问题描述
Xcode 6有很多错误。但我不知道这是否是一个错误。这可能不是因为这是我刚刚学习的东西。
Xcode 6 has had a ton of bugs. But I'm not quite sure if this is a bug or not. It might not be since this is something I'm just now learning.
我的问题是，任何时候我试图实例化我的NSManagedObject的子类，我没有选项来传递构造函数的实体：NSEntityDescription 和 NSManagedContext：insertIntoManagedContext 参数，Xcode说Extra Argumententity' in call
My issue is, any time I try to instantiate my subclass of NSManagedObject, I do not have the option to pass the entity: NSEntityDescription and NSManagedContext: insertIntoManagedContext argument to the constructor, Xcode says "Extra Argument 'entity' in call"
我从头开始创建了一个新的Xcode项目，只是为了看看是否可以在一个更小，最小的项目中重新创建问题。
I created a new Xcode project from scratch, just to see if I could re-create the problem in a smaller, minimal project.
ToDoList.Item设置为数据模型检查器中的 Item 实体类。
ToDoList.Item is set as the Item entity class in the Data Model Inspector.
下面是代码：
override func viewDidLoad() {
super.viewDidLoad()
let appDel: AppDelegate = UIApplication.sharedApplication().delegate as AppDelegate
let context: NSManagedObjectContext = appDel.managedObjectContext!
let ent = NSEntityDescription.entityForName("Item", inManagedObjectContext: context)!
//compiler complains here
var item = Item(entity: ent, insertIntoManagedObjectContext: context)!
}
这是子类：
import UIKit
import CoreData
class Item: NSManagedObject {
@NSManaged var title: String
@NSManaged var completed: Bool
}
全部帮助被赞赏。
推荐答案
刚刚遇到同样的问题：
Just came across the same problem: Constructor for core data entity not available
显然，我们必须实现
init(entity: NSEntityDescription, insertIntoManagedObjectContext context, NSManagedObjectContext?)
方法。所以只需添加
override init(entity: NSEntityDescription, insertIntoManagedObjectContext context: NSManagedObjectContext?) {
super.init(entity: entity, insertIntoManagedObjectContext: context)
}
这篇关于无法实例化NSManagedObject的子类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！