NSManagedObject错误

我现在开始学习iOS的核心数据。 我目前得到致命的错误：意外地发现零，同时展开下面的代码行上的可选值 。 我一直在YouTube和其他地方听过讲座，也看了一下他们的代码，但是却不知道这个错误背后的原因。 如果有人能给我一个概述，这将是非常有帮助的。 目前在我的代码中，我只是从实体分配值，没有提取。

应用程序代表：

lazy var applicationDocumentsDirectory: NSURL = { // The directory the application uses to store the Core Data store file. This code uses a directory named "com.alakh.singh.okejhbs" in the application's documents Application Support directory. let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask) return urls[urls.count-1] }() 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("ActivityMonitor", withExtension: "momd")! return NSManagedObjectModel(contentsOfURL: modelURL)! }() lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = { // The persistent store coordinator for the application. This implementation creates and returns 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 let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel) let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("SingleViewCoreData.sqlite") var failureReason = "There was an error creating or loading the application's saved data." do { try coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil) } catch { // 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 as NSError let wrappedError = 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 \(wrappedError), \(wrappedError.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 var managedObjectContext = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType) managedObjectContext.persistentStoreCoordinator = coordinator return managedObjectContext }() // MARK: - Core Data Saving support func saveContext () { if managedObjectContext.hasChanges { do { try managedObjectContext.save() } catch { // 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. let nserror = error as NSError NSLog("Unresolved error \(nserror), \(nserror.userInfo)") abort() } } } } 

视图控制器：

  @IBAction func cofirmLogin(sender: UIButton) { let oct = ((UIApplication.sharedApplication().delegate as? AppDelegate)?.managedObjectContext) var userNameValue = NSEntityDescription.insertNewObjectForEntityForName("LoginInformation", inManagedObjectContext: oct!) as! LoginInformation userNameValue.loginUserName = loginUserName.text! userNameValue.loginPin = Int(loginPin.text!)! userNameValue = loginInfo saveContext(oct!) } func saveContext (context : NSManagedObjectContext) { if context.hasChanges { do { try context.save() } catch { let nserror = error as NSError NSLog("Unresolved error \(nserror), \(nserror.userInfo)") } } } } 

Answer 1

也许有些东西不像懒惰variables预期的那样工作。 你可以像这样重构你的托pipe对象的上下文。

 var managedObjectContext: NSManagedObjectContext { get { if _managedObjectContext == nil { let coordinator = self.persistentStoreCoordinator let moc = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType) moc.persistentStoreCoordinator = coordinator _managedObjectContext = moc } return _managedObjectContext! } } var _rootContext: NSManagedObjectContext? 

此外，请确保应用程序委托按预期返回（也许分解成几行并检查debugging器）。