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我正在使用 Core Data 进行持久存储，我收到下面列出的错误。我查看了这条消息，我知道这与我使用可转换类和自定义类有关。尽管我进行了研究，但我不确定如何解决它。我尝试遵守 NSSecureCoding 协议失败了。我发布我的原始代码是因为我认为从头开始尝试解决问题可能比尝试修复我在 NSSecureCoding 上的糟糕尝试更容易。先感谢您！任何帮助深表感谢。

'NSKeyedUnarchiveFromData' 不应用于取消归档，并将在未来版本中删除

我的实体： 在此处输入图像描述

我的自定义类：

public class SelectedImages: NSObject, NSCoding {
    public var images: [SelectedImage] = []
    enum Key: String {
        case images = "images"
    }
    init(images: [SelectedImage]) {
        self.images = images
    }
    public func encode(with aCoder: NSCoder) {
        aCoder.encode(images, forKey: Key.images.rawValue)
    }
    public required convenience init?(coder aDecoder: NSCoder) {
        let mImages = aDecoder.decodeObject(forKey: Key.images.rawValue) as! [SelectedImage]
        self.init(images: mImages)
    }
}

public class SelectedImage: NSObject, NSCoding {
    public var location: Int = 0
    public var duration: Int = 10
    public var localIdentifier: String = ""
    
    enum Key: String {
        case location = "location"
        case duration = "duration"
        case localIdentifier = "localIdentifier"
    }
    init(location: Int, duration: Int, localIdentifier: String) {
        self.location = location
        self.duration = duration
        self.localIdentifier = localIdentifier
    }
    public override init() {
        super.init()
    }
    public func encode(with aCoder: NSCoder) {
        aCoder.encode(location, forKey: Key.location.rawValue)
        aCoder.encode(duration, forKey: Key.duration.rawValue)
        aCoder.encode(localIdentifier, forKey: Key.localIdentifier.rawValue)
    }
    public required convenience init?(coder aDecoder: NSCoder) {
        let mlocation = aDecoder.decodeInt32(forKey: Key.location.rawValue)
        let mduration = aDecoder.decodeInt32(forKey: Key.duration.rawValue)
        let mlocalIdentifier = aDecoder.decodeObject(forKey: Key.localIdentifier.rawValue) as! String
        self.init(location: Int(mlocation), duration:Int(mduration), localIdentifier:String(mlocalIdentifier))
    }
}

视图控制器：

guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else { return }
let managedContext = appDelegate.persistentContainer.viewContext
let userEntity = NSEntityDescription.entity(forEntityName: "EntityTest", in: managedContext)!
let selectedImages = NSManagedObject(entity: userEntity, insertInto: managedContext) as! EntityTest
let mImages = SelectedImages(images: selectionArrays)
selectedImages.setValue(mImages, forKeyPath: "image")
        
do {
    try managedContext.save()
    print("Images saved to core data")
} catch let error as NSError {
    print("Could not save. \(error), \(error.userInfo)")
}
    let newViewController = PickerTest6()
    self.navigationController?.pushViewController(newViewController, animated: true)
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1 回答 1

2

我没有运行此代码，但它应该可以工作。

  1. 对SelectedImage类进行更改。
public class SelectedImage: NSObject, NSSecureCoding { // Class must inherit from NSSecureCoding
    public static var supportsSecureCoding: Bool = true // It's the required property
    
    public var location: Int = 0
    public var duration: Int = 10
    public var localIdentifier: String = ""
    
    private enum CodingKeys: String {
        case location, duration, localIdentifier
    }
    
    public override init() {
        super.init()
    }
    
    init(location: Int, duration: Int, localIdentifier: String) {
        self.location = location
        self.duration = duration
        self.localIdentifier = localIdentifier
    }
    
    public required init?(coder: NSCoder) {
        self.location = coder.decodeInteger(forKey: CodingKeys.location.rawValue)
        self.duration = coder.decodeInteger(forKey: CodingKeys.duration.rawValue)
        
        // Now instead of decodeObject(forKey:) you should use decodeObject(of: forKey:).
        self.localIdentifier = coder.decodeObject(of: NSString.self, forKey: CodingKeys.localIdentifier.rawValue) as String? ?? ""
    }
    
    public func encode(with coder: NSCoder) {
        coder.encode(location, forKey: CodingKeys.location.rawValue)
        coder.encode(duration, forKey: CodingKeys.duration.rawValue)
        coder.encode(localIdentifier, forKey: CodingKeys.localIdentifier.rawValue)
    }
}
  1. 创建SelectedImageTransformer类。
@objc(SelectedImageTransformer)
final class SelectedImageTransformer: NSSecureUnarchiveFromDataTransformer {
    static let name = NSValueTransformerName(rawValue: String(describing: SelectedImageTransformer.self))
    
    override class var allowedTopLevelClasses: [AnyClass] {
        return super.allowedTopLevelClasses + [SelectedImage.self]
    }

    public class func register() {
        let transformer = SelectedImageTransformer()
        ValueTransformer.setValueTransformer(transformer, forName: name)
    }
}
  1. 按如下方式编辑 CoreData 模型。

在此处输入图像描述

  1. 在初始化持久容器之前调用AppDelegate中的 register 方法（如果您使用 UIKit）。
// MARK: - Core Data stack
lazy var persistentContainer: NSPersistentContainer = {
    // Register the transformer
    SelectedImageTransformer.register()
    
    let container = NSPersistentContainer(name: "AppName")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

有关更多详细信息，您可以阅读本文或本文。

于 2021-03-09T09:45:42.660 回答