Question

所以我有一个主视图，它只包含一个tableview，然后是一个名为RouteViewController的第二个视图控制器，它由mapView和UITextView组成。我得到用户的当前位置，如果位置管理器失败，那么我会向他们显示有关它的警报。容易吗？

但是每次调用警报视图控制器时，我都会首先收到以下警告：

警告：尝试显示UIAlertController：0x7cb58200 “AppName”.RouteViewController：0x7e4450e0，同时演示文稿在进步！

警报确实出现了，我可以取消它和一切。然后当我回到我的桌面视图并点击另一个项目时，我这次收到以下警告：

尝试加载视图控制器的视图不允许取消分配，可能导致未定义的行为（UIAlertController：0x7cb58200）

就像之前一样，警报出现，我甚至可以取消它。

我已经找到了解决方案，但到目前为止还没有任何实用方法。

PS：我保留locations.count > 100以便在位置管理员失败时尝试模拟方案

提前感谢您的任何帮助。

//  RouteViewController.swift
import UIKit
import MapKit
import CoreLocation

class RouteViewController: UIViewController, MKMapViewDelegate,   CLLocationManagerDelegate {

@IBOutlet weak var routeDescriptionTextView: UITextView!
@IBOutlet weak var mapView: MKMapView!

var route: Routes?
let locationManager = CLLocationManager()

func updateRouteView()
{
    let routeName = "\((route?.routeName)!)"
    let routeNumber = "\((route?.routeNumber)!)"
    let routeDescription = ((route?.routeDescription)! as NSArray).componentsJoinedByString("\n")
    let routeTimes = "\((route?.routeTimes)!)"
    let routeDaysOfOperation = ((route?.routeDaysOfOperation)! as NSArray).componentsJoinedByString(", ")
    routeDescriptionTextView.text = "Route Name: \(routeName) \n\n Route Number: \(routeNumber) \n\n \(routeDescription) \n\n \(routeDaysOfOperation) \n\n \(routeTimes)"
}

func showAlertToUser(errorTitle: String, errorMessage: String)
{
    let alert = UIAlertController(title: errorTitle, message: errorMessage, preferredStyle: .Alert)

    alert.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))

    self.presentViewController(alert, animated: true, completion: nil)
}

override func viewDidLoad() {
    super.viewDidLoad()

    updateRouteView()
    title = "\((route?.routeName)!)"

    routeDescriptionTextView.contentInset = UIEdgeInsetsMake(1.0, 0.0, 0.0, 0.0) // this is for the textview scrolling size

    self.locationManager.delegate = self
    self.locationManager.desiredAccuracy =  kCLLocationAccuracyBest
    self.locationManager.requestWhenInUseAuthorization() // change to always if background needed
    self.locationManager.startUpdatingLocation()
    self.mapView.showsUserLocation = true
}

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

//TODO: Make this better. I don't like the way it is at the moment.
//TODO: Make location tracker work when app is in the background

func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation])
{
    if (locations.count > 100)
    {
        let location = locations.last
        let center = CLLocationCoordinate2D(latitude: (location?.coordinate.latitude)!, longitude: (location?.coordinate.longitude)!)
        let region = MKCoordinateRegion(center: center, span: MKCoordinateSpan(latitudeDelta: 1, longitudeDelta: 1))
        self.mapView.setRegion(region, animated: true)
        self.locationManager.stopUpdatingLocation()
    }
}

//TODO: Add an alert to the user for the locationManagerError
//TODO: Okay, the above TODO is partially complete.Fix the warnings received from view presentation

func locationManager(manager: CLLocationManager, didFailWithError error: NSError)
{
    showAlertToUser("Location Manager Error", errorMessage: error.localizedDescription)
}

/*
// MARK: - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    // Get the new view controller using segue.destinationViewController.
    // Pass the selected object to the new view controller.
}
*/

}

在取消分配时尝试加载视图控制器的视图... <uialertcontroller>

0 个答案: