如何通过按下 swift 中的按钮取消 localNotification?

how to cancel a localNotification with the press of a button in swift?

我正在通过单击按钮安排基于 UILocalNotification 的位置。但是当我尝试通过再次单击同一个按钮来取消 localNotification 时,它不会取消通知。 我正在使用 UIApplication.sharedApplication().cancelLocalNotification(localNotification) 取消我预定的基于位置的本地通知。 我究竟做错了什么 ? 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 }

我应该在 else 块中输入什么,以便取消预定的通知。无法清除所有通知。 这是我触发本地通知的 didEnterRegion 代码块

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

不看代码的实现很难说。

所以你有一个

- IBAction methodName{

//scheduleNotification
//cancelNotification
}

差不多吧?如果是这样添加一个 bool so

Bool didCancel;

- IBAction methodName{

if didCancel == No{
//scheduleNotification
didCancel = YES;
}else if didCancel == YES{
//cancelNotifications
didCancel = NO;
}

如果您的情况可以接受,您可以尝试删除所有通知。 像这样:

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

或如 Logan 所述:

UIApplication.sharedApplication().cancelAllLocalNotifications()

或者如 Gerard Grundy 所说 Swift 4:

UNUserNotificationCenter.current().removeAllPendingNotificationRequests()

您可以在本地通知的用户信息中为键保存一个唯一值,并通过使用该键的值获取本地通知来取消它。 试试这个(Objective C):

NSArray *notifArray = [[UIApplication sharedApplication] scheduledLocalNotifications];
for (int i=0; i<[notifArray count]; i++)
{
    UILocalNotification* notif = [notifArray objectAtIndex:i];
    NSDictionary *userInfoDict = notif.userInfo;
    NSString *uniqueKeyVal=[NSString stringWithFormat:@"%@",[userInfoDict valueForKey:@"UniqueKey"]];
    if ([uniqueKeyVal isEqualToString:keyValToDelete])
    {
        [[UIApplication sharedApplication] cancelLocalNotification:notif];
        break;
    }
}

iOS10+Swift3.1

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

对于 Swift 3.0 和 iOS 10:

UNUserNotificationCenter.current().removeAllDeliveredNotifications()

您可以使用其标识符取消通知:

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