如何使用UserDefaults保存UIColor？

Swift 4.2或更高版本

请注意,这将仅将RGBA CGFloat值保存为属性列表中的数据.当使用NSKeyedUnarchiver(NSCoding)的标准方法时,这将使用32个字节(原始数据)而不是424个字节:

extension UserDefaults {
    func set(_ color: UIColor?, forKey defaultName: String) {
        var red: CGFloat = 0, green: CGFloat = 0, blue: CGFloat = 0, alpha: CGFloat = 0
        guard let color = color, color.getRed(&red, green: &green, blue: &blue, alpha: &alpha)
        else {
            removeObject(forKey: defaultName)
            return
        }
        let count = MemoryLayout.size
        set(Data(bytes: &red,   count: count) +
            Data(bytes: &green, count: count) +
            Data(bytes: &blue,  count: count) +
            Data(bytes: &alpha, count: count), forKey: defaultName)
    }
    func color(forKey defaultName: String) -> UIColor? {
        guard let data = data(forKey: defaultName) else {
           return nil
        }
        let size = MemoryLayout.size
        return UIColor(red:   data[size*0..



extension UserDefaults {
    var backgroundColor: UIColor? {
        get {
            return color(forKey: "backgroundColor")
        }
        set {
            set(newValue, forKey: "backgroundColor")
        }
    }
}




UserDefaults.standard.backgroundColor = .red
UserDefaults.standard.backgroundColor  // r 1.0 g 0.0 b 0.0 a 1.0