SWIFT 2：核心数据似乎不起作用

Question

我正在学习关于 Swift 的优秀课程，但在 Core Data 方面似乎已经过时了。我想在核心数据中存储用户名和密码，但它似乎没有永久存储任何内容。为什么？

网上大部分教程都过时了。

• 我在创建空项目并创建所需的实体和属性时单击了核心数据选项。

  let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
  
          let context:NSManagedObjectContext = appDel.managedObjectContext!
  

  让 newUser = NSEntityDescription.insertNewObjectForEntityForName("Users", inManagedObjectContext: context)

          newUser.setValue("Rober", forKey: "username")
  
          newUser.setValue("pass", forKey: "password")
  
  
  
  
  
          let request = NSFetchRequest(entityName: "Users")
  
          request.returnsObjectsAsFaults = false
  
          //request.predicate = NSPredicate(format: "username = %@", "kirsten")
  
      var results: [AnyObject]?
          do {
              results = try context.executeFetchRequest(request)
          } catch _ {
              results = nil
          }
  
          if results!.count > 0 {
  
              for result: AnyObject in results! {
  
                  if let username: String = result.valueForKey("username") as? String {
  
                      print(username)
  
                      result.setValue("kirsten", forKey: "username")
  
                      context.deleteObject(result as! NSManagedObject)
  
                      do {
                          try context.save()
                      } catch _ {
                      }
  
                  }
  
              }
  
  
          } else {
  
              print("No results")
  
          }
  

会是什么？是否有任何关于在 swift 2 中处理核心数据的更新教程？ 谢谢

------------------ SOLUTION : Core Data 代码在 Swift 2 上运行良好 -------- ------------ 这一堆代码存储数据并显示它，如果您还想删除数据，只需取消注释行 // context.deleteObject(result as!NSManagedObject)

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate

    let context:NSManagedObjectContext = appDel.managedObjectContext!


    let newUser = NSEntityDescription.insertNewObjectForEntityForName("Users", inManagedObjectContext: context)



    newUser.setValue("Roberto", forKey: "username")

    newUser.setValue("pass", forKey: "password")





    let request = NSFetchRequest(entityName: "Users")

    request.returnsObjectsAsFaults = false

   //     request.predicate = NSPredicate(format: "username = %@", "kirsten")

    var results: [AnyObject]?
    do {
        results = try context.executeFetchRequest(request)
    } catch _ {
        results = nil
    }

    if results!.count > 0 {

        for result: AnyObject in results! {

            if let username: String = result.valueForKey("username") as? String {

                print(username)


              //  result.setValue("Angel", forKey: "username")

            //    context.deleteObject(result as! NSManagedObject)

                do {
                    try context.save()
                } catch _ {
                }

            }

            if let password: String = result.valueForKey("password") as? String {

                print(password)


                //  result.setValue("Angel", forKey: "username")

                //    context.deleteObject(result as! NSManagedObject)

                do {
                    try context.save()
                } catch _ {
                }

            }

        }


    } else {

        print("No results")

    }



}

Answer 1

这是我的工作代码片段

使用 Swift 2.0 在 Core Data 中保存用户详细信息

//  Created by Ramdhan on 06/11/15.

import UIKit
import CoreData

class RegisterViewController: UIViewController {

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

    @IBOutlet weak var name: UITextField!
    @IBOutlet weak var password: UITextField!
    @IBOutlet weak var rePassword: UITextField!
    @IBOutlet weak var cell: UITextField!

    // MARK: - Controller life cycle stack

    override func viewDidLoad() {
        super.viewDidLoad()

    }

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



    //MARK: Store user info on Device DB

    func saveUserInfoOnDB()
    {

        let entityObj =
        NSEntityDescription.entityForName("User",
            inManagedObjectContext: managedObjectContext)
        let userObj = User(entity: entityObj!,
            insertIntoManagedObjectContext: managedObjectContext)

        userObj.username = name.text
        userObj.password = password.text
        userObj.email_cell = cell.text

        if managedObjectContext.hasChanges
        {
            do
            {
                try managedObjectContext.save()
                let error: NSError? = nil

                if let err = error
                {
                    print("%@",err.localizedFailureReason)
                    print("Could not saved \(error), \(err.userInfo)")

                } else {
                    name.text = ""
                    password.text = ""
                    cell.text = ""
                    print("User info Saved")

                    performSegueWithIdentifier("loadManageAccountSegue", sender: nil)
                }
            }
            catch
            {
                let nserror = error as NSError
                NSLog("Unresolved error \(nserror), \(nserror.userInfo)")
                abort()
            }
        }
    }
}

我的实体快照