CLLocationDistance不工作-斯威夫特

Question

这段代码有问题，我无法计算出两个位置之间的距离。我已经在网上搜索过了，但是我解决不了。下面是我的didUpdateLocations函数：

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

    var userLocation:CLLocation = locations[0] as CLLocation
    var startLocation = userLocation
    var endLocation = userLocation
    if x == 0 {
        var startLocation = userLocation
        star.text = "\(startLocation)"
    }
    if x > 0 {
        var endLocation = userLocation
        end.text = "\(endLocation)"
        let distance: CLLocationDistance = startLocation.distanceFromLocation(endLocation)
        println(distance)
    }
    x = x + 1
}

Answer 1

您只需要将var startLocation声明为可选的，而不是在函数中声明。

var startLocation :CLLocation! 

然后，在您的didUpdate函数中，只需要测试startLocation变量是否为零：

func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
    if startLocation == nil {
        startLocation = locations.first as? CLLocation
    }
    let distance = startLocation.distanceFromLocation(locations.last as! CLLocation)
    println( "\(startLocation)")
    println( "\(locations.last as! CLLocation)")
    println("DISTANCE: \(distance)")
}

Answer 2

很多Tks！

我得做些改变

var startLocation :CLLocation!
var endLocation :CLLocation!

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

     var userLocation:CLLocation = locations[0] as CLLocation

    if startLocation == nil {
        startLocation = locations.first as? CLLocation
    }
    endLocation = locations.last as? CLLocation

    let distance = startLocation.distanceFromLocation(endLocation)

        println("DISTANCE: \(distance)")
        VDistancia.text = "\(distance)"
        VInical.text = "\(startLocation)"
        VSpeed.text = "\(userLocation.speed)"

}

这是工作！这些值不正确，但我将研究如何修复它。tks！