使 CAShapeLayer 和 CGPath 符合 Codable 或 NSCoding

问题描述

我正在尝试使用 Codable 协议在 .json 文件中保存和获取有关 CAShapeLayers 的信息，但出现错误：

public class Node: Codable {


public var name: String = ""

public var path: CGPath?
    
public var baseLayer: CAShapeLayer?


public required init(from decoder: Decoder) throws {
    let container = try? decoder.container(keyedBy: NodeCodingKeys.self)
           
    let _name = try container?.decodeIfPresent(String.self,forKey: NodeCodingKeys.name)
    
    let _baseLayer = try container?.decodeIfPresent(CAShapeLayer.self,forKey: NodeCodingKeys.baseLayer)
    name = _name ?? ""
}

public func encode(to encoder: Encoder) throws {
    var container = encoder.container(keyedBy: NodeCodingKeys.self)
    try container.encode(name,forKey: NodeCodingKeys.name)
}
}

public enum NodeCodingKeys: CodingKey {
    
    case path
    case name
    case baseLayer
    
}

CGPath 也是如此。有什么方法可以将它们保存到设备/从设备接收它们？

解决方法

我找不到让 CAShapeLayer 符合 Codable 的方法，所以我为我的数据对象创建了类：

public class ImageNode: NSObject,NSCoding,NSSecureCoding {
    public static var supportsSecureCoding = true
    var name: NSString
    var baseLayer: CAShapeLayer
    
    init(name: NSString,baseLayer: CAShapeLayer
         ) {
            self.name = name
            self.baseLayer = baseLayer
        }
    
    public func encode(with coder: NSCoder) {
        
        coder.encode(name,forKey: "name")
        coder.encode(baseLayer,forKey: "baseLayer")        
    }
    
    public required convenience init?(coder: NSCoder) {
        guard let name = coder.decodeObject(forKey: "name") as? NSString
            else { return nil }
        guard let baseLayer = coder.decodeObject(forKey: "baseLayer") as? CAShapeLayer
            else { return nil }
             
        print("decode node")
            self.init(
                name: name,baseLayer: baseLayer
            )
    } }

与 NSKeyedArchiver 和 NSKeyedUnarchiver 配合使用，可以将数据保存到文件并检索它。也许这个解决方案会对某人有所帮助。