Question

我想使用Core数据在今天的扩展程序中显示照片。但是，实体是空的。我对此一无所知。

这就是我正在做的事情：

在两个目标（应用和扩展程序）中添加应用组
检查xcdatamodeld中的目标成员资格。

创建CoreDataStack类，以便在今天的扩展中使用Core数据。

class CoreDataStack {

private init() {

NotificationCenter.default.addObserver(self,
                                       selector: #selector(mainContextChanged(notification:)),
                                       name: .NSManagedObjectContextDidSave,
                                       object: self.managedObjectContext)

NotificationCenter.default.addObserver(self,
                                       selector: #selector(bgContextChanged(notification:)),
                                       name: .NSManagedObjectContextDidSave,
                                       object: self.backgroundManagedObjectContext)
}
static let sharedStack = CoreDataStack()
var errorHandler: (Error) -> Void = {_ in }

@available(iOS 10.0, *)
lazy var persistentContainer: NSPersistentContainer = {

    let container = NSPersistentContainer(name: "name")
    container.loadPersistentStores(completionHandler: { [weak self](storeDescription, error) in
        if let error = error {
            NSLog("CoreData error \(error), \(error._userInfo)")
            self?.errorHandler(error)
        }
    })
    return container }()

@available(iOS 10.0, *)
lazy var viewContext: NSManagedObjectContext = {
return self.persistentContainer.viewContext
}()

@available(iOS 10.0, *)
func performBackgroundTask(_ block: @escaping (NSManagedObjectContext) -> Void) {
 self.persistentContainer.performBackgroundTask(block)
}


deinit {
    NotificationCenter.default.removeObserver(self)
}

lazy var libraryDirectory: URL = {

let urls = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group...")

return urls!

}()



lazy var managedObjectModel: NSManagedObjectModel = {
    let modelURL = Bundle.main.url(forResource: "name", withExtension: "momd")!
    return NSManagedObjectModel(contentsOf: modelURL)!
}()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
let coordinator = NSPersistentStoreCoordinator(managedObjectModel:
    self.managedObjectModel)
let directory = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.kr....")
let urls = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.kr....")!.path
let url = directory!.appendingPathComponent("name.sqlite")

do {
    try coordinator.addPersistentStore(ofType:
        NSSQLiteStoreType,
                                       configurationName: nil,
                                       at: url,
                                       options: nil)
} catch {
    // Report any error we got.
    NSLog("CoreData error \(error), \(error._userInfo)")
    self.errorHandler(error)
}
return coordinator  }()

lazy var backgroundManagedObjectContext: NSManagedObjectContext = {
let coordinator = self.persistentStoreCoordinator
var privateManagedObjectContext = NSManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)
privateManagedObjectContext.persistentStoreCoordinator = coordinator
return privateManagedObjectContext   }()

@available(iOS 9.0, *)
lazy var managedObjectContext: NSManagedObjectContext = {
var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
managedObjectContext.persistentStoreCoordinator = self.persistentStoreCoordinator
return managedObjectContext        }()


@objc func mainContextChanged(notification: NSNotification) {
backgroundManagedObjectContext.perform { [unowned self] in
    self.backgroundManagedObjectContext.mergeChanges(fromContextDidSave: notification as Notification)
    }
} 
@objc func bgContextChanged(notification: NSNotification) {
managedObjectContext.perform{ [unowned self] in
    self.managedObjectContext.mergeChanges(fromContextDidSave: notification as Notification)
        }
    }

func saveContext () {
if #available(iOS 10.0, *) {
    let context = persistentContainer.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() 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
            fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
        }
    }
} else {
    do {
        try managedObjectContext.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()
            }

        }
     }

}

在今天的扩展视图控制器中添加功能

func fetchData() {

let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Quotes")

if #available(iOS 10.0,*) {

    let context = CoreDataStack.sharedStack.viewContext

    do {
        let results = try context.fetch(fetchRequest)

        self.quotes = results as? [Quotes]
        print("result = \(results)")


    } catch let error as NSError {

        print("Could not fetch \(error), \(error.userInfo)")

        return
    }
}else {
    //for ios 9.3~
    let context = CoreDataStack.sharedStack.managedObjectContext

    do {
        let results = try context.fetch(fetchRequest)

        self.quotes = results as? [Quotes]
        print("result = \(results)")


    } catch let error as NSError {

        print("Could not fetch \(error), \(error.userInfo)")

        return
    }
}

for i in self.quotes! {

    let image = UIImage(data: i.img! as Data, scale: 1.0)

    self.quotesImgs.append(image!)
    print("is that really image? \(image)")
    print("app in for in sytax for coredata = \(self.quotesImgs)")



}

print("quotes \(self.quotes)")
}

打印为result = [] / quotes Optional([])

我错过了什么？

使用今日扩展程序

0 个答案: