Book (Swift for Dummies) Chapter 4 Exercise: fatal error: unexpectedly found nil while unwrapping an Optional value
Book (Swift for Dummies) Chapter 4 Exercise: fatal error: unexpectedly found nil while unwrapping an Optional value
我正在学习 swift，我正在阅读名为 "Swift for Dummies" 的书，我尝试按照作者的方法做书中的示例，但我在示例中遇到了问题第四章，大家能帮帮我吗
中的第 51 行出错
MasterViewController.swift
newManagedObject.latitude = self.lastLocation.coordinate.latitude
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) in
the output windows is shown fatal error: unexpectedly found nil while
unwrapping an Optional value (lldb)
import UIKit
import CoreData
import CoreLocation
class MasterViewController: UITableViewController,
NSFetchedResultsControllerDelegate,
CLLocationManagerDelegate
{
var detailViewController: DetailViewController? = nil
var managedObjectContext: NSManagedObjectContext? = nil
let locationManager = CLLocationManager()
var lastLocation: CLLocation! = nil
override func awakeFromNib() {
super.awakeFromNib()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem()
let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "insertNewObject:")
self.navigationItem.rightBarButtonItem = addButton
self.startSignificantChangeUpdates()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func insertNewObject(sender: AnyObject) {
let context = self.fetchedResultsController.managedObjectContext
let entity = self.fetchedResultsController.fetchRequest.entity!
let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName("Event", inManagedObjectContext: context) as! Event
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
newManagedObject.latitude = self.lastLocation.coordinate.latitude
newManagedObject.longitude = self.lastLocation.coordinate.longitude
// Save the context.
var error: NSError? = nil
if !context.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
// MARK: - Segues
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showDetail" {
if let indexPath = self.tableView.indexPathForSelectedRow() {
let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject
(segue.destinationViewController as! DetailViewController).detailItem = object
}
}
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return self.fetchedResultsController.sections?.count ?? 0
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let sectionInfo = self.fetchedResultsController.sections![section] as! NSFetchedResultsSectionInfo
return sectionInfo.numberOfObjects
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
self.configureCell(cell, atIndexPath: indexPath)
return cell
}
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
let context = self.fetchedResultsController.managedObjectContext
context.deleteObject(self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject)
var error: NSError? = nil
if !context.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
}
func configureCell(cell: UITableViewCell, atIndexPath indexPath: NSIndexPath) {
let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! Event
cell.textLabel!.text = "latitude: " + object.latitude.description + " longitude: " + object.longitude.description
}
// MARK: - Fetched results controller
var fetchedResultsController: NSFetchedResultsController {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest()
// Edit the entity name as appropriate.
let entity = NSEntityDescription.entityForName("Event", inManagedObjectContext: self.managedObjectContext!)
fetchRequest.entity = entity
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "timeStamp", ascending: false)
let sortDescriptors = [sortDescriptor]
fetchRequest.sortDescriptors = [sortDescriptor]
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
let aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.managedObjectContext!, sectionNameKeyPath: nil, cacheName: "Master")
aFetchedResultsController.delegate = self
_fetchedResultsController = aFetchedResultsController
var error: NSError? = nil
if !_fetchedResultsController!.performFetch(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
return _fetchedResultsController!
}
var _fetchedResultsController: NSFetchedResultsController? = nil
func controllerWillChangeContent(controller: NSFetchedResultsController) {
self.tableView.beginUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
switch type {
case .Insert:
self.tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
case .Delete:
self.tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
default:
return
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case .Insert:
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
case .Delete:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
case .Update:
self.configureCell(tableView.cellForRowAtIndexPath(indexPath!)!, atIndexPath: indexPath!)
case .Move:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
default:
return
}
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
self.tableView.endUpdates()
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
func controllerDidChangeContent(controller: NSFetchedResultsController) {
// In the simplest, most efficient, case, reload the table view.
