无法加载课堂警告?

时间:2015-05-08 16:28:20

标签: ios swift core-data

我正在制作一个sprite kit游戏,需要保存三个整数:currentLevel,maxLevelReached和highScore。我也想对iCloud实施这些,但这对我来说是另一个步骤,首先我想弄清楚我现在遇到的问题。基本上,我正在尝试使用核心数据来存储它们。在我的app委托中,我添加了以下内容(基本上我创建了新项目并复制了核心数据代码)

    // 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("GameState", withExtension: "momd")!
    return NSManagedObjectModel(contentsOfURL: modelURL)!
    }()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator? = {
    var coordinator: NSPersistentStoreCoordinator? = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.URLByAppendingPathComponent("APPNAME.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)
        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) {
            // 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()
        }
    }
}

当我这样做时,我创建了我的数据模型(File-> new-> CoreData-> Data model)并将其命名为GameState。然后我创建了名为CurrentLevel的实体,并添加了Int16类型的属性并命名为currentLevel。我创建了类Appname.CurrentLevel的实体。然后,在我的游戏场景中,我添加了以下属性:

var currentLevel = [NSManagedObject]()
var levelToShow: Int16!

并创建了这两个函数来处理核心数据。

    //Handling the fetching from the CoreData
func fetchTheStuff() {

    //1
    let appDelegate =
    UIApplication.sharedApplication().delegate as! AppDelegate

    let managedContext = appDelegate.managedObjectContext!

    //2
    let fetchRequest = NSFetchRequest(entityName:"CurrentLevel")

    //3
    var error: NSError?

    let fetchedResults =
    managedContext.executeFetchRequest(fetchRequest,
        error: &error) as? [NSManagedObject]

    if let results = fetchedResults {
        currentLevel = results
        println(currentLevel)
    } else {
        println("Could not fetch \(error), \(error!.userInfo)")
    }

}


//Handling the saving

func saveCurrentLevel(cLevel: Int16){

    let appDelegate =
    UIApplication.sharedApplication().delegate as! AppDelegate

    let managedContext = appDelegate.managedObjectContext!

    let entity =  NSEntityDescription.entityForName("CurrentLevel",
        inManagedObjectContext:
        managedContext)

    let curLevel = NSManagedObject(entity: entity!,
        insertIntoManagedObjectContext:managedContext)

    curLevel.setValue(name, forKey: "currentLevel")

    var error: NSError?
    if !managedContext.save(&error) {
        println("Could not save \(error), \(error?.userInfo)")
    }

}

正如您所看到的,fetch功能仍处于测试阶段(我只是打印结果)。如果我第一次使用应用程序时获取它,它会给我一个空字符串,因为它应该是。但是,如果我尝试使用保存功能保存数字然后获取内容,则日志屏幕会给出以下警告:

CoreData:警告:无法为实体“CurrentLevel”加载名为“appname.CurrentLevel”的类。找不到类,而是使用默认的NSManagedObject。

知道我想要实现的功能,看到我尝试使用的方法,有没有人知道如何解决我的问题?

P.S。此外,似乎这整个核心数据的内容非常复杂,即使我阅读了很多关于它的内容,我也很难掌握它是如何工作的。因此,如果有人建议降低复杂性以获得相同的结果(因此,不使用任何功能),那么提示非常受欢迎。

1 个答案:

答案 0 :(得分:0)

回答最初的问题 请确保为您的Coredata模型生成正确的类,突出显示您的实体,然后选择编辑器 - >创建NSObject 子类