager.desiredAccuracy = kCLLocationAccuracyBest
        clLocationManager.requestWhenInUseAuthorization()
        clLocationManager.startUpdatingLocation()
    }

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

    func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {
            (placemarks, error) -> Void in
            self.clLocationManager.stopUpdatingLocation()
            if placemarks!.count > 0 {
                self.latitude = (manager.location?.coordinate.latitude)!
                self.longitude = (manager.location?.coordinate.longitude)!
                print(self.latitude)
                print(self.longitude)
            } else {
                print("Error")
            }
        })
    }
}

谢谢！

【问题讨论】：

标签： swift delegates mapkit core-location cllocationmanager

【解决方案1】：

你需要像下面这样改变你的代码：

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    manager.stopUpdatingLocation()
    CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {
        (placemarks, error) -> Void in
        if placemarks!.count > 0 {
            self.latitude = (manager.location?.coordinate.latitude)!
            self.longitude = (manager.location?.coordinate.longitude)!
            print(self.latitude)
            print(self.longitude)
        } else {
            print("Error")
        }
    })
}

您看到问题是因为您在继续更新您的位置，而对您的位置进行反向地理编码的调用仍在进行中。

【讨论】：

【解决方案2】：

尝试将 stopUpdatingLocation 移出 reverseGeocodeLocation

 func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    manager.stopUpdatingLocation()
    CLGeocoder().reverseGeocodeLocation(manager.location!, completionHandler: {
                (placemarks, error) -> Void in
                if placemarks!.count > 0 {
                    self.latitude = (manager.location?.coordinate.latitude)!
                    self.longitude = (manager.location?.coordinate.longitude)!
                    print(self.latitude)
                    print(self.longitude)
                } else {
                    print("Error")
                }
            })
        }
    }

【讨论】：