我修改你一个核心数据应用程序添加二送样板核心数据栈代码NSPersistentStore
S到NSPersistentStoreCoordinator
而不是一个。
// MARK: - Core Data stack
lazy var applicationDocumentsDirectory: NSURL = {
let urls = NSFileManager.defaultManager().URLsForDirectory(.DocumentDirectory, inDomains: .UserDomainMask)
return urls[urls.count-1] as NSURL
}()
lazy var managedObjectModel: NSManagedObjectModel = {
let modelURL = NSBundle.mainBundle().URLForResource("DB", withExtension: "momd")!
return NSManagedObjectModel(contentsOfURL: modelURL)!
}()
lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
var error: NSError? = nil
let firstStoreURL = self.applicationDocumentsDirectory.URLByAppendingPathComponent("first-store.sqlite")
if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: firstStoreURL, options: nil, error: &error) == nil {
coordinator = nil
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
let secondStoreURL = self.applicationDocumentsDirectory.URLByAppendingPathComponent("second-store.sqlite")
if coordinator!.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: secondStoreURL, options: nil, error: &error) == nil {
coordinator = nil
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
return coordinator
}()
lazy var managedObjectContext: NSManagedObjectContext? = {
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) {
NSLog("Unresolved error \(error), \(error!.userInfo)")
abort()
}
}
}
我需要添加时指定商店NSManagedObject
对象,如下面。
let someObject = NSManagedObject(entity: "someEntity", insertIntoManagedObjectContext: context)
context.assignObject(someObject, toPersistentStore: <store instance>)
并指定我需要从这样获取数据的存储。
let entityDescription = NSEntityDescription.entityForName("someEntity", inManagedObjectContext: context)
let fetchRequest = NSFetchRequest()
fetchRequest.entity = entityDescription
fetchRequest.affectedStores = [<store instance>]
我的问题是如何获得这些参考NSPersistentStore
在AppDelegate中创建S'
只是要清楚,我已经知道怎么去的AppDelegate中自身的引用。
let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate
这是获得NSPersistentStore
部分就是我卡住了。
我试图创建它作为AppDelegat这样一个单独的属性,但我不知道该怎么称呼它/从添加它persistentStoreCoordinator
。
var firstStore: NSPersistentStore {
var store: NSPersistentStore!
if let coordinator = persistentStoreCoordinator {
let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("first-store.sqlite")
var error: NSError?
store = coordinator.addPersistentStoreWithType(NSSQLiteStoreType, configuration: nil, URL: url, options: nil, error: &error)!
}
return store
}
此外,每当我把这个属性,是不是一家商店的新实例添加到协调?