arrays - 从核心数据中获取数据

Question

我是 Swift 的新手，正在开始学习 Core Data，但我遇到了一个问题。我无法从我的 Core Data 数据库中获取数据。我想在核心数据中使用 Firebase 下载出于某种原因，数据显示来自 Firebase 而不是来自数据库。如何从数据库中提取数据？

这是我的 Controller :

    class InfoProfileViewController: UIViewController {

    @IBOutlet weak var imageProfile: UIImageView!

    @IBOutlet weak var nickProfile: UILabel!

    @IBOutlet weak var emailProfile: UILabel!

    @IBOutlet weak var numberProfile: UILabel!

    var userData: UserData?

    var managedObjextContext:NSManagedObjectContext!

    var infoProfile = [User]()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.userData = UserData(user: (FIRAuth.auth()?.currentUser)!)
        managedObjextContext = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
        showAllUsers()
    }

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

   private func loadData(){
        let presentRequest:NSFetchRequest<User> = User.fetchRequest()

        do {
            infoProfile = try managedObjextContext.fetch(presentRequest)
            print()

        }catch {
            print("Could not load data from database \(error.localizedDescription)")
        }
    }

    private func showAllUsers() {
        FIRDatabase.database().reference().child(UserData.DRIVERS_LOCATION_KEY).observeSingleEvent(of: FIRDataEventType.value, with: { (snapshot) in

            let userItem = User(context: self.managedObjextContext)

            if self.emailProfile.text != ""{

                userItem.name = (self.userData?.nick)!
                userItem.number = (self.userData?.number)!
                userItem.avataURL = (self.userData?.avatarUrl)!
                userItem.email = FIRAuth.auth()?.currentUser?.email!

                do {
                    try self.managedObjextContext.save()
                    self.loadData()
                    print("Good save")
                }catch {
                    print("Could not save data \(error.localizedDescription)")
                }
            }
       //this my problem    
            do {
                for profil in self.infoProfile{
                    self.emailProfile.text = profil.email
                    print(profil.email as Any)
                    self.nickProfile.text = profil.name
                    self.numberProfile.text = profil.number
                }
            }

        })
    }
}

我的模型:

Answer 1

Firebase 不只是填充您的 Core Data 数据库——您必须自己完成。

您可能想要研究更自动化的 Firebase 离线功能(并且不使用 CoreData):https://www.firebase.com/docs/ios/guide/offline-capabilities.html