Swift: "mapView.showUserLocation = true" возвращает "фатальную ошибку: неожиданно найдено нуль при развертывании необязательного значения (lldb)"

Question

Итак, я пытаюсь искать местные компании в Swift с использованием таких ключевых слов, как «bar», пицца". Я связал поиск с действием кнопки, чтобы местоположения появлялись на карте в пределах определенной области. Тем не менее, я даже не могу заставить приложение загружаться с местоположением пользователя, потому что получаю нулевую ошибку.

Вот мой AppDelegate:

import UIKit 
import CoreLocation 

@UIApplicationMain 
class AppDelegate: UIResponder, UIApplicationDelegate { 

var window: UIWindow? 
var locationManager: CLLocationManager? 

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool { 
    // Override point for customization after application launch. 
    locationManager = CLLocationManager() 
    locationManager?.requestWhenInUseAuthorization() 
    return true 
} 

func applicationWillResignActive(application: UIApplication) { 
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state. 
    // Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game. 
} 

func applicationDidEnterBackground(application: UIApplication) { 
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later. 
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits. 
} 

func applicationWillEnterForeground(application: UIApplication) { 
    // Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background. 
} 

func applicationDidBecomeActive(application: UIApplication) { 
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface. 
} 

func applicationWillTerminate(application: UIApplication) { 
    // Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:. 
} 


} 

А вот мой ViewController.swift:

import Foundation 
import UIKit 
import MapKit 

class ViewController: UIViewController, MKMapViewDelegate { 

@IBOutlet weak var mapView: MKMapView! 

@IBAction func searchBars(sender: AnyObject) { 
    let request = MKLocalSearchRequest() 
    request.naturalLanguageQuery = "Bar" 
    request.region = mapView.region 

    let search = MKLocalSearch(request: request) 
    search.startWithCompletionHandler({(response: MKLocalSearchResponse!, error: NSError!) in 

     if error != nil { 
      println("Error occurred in search: \(error.localizedDescription)") 
     } else if response.mapItems.count == 0 { 
      println("No matches found") 

      for item in response.mapItems as [MKMapItem] { 
       println("Name = \(item.name)") 
       println("Phone = \(item.phoneNumber)") 
      } 
     } 
     }) 

} 

func mapView(mapView: MKMapView!, didUpdateUserLocation userLocation: MKUserLocation!) { 
    mapView.centerCoordinate = userLocation.location.coordinate 
} 

override func viewDidLoad() { 
    super.viewDidLoad() 
    // Do any additional setup after loading the view, typically from a nib. 
    mapView.showsUserLocation = true 
    mapView.delegate = self 
} 

@IBAction func zoomIn(sender: AnyObject) { 
    let userLocation = mapView.userLocation 

    let region = MKCoordinateRegionMakeWithDistance(userLocation.location.coordinate, 2000, 2000) 
} 

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


} 

Строка, которая возвращает ноль ошибка в моем файле ViewController.swift под @IBAction Func ZoomIn с line: let region = MKCoordinateRegionMakeWithDistance (userLocation.location.coordinate, 2000, 2000). По какой-то причине это дает нулевое значение.

Answer 1

Что вы делаете с этой строкой, это создание объекта mapView, который еще не создан.

weak var mapView: MKMapView! 

Вы получаете ошибку, потому что вы пытаетесь изменить showsUserLocation свойство объекта, который еще не существует, это ноль.

Что вам нужно сделать, если вы создали карту в раскадровке, это удалить слабую строку var и поместить вместо нее IBOutlet (Ctrl + Click и перетащить из раскадровки).

Answer 2

Большое спасибо Skoua за помощь. Я выяснил, что было не так, когда помог мне с IBOutlet.

Вот исправленный код.

@IBAction func searchBars(sender: AnyObject) { 
    matchingItems.removeAll() 
    let request = MKLocalSearchRequest() 
    request.naturalLanguageQuery = "bar" 
    request.region = mapView.region 

    let search = MKLocalSearch(request: request) 
    search.startWithCompletionHandler({(response: MKLocalSearchResponse!, error: NSError!) in 

     if error != nil { 
      println("Error occurred in search: \(error.localizedDescription)") 
     } else if response.mapItems.count == 0 { 
      println("No matches found") 
//This is where the problem occured 
     } else { 
      println("Matches found") 
     //I needed to insert an else statement for matches being found 
      for item in response.mapItems as [MKMapItem] { 
       //This prints the 'matches' into [MKMapItem] 
       println("Name = \(item.name)") 
       println("Phone = \(item.phoneNumber)") 

       self.matchingItems.append(item as MKMapItem) 
       println("Matching items = \(self.matchingItems.count)") 

       var annotation = MKPointAnnotation() 
       annotation.coordinate = item.placemark.coordinate 
       annotation.title = item.name 
       self.mapView.addAnnotation(annotation) 
      } 
     } 
     }) 

}