Question

嗨，我似乎只能将nil作为我的位置变量，而我正在编写一个简单的位置接收类。我已经搜索了堆栈溢出一段时间并尝试了很多解决方案，但我似乎无法修复它。

以下是我的代码。我尝试使用方法，一种是在didUpdateLocations方法中的结构中设置变量。另一种是更新变量userLocation。两者现在只是给我的零，我无法弄清楚原因。

class SendLocation:  NSObject, CLLocationManagerDelegate{


var userLocation: CLLocation? = nil
var locationManager:CLLocationManager!


struct LocationStruct{
    var latitude:CLLocationDegrees?, longitude:CLLocationDegrees?
}

var locationStruct = LocationStruct()


func sendLocationPost(){
    determineCurrentLocation()
    print(userLocation) // This is nil
    print(locationStruct.latitude) // This is nil
    print(locationStruct.longitude) // This is nil

}

func determineCurrentLocation(){
    locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestAlwaysAuthorization()
    if CLLocationManager.locationServicesEnabled(){
        locationManager.startUpdatingLocation()
    }
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]){
    userLocation = locations[0] as CLLocation
    print(userLocation) // This IS NOT nil
    locationStruct.latitude=userLocation?.coordinate.latitude
    locationStruct.longitude=userLocation?.coordinate.longitude

}

提前感谢您的帮助，因为我知道这将是简单/愚蠢的事情

Answer 1

这只是理解事情需要时间的问题。你正在向前迈进，好像开始获得一个位置可以立即为你提供一个位置。但它没有：

-fdebug-prefix-map=$PWD=.

当您第一次拨打func sendLocationPost(){ determineCurrentLocation() // so now things start... but they take _time_...! print(userLocation) // This is nil // because it's _too soon!_ // ... }时，传感器预热需要很长时间才能到达良好的位置：

determineCurrentLocation

最后，经过一些重要的时间，也许，也许，也许，我们终于开始得到一些更新，经过一段时间，也许他们不是零：

func determineCurrentLocation(){
    locationManager = CLLocationManager()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestAlwaysAuthorization()
    if CLLocationManager.locationServicesEnabled(){
        locationManager.startUpdatingLocation()
        // SLOWLY... things now start to happen
    }
}

现在我们有一个位置。但与此同时，func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]){ userLocation = locations[0] as CLLocation print(userLocation) // This IS NOT nil locationStruct.latitude=userLocation?.coordinate.latitude locationStruct.longitude=userLocation?.coordinate.longitude }中的代码很久以前就已结束，并获得了sendLocationPost。

Swift - 在函数之间设置值时获取nil的麻烦

1 个答案: