插入時未存儲在數組中的座標

Question

我試圖將座標存儲在數組中。代碼運行良好，但是在每次迭代新實現的座標之後，數組數仍然保持不變？

let manager = CLLocationManager() 

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    let location = locations[0] 
    let span:MKCoordinateSpan = MKCoordinateSpanMake(0.01,0.01) //shows the size of map screen 
    let myLocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude,location.coordinate.longitude) 
    let region:MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span) 
    map.setRegion(region, animated: true) 
    self.map.showsUserLocation = true 
    let LAT = Double(location.coordinate.latitude) 
    let LONG = Double(location.coordinate.longitude) 
    var locationArray = [Double]() 
    locationArray.insert(contentsOf: [LAT, LONG], at: 0) 
    print(locationArray.count) 

Answer 1

發生這種情況是因爲您正在每次迭代中創建一個新的locationArray。您需要聲明位於更新範圍之外的locationArray，在此處插入座標。

var locationArray = [Double]() 

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) { 
    let location = locations[0] 
    let span:MKCoordinateSpan = MKCoordinateSpanMake(0.01,0.01) //shows the size of map screen 
    let myLocation:CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude,location.coordinate.longitude) 
    let region:MKCoordinateRegion = MKCoordinateRegionMake(myLocation, span) 
    map.setRegion(region, animated: true) 
    self.map.showsUserLocation = true 
    let LAT = Double(location.coordinate.latitude) 
    let LONG = Double(location.coordinate.longitude) 
    locationArray.insert(contentsOf: [LAT, LONG], at: 0) 
    print(locationArray.count) 
}