Xcode-project 不使用 NSKeyedArchiver 存档，但 Playground 可以

Question

我在使用 NSCoding 和 NSObject 归档时遇到了一些问题。这在 Playground 中运行良好。但似乎在 Xcode 中不起作用。有人可以帮我解决这个问题吗？

每次我打电话：

NSKeyedArchiver.archiveRootObject(person, toFile: "person")

它在 Playground 中有效并返回 true，但在项目中返回 false。我不使用模拟器。

我一直在寻找相同类型的问题，但是我似乎找不到与此相关的任何内容。

class Person: NSObject, NSCoding {

private var _name: String = "name"
private var _birthdate: Date = Date()
private var _income: Int = -1
private var _wealth: Int = -1

var name: String {
    get { return _name }
    set (newName) { _name = newName }
}
var birthdate: Date {
    get { return _birthdate }
    set (newBirthdate) { _birthdate = newBirthdate }
}
var income: Int {
    get { return _income }
    set (newIncome) { _income = newIncome }
}
var wealth: Int {
    get { return _wealth }
    set (newWealth) { _wealth = newWealth }
}

override init(){}

required convenience init(coder unarchiver: NSCoder) {

    self.init()

    if let name = unarchiver.decodeObject(forKey: "name") as? String {
        self.name = name
    }
    if let birthdate = unarchiver.decodeObject(forKey: "birthdate") as? Date {
        self.birthdate = birthdate
    }
    let income = unarchiver.decodeInteger(forKey: "income")
    self.income = income

    let wealth = unarchiver.decodeInteger(forKey: "wealth")
    self.wealth = wealth

}

func encode(with archiver: NSCoder) {

    archiver.encode(name, forKey: "name")
    archiver.encode(birthdate, forKey: "birthdate")
    archiver.encode(income, forKey: "income")
    archiver.encode(wealth, forKey: "wealth")
} 
}

然后我创建一个人并将其归档。

let person = Person()
NSKeyedArchiver.archiveRootObject(person, toFile: "person")

Answer 1

你需要在你的 Person 类中对你的 init 做一个小的编辑。删除convenience关键字并将self.init()替换为super.init()：

class Person: NSObject, NSCoding {

    private var _name: String = "name"
    private var _birthdate: Date = Date()
    private var _income: Int = -1
    private var _wealth: Int = -1

    var name: String {
        get { return _name }
        set (newName) { _name = newName }
    }
    var birthdate: Date {
        get { return _birthdate }
        set (newBirthdate) { _birthdate = newBirthdate }
    }
    var income: Int {
        get { return _income }
        set (newIncome) { _income = newIncome }
    }
    var wealth: Int {
        get { return _wealth }
        set (newWealth) { _wealth = newWealth }
    }

    override init() {}

    required init(coder unarchiver: NSCoder) {

        super.init()

        if let name = unarchiver.decodeObject(forKey: "name") as? String {
            self.name = name
        }
        if let birthdate = unarchiver.decodeObject(forKey: "birthdate") as? Date {
            self.birthdate = birthdate
        }
        let income = unarchiver.decodeInteger(forKey: "income")
        self.income = income

        let wealth = unarchiver.decodeInteger(forKey: "wealth")
        self.wealth = wealth

    }

    func encode(with archiver: NSCoder) {

        archiver.encode(name, forKey: "name")
        archiver.encode(birthdate, forKey: "birthdate")
        archiver.encode(income, forKey: "income")
        archiver.encode(wealth, forKey: "wealth")
    } 
}

一旦你这样做了，你可以在任何你想要的地方调用存档器（我在 viewDidLoad 中这样做只是为了测试并且它有效）给它一个这样的路径：

let person = Person()
let path = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("person").path
let personWasUploaded: Bool = NSKeyedArchiver.archiveRootObject(person, toFile:path)
print(path)
print("person uploaded: \(personWasUploaded)")