self.tableView.reloadData()
}
*/
// MARK: CLLocationManagerDelegate Protocol
func startSignificantChangeUpdates () {
if CLLocationManager.authorizationStatus() == CLAuthorizationStatus.NotDetermined {
self.locationManager.requestWhenInUseAuthorization()
}
if CLLocationManager.locationServicesEnabled() {
self.locationManager.delegate = self
self.locationManager.distanceFilter = kCLDistanceFilterNone
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.startUpdatingLocation()
self.locationManager.startMonitoringSignificantLocationChanges()
}
}
func locationManager (manager: CLLocationManager!, didUpdateLocations locations:[AnyObject]!) {
self.lastLocation = manager.location
let eventDate = self.lastLocation.timestamp;
let howRecent = eventDate.timeIntervalSinceNow;
}
func locationManager(manager: CLLocationManager!, didFailWithError error: NSError!) {
// need to add code to catch errors
}
}
import UIKit
import MapKit
class DetailViewController: UIViewController {
@IBOutlet var mapView: MKMapView!
@IBOutlet weak var detailDescriptionLabel: UILabel!
var detailItem: AnyObject? {
didSet {
// Update the view.
self.configureView()
}
}
func configureView() {
// Update the user interface for the detail item.
if let detail: AnyObject = self.detailItem {
if let label = self.detailDescriptionLabel {
label.text = detail.valueForKey("timeStamp")!.description
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.configureView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
import Foundation
import CoreData
class Event: NSManagedObject {
@NSManaged var latitude: NSNumber
@NSManaged var longitude: NSNumber
@NSManaged var timeStamp: NSDate
}
import UIKit
import CoreData
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let navigationController = self.window!.rootViewController as! UINavigationController
let controller = navigationController.topViewController as! MasterViewController
controller.managedObjectContext = self.managedObjectContext
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:.
// Saves changes in the application's managed object context before the application terminates.
self.saveContext()
}
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.sauer.Locatapp" in the application's documents Application Support directory.
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as! NSURL
}()
lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("Locatapp", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
// The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("Locatapp.sqlite")
var error: NSError? = nil
var failureReason = "There was an error creating or loading the application's saved data."
if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {
coordinator = nil
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
dict[NSLocalizedFailureReasonErrorKey] = failureReason
dict[NSUnderlyingErrorKey] = error
error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
// Replace this with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext? = {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
if coordinator == nil {
return nil
}
var managedObjectContext = NSManagedObjectContext()
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext () {
if let moc = self.managedObjectContext {
var error: NSError? = nil
if moc.hasChanges && !moc.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
}
}
}
这个变量为空
self.lastLocation
你应该调用这个函数
func locationManager (manager: CLLocationManager!, didUpdateLocations locations:[AnyObject]!)
在某处初始化 lastLocation。所以它不会为空
或者您可以更改
var lastLocation: CLLocation! = nil
至此
var lastLocation: CLLocation? = nil
所以当运行这个代码
newManagedObject.latitude = self.lastLocation?.coordinate.latitude
它会跳过这一行，因为 self.lastLocation 是 null 而不是显示 EXC_BAD_INSTRUCTION 错误
我正在学习 swift，我正在阅读名为 "Swift for Dummies" 的书，我尝试按照作者的方法做书中的示例，但我在示例中遇到了问题第四章，大家能帮帮我吗
中的第 51 行出错MasterViewController.swift
newManagedObject.latitude = self.lastLocation.coordinate.latitude
Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) in the output windows is shown fatal error: unexpectedly found nil while unwrapping an Optional value (lldb)
import UIKit
import CoreData
import CoreLocation
class MasterViewController: UITableViewController,
NSFetchedResultsControllerDelegate,
CLLocationManagerDelegate
{
var detailViewController: DetailViewController? = nil
var managedObjectContext: NSManagedObjectContext? = nil
let locationManager = CLLocationManager()
var lastLocation: CLLocation! = nil
override func awakeFromNib() {
super.awakeFromNib()
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.navigationItem.leftBarButtonItem = self.editButtonItem()
let addButton = UIBarButtonItem(barButtonSystemItem: .Add, target: self, action: "insertNewObject:")
self.navigationItem.rightBarButtonItem = addButton
self.startSignificantChangeUpdates()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func insertNewObject(sender: AnyObject) {
let context = self.fetchedResultsController.managedObjectContext
let entity = self.fetchedResultsController.fetchRequest.entity!
let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName("Event", inManagedObjectContext: context) as! Event
// If appropriate, configure the new managed object.
