如何在 NSUserDefaults 中使用（多种类型）保存数组

Question

这很简单，但似乎找不到正确的信息来解决在用户默认值中保存这样的数组的问题。

它说它不是 NSUser Defaults Excepts 的属性。

代码：

    var notificationList: [(type: String,imageName: String, text: String, date: String, seen: Bool)] = [(type: "Default",imageName: "ClearPartioned", text: "", date: "", seen: true)]


    if (UserDefaults.standard.object(forKey: "notificationList")) == nil { // first time launching

        print("making notification list")

        UserDefaults.standard.set(notificationList, forKey: "notificationList")
        UserDefaults.standard.synchronize()

        print("\(notificationList)")

    } else {

        print("getting saved array")

        notificationList = (UserDefaults.standard.object(forKey: "notificationList") as! [(type: String, imageName: String, text: String, date: String, seen: Bool)])

        print("\(notificationList)")
    }

更新：

这更接近，但给出了在这个问题 here 中发现的错误。这些是我能够找到的最隐秘的答案，它们要么已经过时，要么会导致系统崩溃。

代码：

    if (UserDefaults.standard.object(forKey: "notificationList")) == nil { // first time launching

        print("making notification list")

        let encodedData = NSKeyedArchiver.archivedData(withRootObject: notificationList)
        UserDefaults.standard.set(encodedData, forKey: "notificationList")
        UserDefaults.standard.synchronize()

    } else {

        print("getting saved array")

        notificationList = (UserDefaults.standard.object(forKey: "notificationList") as! [(type: String, imageName: String, text: String, date: String, seen: Bool)])

        print("\(notificationList)")
    }

更新 2： 这是来自 Dhiru

的最佳答案实现

代码：

  if (UserDefaults.standard.object(forKey: "notificationList")) == nil { // first time launching
        print("making notification list")

        let notificationData = NSKeyedArchiver.archivedData(withRootObject: notificationList)
        UserDefaults.standard.set(notificationData, forKey: "notificationList")
        UserDefaults.standard.synchronize()

    } else {

        print("getting saved array")

        let decodedData  = UserDefaults.standard.object(forKey: "notificationList") as! Data
        let notificationList = NSKeyedUnarchiver.unarchiveObject(with: decodedData) as AnyObject

        print("\(notificationList)")
    }

它给我一个导致系统崩溃的错误

   *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[_SwiftValue encodeWithCoder:]: unrecognized selector sent to instance 0x1c011f380'
   libc++abi.dylib: terminating with uncaught exception of type NSException

我确定这段代码会修复它，但由于我不知道如何使用这段代码，所以执行起来很糟糕，下面有多个错误。

代码：

   func (coder aDecoder: NSCoder) {
        if let notificationList = aDecoder.decodeObjectForKey("notificationList") {
            self.notificationList = notificationList
        }
    }

    func encodeWithCoder(aCoder: NSCoder) {
        if let notificationList = notificationList {
            aCoder.encodeObject(notificationList, forKey: "notificationList")
        }
    }

Answer 1

您必须以 Data 的形式存储您的对象转换成数据使用 NSKeyedArchiver.archivedData(withRootObject:)

转换回对象使用 NSKeyedUnarchiver.unarchiveObject(with:)

为 UserDefaults 保存数据

let notificationData = NSKeyedArchiver.archivedData(withRootObject: notificationList)
UserDefaults.standard.set(notificationData, forKey: "notificationList")

从用户 UserDefaults 中检索数据

let decodedData  = UserDefaults.standard.object(forKey: "notificationList") as! Data
let notificationList = NSKeyedUnarchiver.unarchiveObject(with: decodedData) as! AnyObject

Answer 2

这就是我在 Swift 4.

中实际保存在应用程序中创建的自定义对象的方式

首先，我们创建了 3 个协议，用于将自定义对象保存在 UserDefaults 中。背后的逻辑是将 Custom Object 转换为规范化的 Dictionary/Array 形式。

This can be applied to any kind of Object which you have created.

