ios – NSManagedObject无法符合Swift中的协议

我需要一个NSManagedobject和一个常规NSObject的共享接口.在 Objective-c中,我可以使用协议来实现这一目标.但是在Swift中我得到了这个运行时错误.任何方案？提前致谢！

协议产品{
var code：String {get set}
var sp：String {get set}
}

class Stock: NSManagedobject,Product {

@NSManaged var code: String
@NSManaged var sp: String

}

错误：架构i386的未定义符号：
“__TFC11YellowPages5Stockg2spSS”,引自：
Stock.o中的__TFC11YellowPages5Stockm2spSS
“__TFC11YellowPages5Stockg4codeSS”,引自：
Stock.o中的__TFC11YellowPages5Stockm4codeSS
ld：找不到架构i386的符号
clang：错误：链接器命令失败,退出代码为1(使用-v查看调用)

解决方法

这对我有用.亲自尝试一下,看看它是否有效：

class MyEntity: NSManagedobject {

    @NSManaged var testAttribute: String
}

@objc
protocol MyProtocol {

    var testAttribute: String { get set }
}

extension MyEntity: MyProtocol { }

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate
        let myContext = appDelegate.managedobjectContext!
        let entity: MyEntity = NSEntityDescription.insertNewObjectForEntityForName("MyEntity",inManagedobjectContext: myContext) as MyEntity
        foo(entity)
        println(entity.testAttribute)
    }

    func foo(var object: MyProtocol) {
        object.testAttribute = "bar"
    }
}

下面也有用,但我认为以上是更好的方法：

@objc
protocol MyProtocol {

    var testAttribute: String { get set }
}

class MyEntity: NSManagedobject,MyProtocol {

    @NSManaged var testAttribute: String
}

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        let appDelegate = UIApplication.sharedApplication().delegate as AppDelegate
        let myContext = appDelegate.managedobjectContext!
        let entity: MyEntity = NSEntityDescription.insertNewObjectForEntityForName("MyEntity",inManagedobjectContext: myContext) as MyEntity
        foo(entity)
        println(entity.testAttribute)
    }

    func foo(var object: MyProtocol) {
        object.testAttribute = "bar"
    }
}