// Normally you should use accessor methods, but using KVC here avoids the need to add a custom class to the template.
newManagedObject.latitude = self.lastLocation.coordinate.latitude
newManagedObject.longitude = self.lastLocation.coordinate.longitude
// Save the context.
var error: NSError? = nil
if !context.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
// MARK: - Segues
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "showDetail" {
if let indexPath = self.tableView.indexPathForSelectedRow() {
let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject
(segue.destinationViewController as! DetailViewController).detailItem = object
}
}
}
// MARK: - Table View
override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
return self.fetchedResultsController.sections?.count ?? 0
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
let sectionInfo = self.fetchedResultsController.sections![section] as! NSFetchedResultsSectionInfo
return sectionInfo.numberOfObjects
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as! UITableViewCell
self.configureCell(cell, atIndexPath: indexPath)
return cell
}
override func tableView(tableView: UITableView, canEditRowAtIndexPath indexPath: NSIndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
override func tableView(tableView: UITableView, commitEditingStyle editingStyle: UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath) {
if editingStyle == .Delete {
let context = self.fetchedResultsController.managedObjectContext
context.deleteObject(self.fetchedResultsController.objectAtIndexPath(indexPath) as! NSManagedObject)
var error: NSError? = nil
if !context.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
}
}
func configureCell(cell: UITableViewCell, atIndexPath indexPath: NSIndexPath) {
let object = self.fetchedResultsController.objectAtIndexPath(indexPath) as! Event
cell.textLabel!.text = "latitude: " + object.latitude.description + " longitude: " + object.longitude.description
}
// MARK: - Fetched results controller
var fetchedResultsController: NSFetchedResultsController {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest()
// Edit the entity name as appropriate.
let entity = NSEntityDescription.entityForName("Event", inManagedObjectContext: self.managedObjectContext!)
fetchRequest.entity = entity
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "timeStamp", ascending: false)
let sortDescriptors = [sortDescriptor]
fetchRequest.sortDescriptors = [sortDescriptor]
// Edit the section name key path and cache name if appropriate.
// nil for section name key path means "no sections".
let aFetchedResultsController = NSFetchedResultsController(fetchRequest: fetchRequest, managedObjectContext: self.managedObjectContext!, sectionNameKeyPath: nil, cacheName: "Master")
aFetchedResultsController.delegate = self
_fetchedResultsController = aFetchedResultsController
var error: NSError? = nil
if !_fetchedResultsController!.performFetch(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
//println("Unresolved error \(error), \(error.userInfo)")
abort()
}
return _fetchedResultsController!
}
var _fetchedResultsController: NSFetchedResultsController? = nil
func controllerWillChangeContent(controller: NSFetchedResultsController) {
self.tableView.beginUpdates()
}
func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
switch type {
case .Insert:
self.tableView.insertSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
case .Delete:
self.tableView.deleteSections(NSIndexSet(index: sectionIndex), withRowAnimation: .Fade)
default:
return
}
}
func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
switch type {
case .Insert:
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
case .Delete:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
case .Update:
self.configureCell(tableView.cellForRowAtIndexPath(indexPath!)!, atIndexPath: indexPath!)
case .Move:
tableView.deleteRowsAtIndexPaths([indexPath!], withRowAnimation: .Fade)
tableView.insertRowsAtIndexPaths([newIndexPath!], withRowAnimation: .Fade)
default:
return
}
}
func controllerDidChangeContent(controller: NSFetchedResultsController) {
self.tableView.endUpdates()
}
/*
// Implementing the above methods to update the table view in response to individual changes may have performance implications if a large number of changes are made simultaneously. If this proves to be an issue, you can instead just implement controllerDidChangeContent: which notifies the delegate that all section and object changes have been processed.
