关闭当前呈现的所有 UIAlertControllers [英] Dismiss all UIAlertControllers currently presented

问题描述

有没有办法关闭当前显示的所有 UIAlertControllers?

Is there a way to dismiss all UIAlertControllers that are currently presented?

这特别是因为从我的应用程序的任何位置和任何状态，我都需要在按下推送通知时到达某个 ViewController.

This is specifically because from anywhere and any state of my app, I need to get to a certain ViewController when a push notification is pressed.

推荐答案

您可以将 UIAlertController 子类化，将 NSNotification 观察者附加到每个将触发UIAlertController 子类以关闭警报控制器，然后在您准备关闭时发布 NSNotification，例如:

You could subclass your UIAlertControllers, attach NSNotification observers to each which would trigger a method within the UIAlertController subclass to dismiss the alert controller, then post an NSNotification whenever you're ready to dismiss, ex:

class ViewController: UIViewController {
    func presentAlert() {
        // Create alert using AlertController subclass
        let alert = AlertController(title: nil, message: "Message.", preferredStyle: UIAlertControllerStyle.Alert)
        // Add observer to the alert
        NSNotificationCenter.defaultCenter().addObserver(alert, selector: Selector("hideAlertController"), name: "DismissAllAlertsNotification", object: nil)
        // Present the alert
        self.presentViewController(alert, animated: true, completion:nil)
    }
}

// AlertController subclass with method to dismiss alert controller
class AlertController: UIAlertController {
    func hideAlertController() {
        self.dismissViewControllerAnimated(true, completion: nil)
    }
}

然后在您准备关闭警报时发布通知(在本例中，当按下推送通知时):

Then post the notification whenever you're ready to dismiss the alert (in this case, when the push notification is pressed):

NSNotificationCenter.defaultCenter().postNotificationName("DismissAllAlertsNotification", object: nil)

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