如何快速按下按钮取消localNotification？

Question

我正在计划一个基于位置的UILocalNotification，点击一个按钮。但是，当我试图通过再次单击相同的按钮来取消localNotification时，它不会取消通知。我正在使用UIApplication.sharedApplication().cancelLocalNotification(localNotification)取消基于本地通知的预定位置。我做错什么了？这是我的实现

@IBAction func setNotification(sender: UIButton!) {
    if sender.tag == 999 {
        sender.setImage(UIImage(named: "NotificationFilled")!, forState: .Normal)
        sender.tag = 0
        regionMonitor() //function where notification get scheduled

    } else {
        sender.setImage(UIImage(named: "Notification")!, forState: .Normal)
        sender.tag = 999 }

为了取消计划的通知，我应该输入什么其他块。无法清除所有通知。下面是触发本地通知的didEnterRegion块代码

func locationManager(manager: CLLocationManager!, didEnterRegion region: CLRegion!) {
    localNotification.regionTriggersOnce = true
    localNotification.alertBody = "Stack Overflow is great"
    UIApplication.sharedApplication().scheduleLocalNotification(localNotification)
    NSLog("Entering region")
}

Answer 1

如果这在上下文中是可以接受的，您可以尝试删除所有通知。如下所示：

for notification in UIApplication.sharedApplication().scheduledLocalNotifications as! [UILocalNotification] { 
  UIApplication.sharedApplication().cancelLocalNotification(notification)
}

或如Logan所述：

UIApplication.sharedApplication().cancelAllLocalNotifications()

或者正如Gerard Grundy为Swift 4所指出的：

UNUserNotificationCenter.current().removeAllPendingNotificationRequests()

Answer 2

可以使用通知的标识符取消通知：

let center = UNUserNotificationCenter.current()
center.removeDeliveredNotifications(withIdentifiers: [String])
center.removePendingNotificationRequests(withIdentifiers: [String])

Answer 3

iOS 10+ Swift 3.1的解决方案

let center = UNUserNotificationCenter.current()
center.removeAllDeliveredNotifications() // To remove all delivered notifications
center.removeAllPendingNotificationRequests()