在阵列上使用NSUserDefaults

Question

我正在尝试使用NSUserDefaults将数组保存到我的应用程序的核心数据中。我认为使用NSUserDefaults会很好，但是问题是，无论我将创建默认代码的代码放在哪里，都会引发SIGABRT错误。

这是创建默认值的代码：

let levelArrayDefault = NSUserDefaults.standardUserDefaults()
    levelArrayDefault.setValue(levelsArray, forKey: "levelsArray")
    levelArrayDefault.synchronize()

levelsArray是List对象的数组：

    class List: NSObject, NSCoding {
    // MARK: Properties
    var name: String
    var AnswersArray = [Answer]()


    init?(name: String) {
        // Initialize stored properties.
        self.name = name

        if name.isEmpty {
            return nil
        }

    }

    required init(coder decoder: NSCoder){
        self.AnswersArray = (decoder.decodeObjectForKey("AA") as? [Answer])!
        self.name = (decoder.decodeObjectForKey("name") as? String)!
    }
    func encodeWithCoder(coder: NSCoder) {
        if let AnswersArray = AnswersArray { coder.encodeObject(AnswersArray, forKey: "AA") }
        if let name = name { coder.encodeObject(name, forKey: "name") }
    }


}
class Answer: NSObject, NSCoding {
    var EnglishAnswer: String = ""
    var ChineseAnswer: String = ""
    init(newEng: String, newChi: String){
        self.EnglishAnswer = newEng
        self.ChineseAnswer = newChi
    }
    required init(coder decoder: NSCoder){
        self.EnglishAnswer = (decoder.decodeObjectForKey("EnglishAnswer") as? String)!
        self.ChineseAnswer = (decoder.decodeObjectForKey("ChineseAnswer") as? String)!
    }
    func encodeWithCoder(coder: NSCoder) {
        if let EnglishAnswer = EnglishAnswer { coder.encodeObject(EnglishAnswer, forKey: "EnglishAnswer") }
        if let ChineseAnswer = ChineseAnswer { coder.encodeObject(ChineseAnswer, forKey: "ChineseAnswer") }
    }

}

如何阻止SIGABRT弹出并存储阵列。帮助将不胜感激。

Answer 1

您需要先使用NSKeyedArchiver将其转换为NSData，然后再将其存储到NSUserDefaults中，如下所示：

更新：Xcode 8.2.1•Swift 3.0.2

import UIKit
class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        let list = List(name: "Student")
        list.answers = [Answer(english: "english answer", chinese: "中文回答")]
        let data = NSKeyedArchiver.archivedData(withRootObject: [list])
        UserDefaults.standard.set(data, forKey: "listData")
        guard
            let loadedData = UserDefaults.standard.data(forKey: "listData"),
            let loadedArray = NSKeyedUnarchiver.unarchiveObject(with: loadedData) as? [List]
            else { return }
        print(loadedData.count)
        print(loadedArray.first ?? "none")
        print(loadedArray.first?.name ?? "no name")
        print(loadedArray.first?.answers.first?.english ?? "no english")
        print(loadedArray.first?.answers.first?.chinese ?? "no chinese")
    }
}

class Answer: NSObject, NSCoding {
    let english: String
    let chinese: String
    init(english: String, chinese: String) {
        self.english = english
        self.chinese = chinese
    }
    required init(coder decoder: NSCoder) {
        self.english = decoder.decodeString(forKey: "english")
        self.chinese = decoder.decodeString(forKey: "chinese")
    }
    func encode(with coder: NSCoder) {
        coder.encode(english, forKey: "english")
        coder.encode(chinese, forKey: "chinese")
    }
}

class List: NSObject, NSCoding {
    let name: String
    fileprivate var data = Data()
    var answers: [Answer] {
        get {
            return NSKeyedUnarchiver.unarchiveObject(with: data) as? [Answer] ?? []
        }
        set {
            data = NSKeyedArchiver.archivedData(withRootObject: newValue)
        }
    }
    init(name: String) {
        self.name = name
    }
    required init(coder decoder: NSCoder) {
        self.data = decoder.decodeData(forKey: "answersData")
        self.name = decoder.decodeString(forKey: "name")
    }
    func encode(with coder: NSCoder) {
        coder.encode(data, forKey: "answersData")
        coder.encode(name, forKey: "name")
    }
}

extension NSCoder {
    func decodeString(forKey key: String) -> String {
        return decodeObject(forKey: key) as? String ?? ""
    }
    func decodeData(forKey key: String) -> Data {
        return decodeObject(forKey: key) as? Data ?? Data()
    }
}