请知道有人告诉我我做错了什么?
申请崩溃:
CoreData:错误:无法在NSManagedObject类上调用指定的初始化程序' xyz.Topics'
我需要有关JSON解析和存储到CoreData的帮助。
import CoreData
class Topics: NSManagedObject {
@NSManaged var id: NSNumber
@NSManaged var name: NSString
@NSManaged var price: NSNumber
@NSManaged var subject_id: NSNumber
@NSManaged var created_at: NSDate
@NSManaged var updated_at: NSDate
@NSManaged var deleted_at: NSDate
func parseData (){
var endpoint = NSURL(string: "......")
var data = NSData(contentsOfURL: endpoint!)
let json = NSJSONSerialization.JSONObjectWithData(data!, options: NSJSONReadingOptions.MutableContainers, error: nil) as NSDictionary
var items = [[String:AnyObject]()]
var item:AnyObject
for (var i = 0; i < json["topics"]!.count; i++) {
items.append([String:AnyObject]())
item = json["topics"]![i] as NSDictionary
items[i]["id"] = item["id"] as? NSNumber
items[i]["name"] = item["name"] as? String
items[i]["price"] = item["price"] as? NSNumber
items[i]["subject_id"] = item["subject_id"] as? NSNumber
items[i]["deleted_at"] = item["deleted_at"] as? NSDate
items[i]["created_at"] = item["created_at"] as? NSDate
items[i]["updated_at"] = item["updated_at"] as? NSDate
//Save
var addTopicItem = NSEntityDescription.insertNewObjectForEntityForName("Topics", inManagedObjectContext: managedObjectContext!) as NSManagedObject
addTopicItem.setValue(items[i]["id"], forKey: "id")
addTopicItem.setValue(items[i]["name"], forKey: "name")
addTopicItem.setValue(items[i]["price"], forKey: "price")
addTopicItem.setValue(items[i]["subject_id"], forKey: "subject_id")
addTopicItem.setValue(items[i]["deleted_at"], forKey: "deleted_at")
addTopicItem.setValue(items[i]["created_at"], forKey: "created_at")
addTopicItem.setValue(items[i]["updated_at"], forKey: "updated_at")
managedObjectContext!.save(nil)
}
}
}
的AppDelegate:
// 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 "xyz" 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("xyz", 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("xyz.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()
}
}
}