设置 HKQueryAnchor 时，如何绕过 iOS 12.0 中已弃用的“unarchiveObject(with:)”？

Question

我在创建HKAnchoredObjectQuery 时使用下面的代码设置HKQueryAnchor，但是'unarchiveObject(with:)' 已被弃用，我不知道如何使用新API 编写它？

private func getAnchor() -> HKQueryAnchor? {
        let encoded = UserDefaults.standard.data(forKey: AnchorKey)
        if(encoded == nil){
            return nil
        }
        
        let anchor = NSKeyedUnarchiver.unarchiveObject(with: encoded!) as? HKQueryAnchor
        return anchor
    }
    
    private func saveAnchor(anchor : HKQueryAnchor) {
        let encoded = NSKeyedArchiver.archivedData(withRootObject: anchor)
        defaults.setValue(encoded, forKey: AnchorKey)
        defaults.synchronize()
    }

Answer 1

尝试使用 JSONDecoder 和 JSONEncoder 将 data 与 HKQueryAnchor 实例联系起来，即

private func getAnchor() -> HKQueryAnchor? {
    guard let encoded = UserDefaults.standard.data(forKey: AnchorKey) else {
        return nil
    }

    let anchor = try? JSONDecoder().decode(HKQueryAnchor.self, from: encoded)
    return anchor
}

private func saveAnchor(anchor : HKQueryAnchor) {
    if let encoded = try? JSONEncoder().encode(anchor) {
        defaults.setValue(encoded, forKey: AnchorKey)
        defaults.synchronize()
    }
}

Answer 2

这是我根据 Martin R 的链接想出的，看起来好吗？

 private func getAnchor() -> HKQueryAnchor? {
    
       

 let encoded = UserDefaults.standard.data(forKey: AnchorKey)
    
    guard let unwrappedEncoded = encoded else { return nil }
    
    guard let anchor = try? NSKeyedUnarchiver.unarchiveTopLevelObjectWithData(unwrappedEncoded as Data) as? HKQueryAnchor
    else {
        return nil
    }
    
    return anchor
}

private func saveAnchor(anchor : HKQueryAnchor) {
    
    do {
        let encoded = try NSKeyedArchiver.archivedData(withRootObject: anchor, requiringSecureCoding: false)
        defaults.setValue(encoded, forKey: AnchorKey)
        defaults.synchronize()
    } catch {
        return
    }
}