【发布时间】：2016-07-26 06:22:09
【问题描述】：
在我的应用程序中，我使用了一个类（比如 CoredataHandler.swift）来存储和检索对象。我关注了this tutorials。我使用了策略 2：父/子托管对象上下文。 但是对象不存储在核心数据中。我没有使用 NSOperation，而是使用了普通的类对象。
class CoreDataHandler: NSObject {
//static var sharedInstance:CoreDataHandler = CoreDataHandler()
var privateManagedObjectContext:NSManagedObjectContext?
var mainManagedObjectContext:NSManagedObjectContext?
override init() {
print("core data handler constructor called")
super.init()
let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let privateManagedObjectContextlocal = NSManagedObjectContext(concurrencyType: .MainQueueConcurrencyType)
privateManagedObjectContextlocal.parentContext = appDelegate.managedObjectContext
self.privateManagedObjectContext = privateManagedObjectContextlocal
self.mainManagedObjectContext = appDelegate.managedObjectContext
let notificationCenter = NSNotificationCenter.defaultCenter()
notificationCenter.addObserver(self, selector: #selector(CoreDataHandler.managedObjectContextDidSave(_:)), name: NSManagedObjectContextDidSaveNotification, object: privateManagedObjectContext)
}
private func insertData(entityName:String,dataDictionary:Dictionary<String, AnyObject?>){
synced(self) { () -> () in
// let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
let entityDescription = NSEntityDescription.entityForName(entityName, inManagedObjectContext: self.privateManagedObjectContext!)
let newPerson = NSManagedObject(entity: entityDescription!, insertIntoManagedObjectContext: self.privateManagedObjectContext!)
for (myKey, myVal) in dataDictionary {
if myVal is Int {
if let result_number = myVal as? NSNumber
{
let result_string = "\(result_number)"
newPerson.setValue(result_string, forKey: myKey)
}
}else{
newPerson.setValue(myVal, forKey: myKey)
}
}
//print("insertData",newPerson)
do {
if ((self.privateManagedObjectContext?.hasChanges) != nil){
try self.privateManagedObjectContext!.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()
}
}
}
// MARK: - Insert
func insertOfferObjects(arrOffer : Array<FoodItem>?) {
synced(self) { () -> () in
//Step1: Adding Offer Items
if let _ = arrOffer {
var foodArr:Array<NSManagedObject> = Array()
for foodObj : FoodItem in arrOffer! {
let offerItemEntity = self.createFoodItemEntity(foodObj)
foodArr.append(offerItemEntity)
}
self.insertData("OfferCategory", dataDictionary: ["categoryTitle": "Offers", "foodItemArray": NSOrderedSet(array: foodArr)])
}
}
}
值不存储在核心数据中。请给我最好的方法。
已编辑：更新 :: 来自答案，需要在子上下文时保存父级 已保存
self.privateManagedObjectContext?.performBlockAndWait({
if ((self.privateManagedObjectContext?.hasChanges) != nil){
do {
print("It has changes...............")
try self.privateManagedObjectContext!.save()
self.mainManagedObjectContext?.performBlock({
do {
try self.mainManagedObjectContext!.save()
}catch{
}
})
}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()
}
}
})
【问题讨论】：
标签： ios objective-c swift core-data core-data-migration