协议扩展中解码器的初始化给出错误“调用'self.init'或分配给'self'之前使用的'self'”

问题描述

我想解码协议的扩展：

protocol SettingsContentProtocol: Codable {
    var audioDelegate:AudioDelegate? { get set }
    var isPlaying: Bool { get set }
    var meditationTimes: [MeditationItem: TimeInterval] {get set}
    var intermediate: Int {get set}
    var contentsDuration: Float {get set}
    var durata:TimeInterval {get set}
    var parzialeDurata:TimeInterval {get set}
    var date: Date {get set}
    var hour: Int {get}
    var followDuration: TimeInterval {get set}

    func selectPeriod(item:MeditationItem)
    mutating func sliderMoved(item: MeditationItem,sliderPosition: Float)
    func calculateContentsDuration()->Float
    func tooShortTimeForContents(completion:@escaping ((Bool)->Void))
    func cleanQueue(items:[MPMediaItem])
    func selectRow(indexPath: IndexPath)
    func tableEdit(indexPath: IndexPath)
    func rowAt(indexPath: IndexPath,tableView: UITableView)->UITableViewCell
    mutating func adjustProgress(progress: TimeInterval)
    mutating func prepareMeditation()
    func meditationDetails()->Meditation
    func meditationMessage(final: Bool)->String
    func meditationTime()->String
}

具有：

init(from decoder: Decoder) throws {
    let container = try decoder.container(keyedBy: CodingKeys.self)
    isPlaying = try container.decode(Bool.self,forKey: .isPlaying)
    meditationTimes = try container.decode([MeditationItem: TimeInterval].self,forKey: .meditationTimes)
    intermediate=try container.decode(Int.self,forKey: .intermediate)
    contentsDuration=try container.decode(Float.self,forKey: .contentsDuration)
    durata=try container.decode(TimeInterval.self,forKey: .durata)
    parzialeDurata=try container.decode(TimeInterval.self,forKey: .parzialeDurata)
    date=try container.decode(Date.self,forKey: .date)
    followDuration=try container.decode(TimeInterval.self,forKey: .followDuration)
}

但是，当我编译时，每行都会出现错误：

“”'self'在调用'self.init'或分配给'self'之前使用”

我发现的所有示例似乎都与我的代码一致，而可能是什么错误呢？

解决方法

这个问题是通过在每个当然采用struct的协议中设置标准的init（）来解决的，我从init（from :)调用它的方法如下：

func encode(to encoder: Encoder) throws{
    var container = encoder.container(keyedBy: CodingKeys.self)
    try container.encode(isPlaying,forKey: .isPlaying)
    try container.encode(meditationTimes,forKey: .meditationTimes)
    try container.encode(intermediate,forKey: .intermediate)
    try container.encode(durata,forKey: .durata)
    try container.encode(parzialeDurata,forKey: .parzialeDurata)
    try container.encode(date,forKey: .date)
    try container.encode(followDuration,forKey: .followDuration)
}


init(from decoder: Decoder) throws {
    self.init()
    let container = try decoder.container(keyedBy: CodingKeys.self)
    isPlaying = try container.decode(Bool.self,forKey: .isPlaying)
    meditationTimes = try container.decode([MeditationItem: TimeInterval].self,forKey: .meditationTimes)
    intermediate=try container.decode(Int.self,forKey: .intermediate)
    durata=try container.decode(TimeInterval.self,forKey: .durata)
    parzialeDurata=try container.decode(TimeInterval.self,forKey: .parzialeDurata)
    date=try container.decode(Date.self,forKey: .date)
    followDuration=try container.decode(TimeInterval.self,forKey: .followDuration)
}