archivedData(withRootObject:)' 在 iOS 12.0 中已弃用 - Swift 5 和 Flutter

Question

我有一个用 Swift 4 编写的项目（iOS 部分）。我将其更新到 5，但现在我收到了此警告。我尝试按照建议修复它，但每次都会遇到不同的错误。你能帮我吗？

代码

func saveData(data: BloodData) {
    if let defaults = getUserDefaults() {
      BloodData.registerClassName()
      let encodedData: Data = NSKeyedArchiver.archivedData(withRootObject: data)
      defaults.set(encodedData, forKey: dataKey)
      defaults.synchronize()
    }
  }

警告

archivedData(withRootObject:)' was deprecated in iOS 12.0: Use +archivedDataWithRootObject:requiringSecureCoding:error: instead

代码

 func getData() -> BloodData? {
    BloodData.registerClassName()
    if let defaults = getUserDefaults(), let data = defaults.data(forKey: dataKey), let decodedData = NSKeyedUnarchiver.unarchiveObject(with: data) as? BloodData {
      return computeData(data: decodedData)
    }
    return nil
  }

警告

'unarchiveObject(with:)' was deprecated in iOS 12.0: Use +unarchivedObjectOfClass:fromData:error: instead

这是一个computeData函数：

private func computeData(data: BloodData) -> BloodData? {
    let today = Date()
    
    let calendar = Calendar.current

    let date1 = calendar.date(bySettingHour: 12, minute: 00, second: 00, of: calendar.startOfDay(for: data.readingDate))!
    
    let date2 = calendar.date(bySettingHour: 12, minute: 00, second: 00, of: calendar.startOfDay(for: today))!

    let components = calendar.dateComponents([.day], from: date1, to: date2)
    let dayDiff = components.day ?? 0
    
    let newBloodData = BloodData(
      whiteCells: data.whiteCells - dayDiff,
      fullBlood: data.fullBlood - dayDiff,
      platelet: data.platelet - dayDiff,
      redCells1: data.redCells1 - dayDiff,
      redCells2: data.redCells2 - dayDiff,
      bloodPlasma: data.bloodPlasma - dayDiff,
      readingDate: date2
    )
    
    return newBloodData
  }

Answer 1

大多数时候用 Swift 编码时，错误并没有多大帮助。第一个是非常不言自明的，除了建议的方法可能会抛出错误。您可以删除 throw 关键字并使用 try? 忽略错误。如果您愿意，但最好捕获并处理错误：

func save(blood: BloodData, forKey defaultName: String = "BloodDataKey") {  // or forKey defaultName: String = dataKey
    guard let data = try? NSKeyedArchiver.archivedData(withRootObject: blood, requiringSecureCoding: false) else { return }
    UserDefaults.standard.set(data, forKey: defaultName)
}

第二个错误根本没有帮助。您可以使用 NSKeyedUnarchiver 的方法 unarchiveTopLevelObjectWithData ，它也会抛出：

func getBlood(forKey defaultName: String = "BloodDataKey") -> BloodData? {  // or forKey defaultName: String = dataKey
    guard let data = UserDefaults.standard.data(forKey: defaultName) else { return nil }
    guard let bloodData = (try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(data)) as? BloodData else { return nil }
    return computeData(data: bloodData)
}