如果答案不正确,防止警报操作关闭 UIAlertController - Swift 4

Prevent Alert action from dismissing the UIAlertController if incorrect answer - Swift 4

我有一个简单的 Parent Gateway 用于儿童友好游戏,使用 UIAlertController

当用户回答错误时 - 我不希望警报视图被关闭,此时我的设备会振动并且屏幕会抖动,但我无法让警报视图停留在屏幕上。

提供的答案在 Obj-C 中或涉及 禁用按钮 ,这显然不起作用,而其他答案可以不起作用 - 所以我希望会有更新的答案。

func parentGate () {

    var val1 = [1,2,3,4]
    var val2 = [5,6,7,8]
    let valIndex1 = Int(arc4random_uniform(UInt32(val1.count-1)))
    let valIndex2 = Int(arc4random_uniform(UInt32(val2.count-1)))

    accessAnswer = val1[valIndex1]+val2[valIndex2]

    let alertController = UIAlertController (title: "Parental Control", message: "This section is for Parents only, \nplease answer the question below: \nWhat is \(val1[valIndex1]) + \(val2[valIndex2])?", preferredStyle: .alert)
    let testAnswer = UIAlertAction(title: "OK", style: .default, handler: answerHandler)
    let cancelAnswer = UIAlertAction(title: "Cancel", style: .cancel, handler: nil)

    alertController.addTextField(configurationHandler: answerTextFieldResult)
    alertController.addAction(testAnswer)
    alertController.addAction(cancelAnswer)

    self.present(alertController, animated: true, completion: nil)

}

然后 testAnswer 处理程序如下所示:

func answerHandler (alert: UIAlertAction) {

    guard  let suppliedAnswer = answerTextField?.text,
        let answer = Int(suppliedAnswer) else {
            return
    }

    if answer == accessAnswer {
        print ("Good")

    } else {
        print ("Bad")
        AudioServicesPlayAlertSound(SystemSoundID(kSystemSoundID_Vibrate))
        self.view.shake(count: 3, for: 0.3, withTranslation: 3)
    }
}

如果您想查看 textField 处理程序目前的样子:

func answerTextFieldResult(textfield: UITextField) {
    answerTextField = textfield
    answerTextField?.placeholder = "Answer"
} 

你不能这样做。 这是系统行为 - 当您单击按钮时警报关闭并且您无法阻止它。

只有一个解决方案是创建一个看起来像原生的自定义视图控制器 UIAlertController