CLLocationDistance 不起作用 - swift

Question

我在使用这段代码时遇到问题，我无法计算两个位置之间的距离。我已经在互联网上搜索过，但无法解决。这是我的 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

您只需将 var startLocation 声明为可选但不在您的函数内。

var startLocation :CLLocation!

然后在 didUpdate 函数中测试 startLocation 变量是否为 nil:

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

非常感谢！

我必须做这个改变

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)"

}

成功了！这些值不正确，但我会搜索如何修复它。谢谢！

CLLocationDistance 不起作用 - swift

CLLocationDistance not working - swift

xcode

mapkit

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ios

swift