Apple Maps搜索尝试给出了SIGABRT

Question

我在项目中使用本教程并在最后一步遇到错误。每次我在搜索字段中输入内容时，应用程序都会崩溃并显示错误SIGABRT。我知道教程中的初始代码已经过时，我已经更新了它，只要Xcode提示我。 Xcode还告诉我不要覆盖cellForRow和didSelectCell，这看似奇怪，但我不确定。这是MapViewController：

import UIKit
import MapKit
import CoreLocation

protocol HandleMapSearch {
    func dropPinZoomIn(placemark: MKPlacemark)
}

class MapViewController: UIViewController {
    @IBOutlet weak var myMapView: MKMapView!


    var locationManager = CLLocationManager()
    var resultSearchController:UISearchController? = nil
    var selectedPin:MKPlacemark? = nil

    override func viewDidLoad() {
        super.viewDidLoad()
      self.locationManager.requestWhenInUseAuthorization()

        if CLLocationManager.locationServicesEnabled() {
            locationManager.delegate = self
            locationManager.desiredAccuracy = kCLLocationAccuracyBest
            locationManager.startUpdatingLocation()

        }
        let locationSearchTable = storyboard!.instantiateViewController(withIdentifier: "LocationSearchTable") as! LocationSearchTable
        resultSearchController = UISearchController(searchResultsController: locationSearchTable)
        resultSearchController?.searchResultsUpdater = locationSearchTable
        let searchBar = resultSearchController!.searchBar
        searchBar.sizeToFit()
        searchBar.placeholder = "Search for places"
        navigationItem.titleView = resultSearchController?.searchBar
        resultSearchController?.hidesNavigationBarDuringPresentation = false
        resultSearchController?.dimsBackgroundDuringPresentation = true
        definesPresentationContext = true
        locationSearchTable.mapView = myMapView
        locationSearchTable.handleMapSearchDelegate = self
    }


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


    /*
    // MARK: - Navigation

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

    }
extension MapViewController : CLLocationManagerDelegate {

    func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
        print("error:: \(error.localizedDescription)")
    }

    func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
        myMapView.mapType = MKMapType.standard
        let location = locations[0]
        let myLocation: CLLocationCoordinate2D = CLLocationCoordinate2DMake(location.coordinate.latitude, location.coordinate.longitude)
        let span = MKCoordinateSpanMake(0.05, 0.05)
        let region = MKCoordinateRegion(center: myLocation, span: span)
        myMapView.setRegion(region, animated: true)
        self.myMapView.showsUserLocation = true
    }

    func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
        if status == .authorizedWhenInUse {
            locationManager.requestLocation()
        }
    }

}

extension MapViewController: HandleMapSearch {
    func dropPinZoomIn(placemark:MKPlacemark) {
        // cache the pin
        selectedPin = placemark
        // clear existing pins
        myMapView.removeAnnotations(myMapView.annotations)
        let annotation = MKPointAnnotation()
        annotation.coordinate = placemark.coordinate
        annotation.title = placemark.name
        if let city = placemark.locality,
            let state = placemark.administrativeArea {
            annotation.subtitle = "(city) (state)"
        }
        myMapView.addAnnotation(annotation)
        let span = MKCoordinateSpanMake(0.05, 0.05)
        let region = MKCoordinateRegionMake(placemark.coordinate, span)
        myMapView.setRegion(region, animated: true)
    }
}

这是LocationSearchTable：

import UIKit
import MapKit
class LocationSearchTable : UITableViewController {
    var matchingItems:[MKMapItem] = []
    var mapView: MKMapView? = nil
    var handleMapSearchDelegate:HandleMapSearch? = nil
    func parseAddress(selectedItem: MKPlacemark) -> String {
        // put a space between "4" and "Melrose Place"
        let firstSpace = (selectedItem.subThoroughfare != nil && selectedItem.thoroughfare != nil) ? " " : ""
        // put a comma between street and city/state
        let comma = (selectedItem.subThoroughfare != nil || selectedItem.thoroughfare != nil) && (selectedItem.subAdministrativeArea != nil || selectedItem.administrativeArea != nil) ? ", " : ""
        // put a space between "Washington" and "DC"
        let secondSpace = (selectedItem.subAdministrativeArea != nil && selectedItem.administrativeArea != nil) ? " " : ""
        let addressLine = String(
            format:"%@%@%@%@%@%@%@",
            // street number
            selectedItem.subThoroughfare ?? "",
            firstSpace,
            // street name
            selectedItem.thoroughfare ?? "",
            comma,
            // city
            selectedItem.locality ?? "",
            secondSpace,
            // state
            selectedItem.administrativeArea ?? ""
        )
        return addressLine
    }
}

extension LocationSearchTable : UISearchResultsUpdating {
    func updateSearchResults(for searchController: UISearchController) {
        guard let mapView = mapView,
            let searchBarText = searchController.searchBar.text else { return }
        let request = MKLocalSearchRequest()
        request.naturalLanguageQuery = searchBarText
        request.region = mapView.region
        let search = MKLocalSearch(request: request)
        search.start { response, _ in
            guard let response = response else {
                return
            }
            self.matchingItems = response.mapItems
            self.tableView.reloadData()
        }
    }
}

extension LocationSearchTable {
    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return matchingItems.count
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "cell")!
        let selectedItem = matchingItems[indexPath.row].placemark
        cell.textLabel?.text = selectedItem.name
        cell.detailTextLabel?.text = parseAddress(selectedItem: selectedItem)
        return cell
    }
}

extension LocationSearchTable {
    func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
        let selectedItem = matchingItems[indexPath.row].placemark
        handleMapSearchDelegate?.dropPinZoomIn(placemark: selectedItem)
        dismiss(animated: true, completion: nil)
    }
}

当我尝试在搜索字段中键入搜索时出现错误;所有这一切都会导致应用程序崩溃，错误为SIGABRT。它甚至不会将错误打印到日志中，所以我不知道发生了什么。非常感谢任何帮助。