我想在 swift 代码中访问第二个视图控制器中的 var

Question

你好，这是我到目前为止的代码

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {

    @IBOutlet var map: MKMapView!
    var locationManager = CLLocationManager()

    override func viewDidLoad() {
        super.viewDidLoad()
        locationManager.delegate = self
        locationManager.desiredAccuracy = kCLLocationAccuracyBest
        locationManager.requestWhenInUseAuthorization()
        locationManager.startUpdatingLocation()
    }

    func locationManager(manager: CLLocationManager!, didUpdateLocations locations: [AnyObject]!) {
        var userLocation:CLLocation = locations[0] as! CLLocation
        var latitude = userLocation.coordinate.latitude
        var longitude = userLocation.coordinate.longitude
        var latDelta:CLLocationDegrees = 0.05
        var lonDelta:CLLocationDegrees = 0.05
        var span:MKCoordinateSpan = MKCoordinateSpanMake(latDelta, lonDelta)
        var location:CLLocationCoordinate2D = CLLocationCoordinate2DMake(latitude, longitude)   
        var region:MKCoordinateRegion = MKCoordinateRegionMake(location, span)

        self.map.setRegion(region, animated: false)
        println(latitude)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

我想在显示 latitude、longitude、course 和 speed 的第二个视图控制器中访问 locationManager 函数中的信息.我是新手，所以任何帮助都会很棒。干杯

Answer 1

将要传递给第二个 VC 的变量从本地移动到 class-scope:

import UIKit
import MapKit
import CoreLocation

class ViewController: UIViewController, MKMapViewDelegate, CLLocationManagerDelegate {

    @IBOutlet var map: MKMapView!


   var locationManager = CLLocationManager()
   var longitude:CLLocationDegrees!
   var latitude:CLLocationDegrees!

  override func viewDidLoad() {
    super.viewDidLoad()
    locationManager.delegate = self
    locationManager.desiredAccuracy = kCLLocationAccuracyBest
    locationManager.requestWhenInUseAuthorization()
    locationManager.startUpdatingLocation()
}

使用变量创建目标 UIViewController 以保存传递的值：

import UIKit
import MapKit
import CoreLocation

class MyDestinationViewController: UIViewController {
  var longitude:CLLocationDegrees!
  var latitude:CLLocationDegrees!

    override func viewDidLoad() {
        super.viewDidLoad()
    }
}

将 prepareForSegue 方法添加到您要从中发送数据的 viewcontroller：

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    let destinationVC = segue.destinationViewController as! MyDestinationViewController
    destinationVC.latitude = latitude
    destinationVC.longitude = longitude
}

如果您不想使用 segue，您可以在呈现 VC.

之前实例化 targetViewController 并传递变量

我想在 swift 代码中访问第二个视图控制器中的 var

I want to access a var in a second view controller in swift code

uiviewcontroller

ios

swift