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。我正在尝试添加一个＆＃34;事件＆＃34;到了＃34;团队＆＃34;。我找不到接受的答案（应该有效）和我的代码（没有）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()
}
}
}
错误讯息：
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。团队和活动有着多对多，无序的关系。
答案 0 :(得分：11)
YESSS !!我找到了答案！
我在Events.swift类中创建了一个新函数（关系的另一面）。
我写了以下代码：
import Foundation
import CoreData
class Event: NSManagedObject {
@NSManaged var timeStamp: NSDate
@NSManaged var teams: NSSet
}
extension Event {
func addTeamToEvent(team:Teams) {
var teamz = self.mutableSetValueForKey("teams")
teamz.addObject(team)
}
func getNumberOfTeams() -> Int {
return self.teams.count;
}
func getTeams() -> [Teams] {
var tmpsak: [Teams]
tmpsak = self.teams.allObjects as [Teams]
tmpsak = self.teams.allObjects as [Teams]
return tmpsak
}
}
感谢您的建议，我希望这对其他人有所帮助！
在一个有点相关的说明中，几年前发现了一个类似症状的错误（并且似乎仍然存在），当使用有序 many-to时，它会在自动生成的代码中显示出来 - 很多关系。
答案 1 :(得分：1)
如果您使用目标C生成的NSManagedObject子类，它们包含用于添加单个对象的自定义方法 - 我认为这些是经过试验和测试的，并且看起来比目前swift的更好。
理论上，您只需要使用您创建的任何新集来设置新集。一种选择是：
var matchobjs = matches.allObjects as [Event]
matchobjs.append(event)
matches = NSSet(array: matchobjs)
然而，该错误与this post:
非常相似对我来说，看起来像是多情多彩的关系再次发生了什么......