Ios 按下按钮时，当UIAlertController被解除时收到通知

我想在任何UIAlertController由于用户点击某个警报按钮而自动关闭（动画完成）之前和之后做一些操作并展示一些UI

我如何得到通知，用户按下了我的UIAlertController中的某个按钮，它将被解除，然后被解除

在文档中，建议不要将UIAlertController子类化。我仍然尝试过我的运气子类化，认为它可能在内部调用

func dismise（动画标志：Bool，completion:（（）->Void）？=nil）

。类似于

self.dismission（…

），但在iOS10上似乎不是这样

我还尝试在UIAlertAction处理程序中添加“手动”解除：

let alert = UIAlertController.init(...
let defaultAction = UIAlertAction(title: "OK", style: .default, handler: { action in
    alert.dismiss(animated: true, completion: { 
        print("Dismissed")
    })
})
alert.addAction(defaultAction)

但似乎在按下按钮后，但在调用处理程序之前，警报会被解除。无论如何，它不起作用。即使它起作用，记住将我的代码添加到每个UIAlertAction处理程序中也会有点麻烦

---

如果有任何想法，我将不胜感激。

尽管不建议使用子类，但您可以使用如下简单的子类：

class CustomAlertController: UIAlertController {

    var willDisappearBlock: ((UIAlertController) -> Void)?
    var didDisappearBlock: ((UIAlertController) -> Void)?

    override func viewWillDisappear(_ animated: Bool) {
        willDisappearBlock?(self)
        super.viewWillDisappear(animated)
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        didDisappearBlock?(self)
    }

}

let alert = CustomAlertController(title: "Alert", message: "This is an alert. Press Yes or No.", preferredStyle: .alert)
alert.willDisappearBlock = { alert in
    print("\(alert) will disappear")
}
alert.didDisappearBlock = { alert in
    print("\(alert) did disappear")
}

alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: { (yesAction) in
    print("User tapped Yes.")
}))
alert.addAction(UIAlertAction(title: "No", style: .cancel, handler: { (yesAction) in
    print("User tapped No.")
}))
present(alert, animated: true) {
    print("presentCompletion")
}

然后您可以这样使用它：

class CustomAlertController: UIAlertController {

    var willDisappearBlock: ((UIAlertController) -> Void)?
    var didDisappearBlock: ((UIAlertController) -> Void)?

    override func viewWillDisappear(_ animated: Bool) {
        willDisappearBlock?(self)
        super.viewWillDisappear(animated)
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        didDisappearBlock?(self)
    }

}

let alert = CustomAlertController(title: "Alert", message: "This is an alert. Press Yes or No.", preferredStyle: .alert)
alert.willDisappearBlock = { alert in
    print("\(alert) will disappear")
}
alert.didDisappearBlock = { alert in
    print("\(alert) did disappear")
}

alert.addAction(UIAlertAction(title: "Yes", style: .default, handler: { (yesAction) in
    print("User tapped Yes.")
}))
alert.addAction(UIAlertAction(title: "No", style: .cancel, handler: { (yesAction) in
    print("User tapped No.")
}))
present(alert, animated: true) {
    print("presentCompletion")
}

输出顺序如下：

当前完成

将消失

做过 消失

用户点击是

---

为什么不在“defaultAction”中完成所有需要的操作block？此block警报将被解除。@biloshkurskyi.ss正如我在问题中所写的那样-它容易出错，人们很容易忘记某个地方的block。谢谢。这似乎有效。我希望苹果不会在内部实现中更改任何内容。是否有任何方法获得UIAlertAction或

中按钮的索引将消失ear

？？