Ich erhalte diesen Wrapping-Fehler, wenn ich meinen abgerufenen verwalteten Objekt-Core-Datencode implementiere. Derzeit erhalten fatal error: unexpectedly found nil while unwrapping an Optional value
. Was mache ich falsch?Schwerwiegender Fehler: beim Entpacken unerwartet ein Nullwert gefunden Optionaler Wert - Core Data (Swift)
Viewcontroller:
func saveRun() {
// 1
let savedRun = NSEntityDescription.insertNewObject(forEntityName: "Run", into: managedObjectContext!) as! Run
savedRun.distance = NSNumber(value: distance)
savedRun.duration = (NSNumber(value: seconds))
savedRun.timestamp = NSDate() as Date
// 2
var savedLocations = [Location]()
for location in locations {
let savedLocation = NSEntityDescription.insertNewObject(forEntityName: "Location",
into: managedObjectContext!) as! Location
savedLocation.timestamp = (location.timestamp as NSDate) as Date
savedLocation.latitude = NSNumber(value: location.coordinate.latitude)
savedLocation.longitude = NSNumber(value: location.coordinate.longitude)
savedLocations.append(savedLocation)
}
savedRun.locations = NSOrderedSet(array: savedLocations)
run = savedRun
do{
try managedObjectContext!.save()
}catch{
print("Could not save the run!")
}
}
App Delegierter:
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: URL = {
// The directory the application uses to store the Core Data store file. This code uses a directory named "com.zedenem.MarathonRun" in the application's documents Application Support directory.
let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
return urls.last!
}()
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 = Bundle.main.url(forResource: "MarathonRun", withExtension: "momd")!
return NSManagedObjectModel(contentsOf: 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.appendingPathComponent("MarathonRun")
var error: NSError? = nil
var failureReason = "There was an error creating or loading the application's saved data."
do {
try coordinator!.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: nil)
}catch let error as NSError {
coordinator = nil
// Report any error we got.
var dict = [AnyHashable: Any]()
dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data"
dict[NSLocalizedFailureReasonErrorKey] = failureReason
dict[NSUnderlyingErrorKey] = error
print("Error: \(error.domain)")
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(concurrencyType: .mainQueueConcurrencyType)//NSManagedObjectContext()
managedObjectContext.persistentStoreCoordinator = coordinator
return managedObjectContext
}()
// MARK: - Core Data Saving support
func saveContext() {
if let moc = self.managedObjectContext {
if moc.hasChanges{
do{
try moc.save()
}catch let error as NSError{
print("Error: \(error.domain)")
}
}
}
Warum sind 'NSPersistentStoreCoordinator' und' NSManagedObjectContext' optional?Wenn die Erstellung des Koordinators fehlschlägt, erhalten Sie trotzdem einen schwerwiegenden Fehler ('abort()') und die App wird beendet. Beide Instanzen sollen ** nicht optional ** sein. Und die Init-Methode 'init (managedObjectModel' von' NSPersistentStoreCoordinator' gibt auch eine nicht-optionale Instanz zurück. Warum notieren Sie den Typ als optional und verschlechtern ihn? – vadian
Aber was ist hier falsch? –
Vielleicht sagt Ihnen der Compiler. – vadian