在 swift 3 中将 [AnyObject] 转换为 [Int]

Question

我正在尝试创建一个数字数组并让用户将它们保存在他们的设备上。然而，当数据被保存时（通过使用 NSUserDefaults 方法）它被转换为一个 [AnyObject] 数组。我需要将它转换为 [Int] 的数组。这是我目前的做法：

class ProgressViewController: UIViewController {
  let kUserDefault = UserDefaults.standard
  var chartData = [Int]()
  override func viewWillAppear(_ animated: Bool) {
    let weighting = UserDefaults.standard.array(forKey: "chartData")
    footer1.text = "\((weighting))"
}
  @IBAction func AddGraphComponent(_ sender: UIButton) {
    var weighText:UITextField!
let alert = UIAlertController(title: "Enter new Weight!", message: "Please enter your Weight, followed by the date in which your weight was recorded", preferredStyle: UIAlertControllerStyle.alert)
alert.addTextField { (weighText) in
    weighText.placeholder = "Weight"
    weighText.keyboardType = UIKeyboardType.numberPad
}
alert.addTextField { (dateText) in
    dateText.placeholder = "Date (MM/YY)"
}
let confirmAction = UIAlertAction(title: "Save", style: UIAlertActionStyle.default) { (_) in
    let field = alert.textFields![0] as? UITextField
    let weigh = alert.textFields![1] as? UITextField

        if (field?.text)! == "" || (weigh?.text)! == "" {
            let alert1 = UIAlertController(title: "Error!", message: "Please fill in BOTH fields", preferredStyle: UIAlertControllerStyle.alert)
            alert1.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
            self.present(alert1, animated: true, completion: nil)
        }else {
            print((field?.text)!,(weigh?.text)!)
            let dataInt:Int = Int((field?.text!)!)!
            self.chartData.append(dataInt)
            self.chartLegend.append((weigh?.text)!)

            self.kUserDefault.set([self.chartData], forKey: "chartData") //as? [Int]
            self.kUserDefault.set([self.chartLegend], forKey: "chartLegend")
            self.kUserDefault.synchronize()
}
}
alert.addAction(UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: nil))
alert.addAction(confirmAction)
self.present(alert, animated: true, completion: nil)
 }

我试过 let weightData: Int = weighting as [Int] 但它崩溃并提示致命错误我试过 print("\(weighting?[0] as! Int)") 但它崩溃说 Could not cast value of type '__NSCFArray' (0x109f6ae88) to 'NSNumber' (0x108df0300).

当我尝试

let weighting = UserDefaults.standard.array(forKey: "chartData") as! [Int]
print("\((weighting[0]))")

我的应用崩溃并提示 Could not cast value of type '__NSCFArray' (0x108190e88) to 'NSNumber' (0x107016300)

有什么方法可以将保存的数组从 [AnyObject] 转换为 [String] 或 [Int] 吗？

Answer 1

行中

self.kUserDefault.set([self.chartData], forKey: "chartData")

您正在保存类型为 [[Int]] 的对象，因为 chartData 已经是一个数组。

删除括号

self.kUserDefault.set(self.chartData, forKey: "chartData")

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