Question

我正在尝试在userDefaults中存储一个数组，但是当我运行我的应用程序时出现此错误：

＆＃39;尝试插入非属性列表对象（＆＃34; Morning_Star_2.Event（标题：可选（\＆＃34;测试标题\＆＃34;），位置：可选（\＆＃34;测试位置\＆＃34;））＆＃34; ）用于关键测试＆＃39;

这是我的代码：

import UIKit

class ViewController: UIViewController {


    @IBOutlet weak var txtTitle: UITextField!

    @IBOutlet weak var txtLocation: UITextField!

    @IBOutlet weak var txtDate: UITextField!

    @IBOutlet weak var txtTime: UITextField!

    var eventsArray = [Event]()


       @IBAction func btnSave() {

        let savedEvents = UserDefaults.standard.object(forKey: "test")

        let event = Event(eventTitle: txtTitle.text!, eventLocation: txtLocation.text!)

        if let tempEvents = savedEvents {
            eventsArray = tempEvents as! [Event]
            eventsArray.append(event)

        }
        else {
            let event = Event(eventTitle: txtTitle.text!, eventLocation: txtLocation.text!)
            eventsArray.append(event)
        }

        UserDefaults.standard.set(eventsArray, forKey: "test")


        //print(eventsArray)

        }

}

Answer 1

要在UserDefaults中存储自定义对象，您的对象必须

继承自NSObject
符合NSCoding协议

类实现的示例可能如下所示：

class Event: NSObject, NSCoding {

    private var eventTitle: String!
    private var eventLocation: String!

    init(eventTitle: String, eventLocation: String) {
        self.eventTitle = eventTitle
        self.eventLocation = eventLocation
    }

    override init() {

    }

    required convenience init?(coder aDecoder: NSCoder) {
        self.init()
        eventTitle = aDecoder.decodeObject(forKey: "eventTitle") as? String
        eventLocation = aDecoder.decodeObject(forKey: "eventLocation") as? String
    }

    func encode(with aCoder: NSCoder) {
        aCoder.encode(eventTitle, forKey: "eventTitle")
        aCoder.encode(eventLocation, forKey: "eventLocation")
    }

}

现在，您只能在UserDefaults中存储某些对象。幸运的是，类型数据可以存储在UserDefaults中。然后，您需要将数组转换为Data，然后存储它。

let data = NSKeyedArchiver.archivedData(withRootObject: eventsArray) 
// This calls the encode function of your Event class

UserDefaults.standard.set(data, forKey: "test")
/* This saves the object to a buffer, but you will need to call synchronize, 
before it is actually saved to UserDefaults */

UserDefaults.standard.synchronize()

当您检索数据时，它会以“任何？”的形式返回，它必须被转换为您的对象：

if let data = UserDefaults.standard.object(forKey: "test") as? Data {
    if let storedData = NSKeyedUnarchiver.unarchiveObject(with: data) as? [Event] {
            // In here you can access your array
    }
}

如何在NSUserDefaults中存储数组？斯威夫特3

1 个答案: