swift之使用 NSKeyedArchiver 保存并加载回来的对象为零

我使用以下代码保存自定义对象 Bottle

class Bottle: NSObject, NSCoding { 
 
    let id: String! 
    let title: String! 
    let year: Int! 
    let icon: UIImage! 
 
 
    init(id: String, title: String, year: Int, icon: UIImage) { 
        self.id = id 
        self.title = title 
        self.year = year 
        self.icon = icon 
    } 
 
    override init(){} 
 
    var bottlesArray = NSMutableArray() 
 
    // code inspired from http://stackoverflow.com/questions/24238868/swift-nscoding-not-working 
 
    required init(coder aDecoder: NSCoder) { 
        self.bottlesArray = aDecoder.decodeObjectForKey("bottleArray") as NSMutableArray 
    } 
 
    func encodeWithCoder(aCoder: NSCoder) { 
        aCoder.encodeObject(bottlesArray, forKey: "bottleArray") 
    } 
 
    func add(bottle: Bottle) { 
        self.bottlesArray.addObject(bottle) 
    } 
 
    func save() { 
        let data = NSKeyedArchiver.archivedDataWithRootObject(self) 
        NSUserDefaults.standardUserDefaults().setObject(data, forKey: "bottleList") 
    } 
 
    class func loadSaved() -> Bottle? { 
        if let data = NSUserDefaults.standardUserDefaults().objectForKey("bottleList") as? NSData { 
            return NSKeyedUnarchiver.unarchiveObjectWithData(data) as? Bottle 
        } 
        return nil 
    } 
 
    func saveBottle(bottle: Bottle) { 
        let bottleList = Bottle.loadSaved() 
        bottleList?.add(bottle) 
        bottleList?.save() 
        let bottleList2 = Bottle.loadSaved() 
        println(bottleList2?.bottlesArray.count) 
        println(bottleList2?.bottlesArray[0].title) 
    } 
} 

我节省了 3 瓶。最后两个 println 打印 3 和 nil 所以我的数组中确实有 3 个元素，但它们是 nil，我不明白为什么。我有另一个类保存 String 而不是 Bottle 并且没有像 init(id: String) 这样的 init 函数, title: String, year: Int, icon: UIImage) 一个，它工作正常。

以下是我如何保存我的瓶子:

var bottleLoaded = Bottle.loadSaved()! 
var bottleToSave = Bottle(id: bottleID, title: bottleName, year: bottleYear, icon: UIImage(data:bottleIconData)!) 
bottleLoaded.saveBottle(bottleToSave)     

就是这样。

为了“初始化”内存，我在之前的 ViewController 中也有以下代码

let bottleList = Bottle() 
bottleList.save()     

我也已经尝试添加 NSUserDefaults.standardUserDefaults().synchronize() 但它没有改变任何东西，我加载的对象仍然是零。

请您参考如下方法:

您需要在 NSCoding 方法中保存和检索 所有 Bottle 的属性:

required init(coder aDecoder: NSCoder) { 
    self.bottlesArray = aDecoder.decodeObjectForKey("bottleArray") as NSMutableArray 
    self.id = aDecoder.decodeObjectForKey("id") as String 
    //etc. same for title, year, and icon (use decodeIntegerForKey: for year) 
} 
 
func encodeWithCoder(aCoder: NSCoder) { 
    aCoder.encodeObject(bottlesArray, forKey: "bottleArray") 
    aCoder.encodeObject(self.id, forKey: "id") 
    //etc. same for title, year, and icon (use encodeInteger:forKey: for year) 
}