我想取出代表中获得的坐标

Question

我编写了一个程序，使用LocationManagerDelegate在当前位置发生变化时显示调试区域中的坐标。检索坐标时出错

不能在属性初始值设定项中使用实例成员'locationManager';属性初始化程序在'self'可用之前运行

import UIKit
import CoreLocation

class ViewController: UIViewController, CLLocationManagerDelegate{

var locationManager: CLLocationManager!

override func viewDidLoad() {
    super.viewDidLoad()
     // Do any additional setup after loading the view, typically from a nib.

   setUpLocationManager()
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

func setUpLocationManager() {
    locationManager = CLLocationManager()
    guard let locationManager = locationManager else {return}
    locationManager.requestWhenInUseAuthorization()
    let status = CLLocationManager.authorizationStatus()
    if status == .authorizedWhenInUse {
        locationManager.delegate = self
        locationManager.distanceFilter = 10
        locationManager.startUpdatingLocation()
        printLocation()
    }
}


func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) ->Optional<Any> {
    let location = locations.first
    let latitude = location?.coordinate.latitude
    let longitude = location?.coordinate.longitude
    let latlong = [latitude, longitude]
    return latlong
}
let myLocation = locationManager()

func printLocation() {
    print("test\(myLocation)")
}

}

输出test（Function）

let myLocation = locationManager ()

当你改为

let myLocation = locationManager

Answer 1

您的代码包含一些错误。

发生此错误是因为您无法在类的顶级执行受影响的行。

---

首先，您不得更改委托方法的签名。这个自定义委托方法

func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) ->Optional<Any> { ...

永远不会被召唤。

除此之外，为什么你将返回类型声明为Any?虽然它应该是[CLLocationCoordinate2D]？

---

• 立即创建位置管理器，替换 var locationManager: CLLocationManager! 同 let locationManager = CLLocationManager()
• 在setUpLocationManager()删除行

  locationManager = CLLocationManager()
  guard let locationManager = locationManager else {return} // this line is completely pointless anyway
  
  
  
  printLocation()

• 委托方法didUpdateLocations定期和异步调用。在方法内打印结果

  func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
      guard let location = locations.first else { return }
      let latitude = location.coordinate.latitude
      let longitude = location.coordinate.longitude
      let latlong = [latitude, longitude]
      print("test", latlong)
  }

• 删除

  let myLocation = locationManager()
  
  func printLocation() {
      print("test\(myLocation)")
  }