ios - 将对象添加到枚举给我错误

Question

我有一个enum，以及一个指向enum中某个对象的变量。

enum Collection {
    case First, Second, Third, Fourth
}
var myCollection = Collection.Second

我想将 myCollection 传递给 NSUserDefaults。这是我所做的:(我希望 viewDidLoad 是放置它的正确位置。)

override func viewDidLoad() {
    super.viewDidLoad()

    // Save the sort by NSUserDefualt
    let defaults = NSUserDefaults.standardUserDefaults()
    defaults.setObject(self.myCollection, forKey: "myKey")
}

在最后一行，我收到以下错误:

Cannot invoke 'setObject' with an argument list of type '(myViewController.Collection, forKey: String)'

我做错了什么，我该如何解决？

更新

这有意义吗？

let defaults = NSUserDefaults.standardUserDefaults()
let defaultRawValue = defaults.integerForKey("myKey")
if defaultRawValue != nil {
    defaults.setInteger(myCollection.rawValue, forKey: "myKey")
} else {
    defaults.setInteger(1, forKey: "myKey")
}
myCollection = Collection(rawValue: defaultRawValue)!

Answer 1

NSUserDefaults 只能取PropertyList: https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/PropertyLists/AboutPropertyLists/AboutPropertyLists.html

尝试

enum Collection:Int{
        case First=1, Second, Third, Fourth
}
var myCollection = Collection.Second

override func viewDidLoad() {
        super.viewDidLoad()

        let defaults = NSUserDefaults.standardUserDefaults()
        let defaultRawValue = defaults.integerForKey("myKey")
        if defaultRawValue > 0{
            myCollection = Collection(rawValue: defaultRawValue)!
        }
        else
        {
            defaults.setInteger(1, forKey: "myKey")
            myCollection = Collection(rawValue: 1)
        }
}