CoreLocation用户速度

Question

我目前正在尝试获取当前用户的设备移动速度。这是我的代码：

import UIKit
import Foundation
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate {

let manager = CLLocationManager()
var currentSpeed = 0.0

override func viewDidLoad() {
    super.viewDidLoad()

    manager.requestWhenInUseAuthorization()

    manager.delegate = self
    manager.desiredAccuracy = kCLLocationAccuracyHundredMeters
    manager.startUpdatingLocation()
}

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
    print(manager.location?.speed)
}

func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
    print("Error: \(error.localizedDescription)")
}

唯一的问题是它会打印 "Optional(-1,0)"

我在这里先向您的帮助表示感谢。

Answer 1

如果设备不移动或移动速度太慢而数学运算没有意义，那么“核心位置”将为您提供一个负值的速度。

https://developer.apple.com/library/ios/documentation/CoreLocation/Reference/CLLocation_Class/#//apple_ref/occ/instp/CLLocation/speed