这 3 个协议是：

Decoder（用于将字典解码为自定义对象）
Encoder（用于将自定义对象编码成字典）
UserDefaultsProtocol（用于保存、删除、更新和检索来自 UserDefault 的自定义对象）

解码协议

protocol Decoder {
    associatedtype T
    static func decode(dictionary: [String: Any]) -> T
}

编码器协议

protocol Encoder {
    func encode() -> [String: Any]
}

用户默认协议

protocol UserDefaultsDelegate: class {
    associatedtype T
    func saveToUserDefaults()
    static func removeFromUserDefaults()
    static func retrieveFromUserDefaults() -> T?
}

根据您的问题，NotificationList 对象看起来像这样

class NotificationList {
    var type: String = ""
    var imageName: String = ""
    var text: String = ""
    var date: String = ""
    var seen: Bool = false
}

现在，您需要向 NotificationList 确认所有提到的 3 个协议。（Swift 最佳实践：扩展和协议的使用）

class NotificationList {
    private struct Constants {
        static let RootKey = "notification_list"
        static let TypeKey = "type"
        static let ImageNameKey = "image_name"
        static let TextKey = "text"
        static let DateKey = "date"
        static let SeenKey = "seen"
    }

    var type: String = ""
    var imageName: String = ""
    var text: String = ""
    var date: String = ""
    var seen: Bool = false

    typealias T = NotificationList
}

extension NotificationList: Encoder {
    func encode() -> [String : Any] {
        return [
            Constants.TypeKey: type,
            Constants.ImageNameKey: imageName,
            Constants.TextKey: text,
            Constants.DateKey: date,
            Constants.SeenKey: seen
        ]
    }
}

extension NotificationList: Decoder {
    static func decode(dictionary: [String: Any]) -> NotificationList {
        let type = dictionary[Constants.TypeKey] as! String
        let imageName = dictionary[Constants.ImageNameKey] as! String
        let text = dictionary[Constants.TextKey] as! String
        let date = dictionary[Constants.DateKey] as! String
        let seen = dictionary[Constants.SeenKey] as! Bool

        let notificationList = NotificationList()
        notificationList.type = type
        notificationList.imageName = imageName
        notificationList.text = text
        notificationList.date = date
        notificationList.seen = seen
        return notificationList
    }
}

extension NotificationList: UserDefaultsDelegate {

    func saveToUserDefaults() {
        UserDefaults.standard.setValue(encode(), forKey: Constants.RootKey)
    }

    static func retrieveFromUserDefaults() -> NotificationList? {
        guard let encodedNotificationList = UserDefaults.standard.dictionary(forKey: Constants.RootKey) else {
            return nil
        }
        return NotificationList.decode(dictionary: encodedNotificationList)
    }

    static func removeFromUserDefaults() {
        UserDefaults.standard.removeObject(forKey: Constants.RootKey)
    }
}

如何将NotificationList保存到UserDefaults？

var notificationList = NotificationList()
notificationList.type = "Default"
notificationList.imageName = "ClearPartioned"
notificationList.text = ""
notificationList.date = ""
notificationList.seen = true

保存到用户默认值

notificationList.saveToUserDefaults()

从 UserDefaults 中检索

if let notificationList = NotificationList.retrieveFromUserDefaults() {
      // You will get the instance of notification list saved in UserDefaults
}

如何保存通知列表数组？

假设 notificationLists 包含 notificationList 对象数组。

var notificationListsArray = [[String: Any]]()

notificationLists.forEach {
     notificationListsArray.append([=18=].encode())
}

将该字典数组保存到 UserDefaults

UserDefaults.standard.setValue(notificationListsArray, forValue: "notificationLists")

如何在 NSUserDefaults 中使用（多种类型）保存数组

How to save a Array with (Multiple Types) in NSUserDefaults

ios

swift

nsuserdefaults