如何从IOS通知中心一一读取通知后清除通知？

Question

在IOS应用中，是否有任何选项可以清除单个通知或在点击后将其标记为已读？我认为Apple不提供此功能。它们仅提供一次清除所有通知的功能。我搜索了很多，但没有找到任何解决方案。尽管我发现某些应用程序（例如Gmail）一次清除了一条通知。

提前感谢！

Answer 1

您可以在此属性中设置号码

 [UIApplication sharedApplication].applicationIconBadgeNumber

例如，将其减少一

[UIApplication sharedApplication].applicationIconBadgeNumber -= 1;

将其设置为特定值

[UIApplication sharedApplication].applicationIconBadgeNumber = 5;

Answer 2

我不知道如何处理推送通知，但是您可以像这样取消单个本地通知：

[[UIApplication sharedApplication] cancelLocalNotification:notification];

您可以获取对由App Delegate application:DidReceiveLocalNotification方法窃听的通知的引用。

Answer 3

请注意，此答案使用的是Swift 5。

要在点击时清除单个通知，您可以按照两个步骤进行操作：然后，清除匹配的通知。

我在其他地方回答了如何extend UNUserNotificationCenter to remove notifications和徽章。看起来像这样：

UNUserNotificationCenter

有了此扩展名，我们想响应

extension UNUserNotificationCenter {
    func decreaseBadgeCount(by notificationsRemoved: Int) {
        DispatchQueue.main.async {
            UIApplication.shared.applicationIconBadgeNumber -= notificationsRemoved
        }
    }

    func removeNotifications(_ notifications: [UNNotification], decreaseBadgeCount: Bool = true) {
        let identifiers = notifications.map { $0.request.identifier }
        UNUserNotificationCenter.current().removeDeliveredNotifications(withIdentifiers: identifiers)
        if decreaseBadgeCount {
            self.decreaseBadgeCount(by: notifications.count)
        }
    }

    func removeNotifications<T: Comparable>(whereKey key: AnyHashable, hasValue value: T, decreaseBadgeCount: Bool = true) {
        UNUserNotificationCenter.current().getDeliveredNotifications { notifications in
            let notificationsToRemove = notifications.filter {
                guard let userInfoValue = $0.request.content.userInfo[key] as? T else { return false }
                return userInfoValue == value
            }
            self.removeNotifications(notificationsToRemove, decreaseBadgeCount: decreaseBadgeCount)
        }
    }

    func removeNotifications(withThreadIdentifier threadIdentifier: String, decreaseBadgeCount: Bool = true) {
        UNUserNotificationCenter.current().getDeliveredNotifications { notifications in
            let notificationsToRemove = notifications.filter { $0.request.content.threadIdentifier == threadIdentifier }
            self.removeNotifications(notificationsToRemove, decreaseBadgeCount: decreaseBadgeCount)
        }
    }

    func removeNotification(_ notification: UNNotification, decreaseBadgeCount: Bool = true) {
        removeNotifications([notification], decreaseBadgeCount: decreaseBadgeCount)
    }
}

中的敲击，特别是AppDelegate方法：

userNotificationCenter(_:didReceive:withCompletionHandler:)

请注意，这仅适用于iOS 10及更高版本，并且不为

@available(iOS 10, *)
extension AppDelegate: UNUserNotificationCenterDelegate {
    func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        UNUserNotificationCenter.current().removeNotification(response.notification)
        completionHandler()
    }
}

参数提供false值，会将应用程序图标上的标志减少一。

编辑：不要忘记也将decreaseBadgeCount设置为AppDelegate委托：

UNUserNotificationCenter