func controllerDidChangeContent(controller: NSFetchedResultsController) {
// In the simplest, most efficient, case, reload the table view.
self.tableView.reloadData()
}
*/
// MARK: CLLocationManagerDelegate Protocol
func startSignificantChangeUpdates () {
if CLLocationManager.authorizationStatus() == CLAuthorizationStatus.NotDetermined {
self.locationManager.requestWhenInUseAuthorization()
}
if CLLocationManager.locationServicesEnabled() {
self.locationManager.delegate = self
self.locationManager.distanceFilter = kCLDistanceFilterNone
self.locationManager.desiredAccuracy = kCLLocationAccuracyBest
self.locationManager.startUpdatingLocation()
self.locationManager.startMonitoringSignificantLocationChanges()
}
}
func locationManager (manager: CLLocationManager!, didUpdateLocations locations:[AnyObject]!) {
self.lastLocation = manager.location
let eventDate = self.lastLocation.timestamp;
let howRecent = eventDate.timeIntervalSinceNow;
}
func locationManager(manager: CLLocationManager!, didFailWithError error: NSError!) {
// need to add code to catch errors
}
}
import UIKit
import MapKit
class DetailViewController: UIViewController {
@IBOutlet var mapView: MKMapView!
@IBOutlet weak var detailDescriptionLabel: UILabel!
var detailItem: AnyObject? {
didSet {
// Update the view.
self.configureView()
}
}
func configureView() {
// Update the user interface for the detail item.
if let detail: AnyObject = self.detailItem {
if let label = self.detailDescriptionLabel {
label.text = detail.valueForKey("timeStamp")!.description
}
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
self.configureView()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
import Foundation
import CoreData
class Event: NSManagedObject {
@NSManaged var latitude: NSNumber
@NSManaged var longitude: NSNumber
@NSManaged var timeStamp: NSDate
}
import UIKit
import CoreData
@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
// Override point for customization after application launch.
let navigationController = self.window!.rootViewController as! UINavigationController
let controller = navigationController.topViewController as! MasterViewController
controller.managedObjectContext = self.managedObjectContext
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:.
// Saves changes in the application's managed object context before the application terminates.
self.saveContext()
}
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: NSURL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.sauer.Locatapp" in the application's documents Application Support directory.
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as! NSURL
}()
lazy var managedObjectModel: NSManagedObjectModel = {
// The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
let modelURL = NSBundle.mainBundle().URLForResource("Locatapp", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
// The persistent store coordinator for the application. This implementation creates and return a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
// Create the coordinator and store
var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("Locatapp.sqlite")
var error: NSError? = nil
var failureReason = "There was an error creating or loading the application's saved data."
if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error) == nil {
coordinator = nil
// Report any error we got.
var dict = [String: AnyObject]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
dict[NSLocalizedFailureReasonErrorKey] = failureReason
dict[NSUnderlyingErrorKey] = error
error = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
// Replace this with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext? = {
// Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
let coordinator = self.persistentStoreCoordinator
if coordinator == nil {
return nil
}
var managedObjectContext = NSManagedObjectContext()
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext () {
if let moc = self.managedObjectContext {
var error: NSError? = nil
if moc.hasChanges && !moc.save(&error) {
// Replace this implementation with code to handle the error appropriately.
// abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
}
}
}
这个变量为空
self.lastLocation
你应该调用这个函数
func locationManager (manager: CLLocationManager!, didUpdateLocations locations:[AnyObject]!)
在某处初始化 lastLocation。所以它不会为空
或者您可以更改
var lastLocation: CLLocation! = nil
至此
var lastLocation: CLLocation? = nil
所以当运行这个代码
newManagedObject.latitude = self.lastLocation?.coordinate.latitude
它会跳过这一行，因为 self.lastLocation 是 null 而不是显示 EXC_BAD_INSTRUCTION 错误