【发布时间】：2014-10-07 03:26:24
【问题描述】：
我一直在尝试使用 CoreData 和 Swift 在关系中添加对象。我很茫然，我不明白为什么我的代码不起作用。我正在尝试将“事件”添加到“团队”。我找不到接受的答案（应该有效）和我的代码（无效）之间的区别。
Teams.swift：
import Foundation
import CoreData
class Teams: NSManagedObject {
@NSManaged var teamName: String
@NSManaged var matches: NSSet
}
extension Teams {
func addEventToTeam(event:Event) {
//self.mutableSetValueForKeyPath("matches").addObject(event)
var matchez: NSMutableSet
matchez = self.mutableSetValueForKey("matches")
matchez.addObject(event)
//var manyRelation = self.valueForKeyPath("matches") as NSMutableSet
//manyRelation.addObject(event)
}
func getTeamName() -> String {
return teamName
}
}
调用代码（从配置视图）：
import UIKit
import CoreData
class DetailViewController: UIViewController, NSFetchedResultsControllerDelegate {
var managedObjectContext: NSManagedObjectContext? = nil
@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: Event = (self.detailItem as? Event) {
//if let detail: AnyObject = self.detailItem {
if let label = self.detailDescriptionLabel {
label.text = detail.valueForKey("timeStamp").description
self.insertNewObject(self);
label.text = String(detail.getNumberOfTeams())
//detail.getTeams().
var hej: Array<Teams>
hej = detail.getTeams()
label.text = "tjosan"
for tmpTeam : Teams in hej {
label.text = label.text + ", " + tmpTeam.getTeamName()
}
}
}
if true {
}
}
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.
}
var fetchedResultsController: NSFetchedResultsController {
if _fetchedResultsController != nil {
return _fetchedResultsController!
}
let fetchRequest = NSFetchRequest()
// Edit the entity name as appropriate.
let team = NSEntityDescription.entityForName("Teams", inManagedObjectContext: self.managedObjectContext)
fetchRequest.entity = team
// Set the batch size to a suitable number.
fetchRequest.fetchBatchSize = 20
// Edit the sort key as appropriate.
let sortDescriptor = NSSortDescriptor(key: "teamName", 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 insertNewObject(sender: AnyObject) {
let context = self.fetchedResultsController.managedObjectContext
let team = self.fetchedResultsController.fetchRequest.entity
let newManagedObject = NSEntityDescription.insertNewObjectForEntityForName(team.name, inManagedObjectContext: context) as Teams
// 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.setValue("Lagur Namnurk", forKey: "teamName")
newManagedObject.addEventToTeam(self.detailItem as Event)
// 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()
}
}
}
错误信息：
2014-08-13 18:38:46.651 Score Calculator 2[10538:829319] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSSet intersectsSet:]: set argument is not an NSSet'
*** First throw call stack:
(
0 CoreFoundation 0x00000001028a53e5 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x00000001043b8967 objc_exception_throw + 45
2 CoreFoundation 0x000000010280fc6c -[NSSet intersectsSet:] + 940
3 Foundation 0x0000000102d0c4a6 NSKeyValueWillChangeBySetMutation + 156
4 Foundation 0x0000000102c804fa NSKeyValueWillChange + 386
5 Foundation 0x0000000102d0c3fb -[NSObject(NSKeyValueObserverNotification) willChangeValueForKey:withSetMutation:usingObjects:] + 310
6 CoreData 0x00000001024178d7 -[NSManagedObject(_NSInternalMethods) _includeObject:intoPropertyWithKey:andIndex:] + 551
7 CoreData 0x0000000102418294 -[NSManagedObject(_NSInternalMethods) _maintainInverseRelationship:forProperty:forChange:onSet:] + 276
8 CoreData 0x0000000102416ef2 -[NSManagedObject(_NSInternalMethods) _didChangeValue:forRelationship:named:withInverse:] + 562
9 Foundation 0x0000000102c835d6 NSKeyValueNotifyObserver + 356
10 Foundation 0x0000000102c827fd NSKeyValueDidChange + 466
11 Foundation 0x0000000102d0c7ee -[NSObject(NSKeyValueObserverNotification) didChangeValueForKey:withSetMutation:usingObjects:] + 118
12 CoreData 0x00000001024180b0 -[NSManagedObject didChangeValueForKey:withSetMutation:usingObjects:] + 80
13 CoreData 0x000000010242fa11 -[_NSNotifyingWrapperMutableSet addObject:] + 161
编辑：一些澄清。 Teams 和 Event 具有多对多的无序关系。
【问题讨论】：
-
这是苹果的bug:a good explain in stackoverflow