Question

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打印我3和nil所以我的数组确实有3个元素，但它们是零，我不明白为什么。我有另一个课程可以保存String而不是Bottle而且没有像init这样的init(id: String, title: String, year: Int, icon: UIImage)函数，它可以正常工作。

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)

那就是它。

我在之前的ViewController中也有以下代码，以便＆＃34;初始化＆＃34;记忆

let bottleList = Bottle()
bottleList.save()

我也尝试添加NSUserDefaults.standardUserDefaults().synchronize()，但它没有改变任何内容，我加载的对象仍为零。

Answer 1

您需要在Bottle方法中保存并检索所有 NSCoding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)
}

使用NSKeyedArchiver保存并加载的对象为零

1 个答案: