我希望能够将Custom-struct
保存到UserDefaults
,但为此我需要将其保存为Codable
。我尝试过这样的操作:
struct Wishlist: Codable {
var name: String
var image: UIImage
var wishData: [Wish]
var color: UIColor
var textColor: UIColor
var index: Int
}
但是这给了我这个error
:
类型“愿望清单”不符合协议“可解码”
这里是我的Class Wish
,也许是问题所在:
class Wish: NSObject {
public var wishName : String?
public var checkedStatus : Bool?
public var wishLink : String?
public var wishPrice : String?
public var wishNote : String?
public var wishImage : UIImage?
init(withWishName name: String, link: String, price: String, note: String, image: UIImage, checked: Bool) {
super.init()
wishName = name
checkedStatus = checked
wishLink = link
wishPrice = price
wishNote = note
wishImage = image
}
}
我在这里做错了什么?
您将需要使Wish
采用Codable
。
但是因为UIImage
和UIColor
不是Codable
,所以您必须按照Encoding and Decoding Custom Types中的说明手动实现它们:
struct Wishlist: Codable {
var name: String
var image: UIImage
var wishes: [Wish]
var color: UIColor
var textColor: UIColor
var index: Int
enum CodingKeys: String, CodingKey {
case name, image, wishData, color, textColor, index
}
init(name: String, image: UIImage, wishes: [Wish], color: UIColor, textColor: UIColor, index: Int) {
self.name = name
self.image = image
self.wishes = wishes
self.color = color
self.textColor = textColor
self.index = index
}
init(from decoder: Decoder) throws {
let values = try decoder.container(keyedBy: CodingKeys.self)
name = try values.decode(String.self, forKey: .name)
wishes = try values.decode([Wish].self, forKey: .wishData)
color = try values.decode(Color.self, forKey: .color).uiColor
textColor = try values.decode(Color.self, forKey: .textColor).uiColor
index = try values.decode(Int.self, forKey: .index)
let data = try values.decode(Data.self, forKey: .image)
guard let image = UIImage(data: data) else {
throw DecodingError.dataCorruptedError(forKey: .image, in: values, debugDescription: "Invalid image data")
}
self.image = image
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(name, forKey: .name)
try container.encode(wishes, forKey: .wishData)
try container.encode(Color(uiColor: color), forKey: .color)
try container.encode(Color(uiColor: textColor), forKey: .textColor)
try container.encode(index, forKey: .index)
try container.encode(image.pngData(), forKey: .image)
}
}
struct Wish: Codable {
public var name: String
public var checkedStatus: Bool
public var link: String
public var price: String
public var note: String
public var image: UIImage
init(name: String, link: String, price: String, note: String, image: UIImage, checkedStatus: Bool) {
self.name = name
self.checkedStatus = checkedStatus
self.link = link
self.price = price
self.note = note
self.image = image
}
enum CodingKeys: String, CodingKey {
case name, checkedStatus, link, price, note, image
}
init(from decoder: Decoder) throws {
let values = try decoder.container(keyedBy: CodingKeys.self)
name = try values.decode(String.self, forKey: .name)
checkedStatus = try values.decode(Bool.self, forKey: .checkedStatus)
link = try values.decode(String.self, forKey: .link)
price = try values.decode(String.self, forKey: .price)
note = try values.decode(String.self, forKey: .note)
let data = try values.decode(Data.self, forKey: .image)
guard let image = UIImage(data: data) else {
throw DecodingError.dataCorruptedError(forKey: .image, in: values, debugDescription: "Invalid image data")
}
self.image = image
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(name, forKey: .name)
try container.encode(checkedStatus, forKey: .checkedStatus)
try container.encode(link, forKey: .link)
try container.encode(price, forKey: .price)
try container.encode(note, forKey: .note)
try container.encode(image.pngData(), forKey: .image)
}
}
我将其用作编码UIColor
对象的便捷方法:
struct Color: Codable {
let red: CGFloat
let green: CGFloat
let blue: CGFloat
let alpha: CGFloat
init(red: CGFloat, green: CGFloat, blue: CGFloat, alpha: CGFloat) {
self.red = red
self.green = green
self.blue = blue
self.alpha = alpha
}
init(uiColor: UIColor) {
var red: CGFloat = 0
var green: CGFloat = 0
var blue: CGFloat = 0
var alpha: CGFloat = 0
uiColor.getRed(&red, green: &green, blue: &blue, alpha: &alpha)
self.red = red
self.green = green
self.blue = blue
self.alpha = alpha
}
var uiColor: UIColor { UIColor(red: red, green: green, blue: blue, alpha: alpha) }
}
注意,我做了几个不相关的更改:
我都做了这两个struct
。除非必要,否则我不会介绍引用类型(更少的NSObject
子类)。
我简化了一些属性名称。例如。在Wish
中,我们通常不会在属性名称中使用wish
前缀。我也不会在属性名称中使用“数据”,除非它实际上是Data
。
我更新了init
方法以使用标准命名约定。
也您的班级希望必须实现可编码协议
UIImage
不符合Codable
。您可以先将其转换为Base64,然后将that存储在UserDefaults
中。