尝试在 Swift 3 中保存自定义对象时尝试插入非属性列表对象

我有一个简单的对象，符合NSCoding协议。

import Foundation

class JobCategory: NSObject, NSCoding {
    var id: Int
    var name: String
    var URLString: String

    init(id: Int, name: String, URLString: String) {
        self.id = id
        self.name = name
        self.URLString = URLString
    }

    // MARK: - NSCoding
    required init(coder aDecoder: NSCoder) {
        id = aDecoder.decodeObject(forKey: "id") as? Int ?? aDecoder.decodeInteger(forKey: "id")
        name = aDecoder.decodeObject(forKey: "name") as! String
        URLString = aDecoder.decodeObject(forKey: "URLString") as! String
    }

    func encode(with aCoder: NSCoder) {
        aCoder.encode(id, forKey: "id")
        aCoder.encode(name, forKey: "name")
        aCoder.encode(URLString, forKey: "URLString")
    }
}

我正在尝试将其实例保存在UserDefaults但它一直失败并出现以下错误。

由于未捕获的异常“NSInvalidArgumentException”而终止应用程序，原因：“尝试插入关键 jobCategory 的非属性列表对象”

这是我保存的代码UserDefaults.

enum UserDefaultsKeys: String {
    case jobCategory
}

class ViewController: UIViewController {

    @IBAction func didTapSaveButton(_ sender: UIButton) {
        let category = JobCategory(id: 1, name: "Test Category", URLString: "http://www.example-job.com")

        let userDefaults = UserDefaults.standard
        userDefaults.set(category, forKey: UserDefaultsKeys.jobCategory.rawValue)
        userDefaults.synchronize()
    }
}

我将枚举值替换为普通字符串，但仍然出现相同的错误。知道是什么原因造成的吗？

你需要创建Data实例来自你的JobCategory模型使用JSONEncoder并存储它Data实例在UserDefaults并稍后使用解码JSONDecoder.

struct JobCategory: Codable {
    let id: Int
    let name: String
}

// To store in UserDefaults
if let encoded = try? JSONEncoder().encode(category) {
    UserDefaults.standard.set(encoded, forKey: UserDefaultsKeys.jobCategory.rawValue)
}

// Retrieve from UserDefaults
if let data = UserDefaults.standard.object(forKey: UserDefaultsKeys.jobCategory.rawValue) as? Data, 
   let category = try? JSONDecoder().decode(JobCategory.self, from: data) {
     print(category.name)
}

旧答案

你需要创建Data实例来自你的JobCategory实例使用archivedData(withRootObject:)并存储它Data实例在UserDefaults然后使用取消存档unarchiveTopLevelObjectWithData(_:)，所以尝试这样。

用于将数据存储在UserDefaults

let category = JobCategory(id: 1, name: "Test Category", URLString: "http://www.example-job.com")
let encodedData = NSKeyedArchiver.archivedData(withRootObject: category, requiringSecureCoding: false)
let userDefaults = UserDefaults.standard
userDefaults.set(encodedData, forKey: UserDefaultsKeys.jobCategory.rawValue)

用于检索数据UserDefaults

let decoded  = UserDefaults.standard.object(forKey: UserDefaultsKeys.jobCategory.rawValue) as! Data
let decodedTeams = NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(decoded) as! JobCategory
print(decodedTeams.name)