CoreData - 保存时崩溃

Question

所以，这是我的代码：

ViewController 1：

class ViewSet: UIViewController {

    @IBOutlet var Label_1: UILabel!
    @IBOutlet var Label_2: UILabel!
    @IBOutlet var Text: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

        var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        var moc: NSManagedObjectContext = appDel.managedObjectContext!

        var request = NSFetchRequest(entityName: "TestingCoreData")
        request.returnsObjectsAsFaults = false;

        var results: NSArray = moc.executeFetchRequest(request, error: nil)!

        if (results.count > 0) {
            var res = results[0] as! NSManagedObject
            Label_1.text = res.valueForKey("label_1") as? String
            Label_2.text = res.valueForKey("label_2") as? String
            Text.text = res.valueForKey("text") as? String

        } else {
            println("No results found")
        }


    }
}

ViewController 2：

import UIKit
import CoreData

class Label_1: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
    }


    @IBOutlet var Label_1: UITextField!

    @IBAction func addLabel_1(sender: AnyObject) {

        var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        var moc: NSManagedObjectContext = appDel.managedObjectContext!

        var label1 = NSEntityDescription.insertNewObjectForEntityForName("TestingCoreData", inManagedObjectContext: moc) as! NSManagedObjectContext
        label1.setValue("\(Label_1.text)", forKey: "label_1")

        moc.save(nil)
        println("Object saved")

        performSegueWithIdentifier("toLabel2", sender: self)

    }
}

ViewController 3：

import UIKit
import CoreData

class Label_2: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBOutlet var Label_2: UITextField!

    @IBAction func add(sender: AnyObject) {

        var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        var moc: NSManagedObjectContext = appDel.managedObjectContext!

        var label2 = NSEntityDescription.insertNewObjectForEntityForName("TestingCoreData", inManagedObjectContext: moc) as! NSManagedObjectContext
        label2.setValue("\(Label_2.text)", forKey: "label_2")

        moc.save(nil)
        println("Object saved")

        performSegueWithIdentifier("toText", sender: self)
    }
}

ViewController 4：

import UIKit
import CoreData

class Text: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
}

    @IBOutlet var Text: UITextView!

    @IBAction func done(sender: AnyObject) {

        var appDel: AppDelegate = (UIApplication.sharedApplication().delegate as! AppDelegate)
        var moc: NSManagedObjectContext = appDel.managedObjectContext!

        var text = NSEntityDescription.insertNewObjectForEntityForName("TestingCoreData", inManagedObjectContext: moc) as! NSManagedObjectContext
        text.setValue("\(Text.text)", forKey: "text")

        moc.save(nil)
        println("Object saved")

        navigationController?.popToRootViewControllerAnimated(true)

    }

}

我相信代码非常简单。我正在尝试通过CoreData学习，但我似乎无法正常使用它。

当我按下add以转到第3个视图控制器时，它崩溃了：

任何人都可以帮助我吗？我是这个东西的新手！提前致谢