Question

你好我在Swift中遇到了核心数据的问题，这并没有显示错误，但是当我认为它应该返回时，它也不会打印任何内容＃Joe;＆＃39; Joe＆＃39; +＆＃39;传递＆＃39;在控制台。有人可以帮忙吗？

import UIKit
import CoreData

class ViewController: UIViewController {



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

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

    var context:NSManagedObjectContext = appDel.managedObjectContext

    var newUser = NSEntityDescription.insertNewObjectForEntityForName("Users", inManagedObjectContext: context) as NSManagedObject

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

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

    do {
     try context.save()
    } catch let error {
        print("Couldn't save user data")
        print(error)
    }

    let request = NSFetchRequest(entityName: "Users")
        request.returnsObjectsAsFaults = false

    do {
        var results = try context.executeFetchRequest(request)
        results = results as! [NSManagedObject]
        if results.count > 0 {
        for results in results {
            print(results)
            }}
    } catch let error as NSError {
        print(error)
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}


}

Answer 1

您应该创建自己的coredata类（作为NSManagedObject的子类），然后从该类创建数组。
准确指定要打印的内容。在你的情况下

newUser.username

Answer 2

我终于意识到我的问题是什么，我实际上并没有将实体重命名为'用户'我将其保留为'实体'所以当我做的时候

let newUser = NSEntityDescription.insertNewObjectForEntityForName("Users", inManagedObjectContext: context) as NSManagedObject 
let request = NSFetchRequest(entityName: "Users")

我应该已经用“实体”替换了两个用户，现在我已经解决了我的问题，谢谢我猜你的帮助！

Coredata迅速

2 个答案: