Swift 4 UNUserNotificationCenter持续时间(过去24小时内收到通知)

我正在使用UNUserNotificationCenter来发送通知,如下所示：

UNUserNotificationCenter.current().getDeliverednotifications { (notifications) in
    self.array = notifications
}

然后在viewWilldisappear上我清除applicationIconBadgeNumber,如下所示：

override func viewWilldisappear(_ animated: Bool) {
    super.viewWilldisappear(animated)
    UIApplication.shared.applicationIconBadgeNumber = 0
}

这样做不会让我的通知持续很长时间,是的,我希望看到通知后徽章编号为0,但我希望这些会持续24到48小时….我怎么能做到这一点？

获取通知的日期属性,并仅清除过去24小时内触发的通知.使用此功能：

func updateAppIcon() {
    UNUserNotificationCenter.current().getDeliverednotifications { (notifications) in            
        let past24hNotifications = notifications
            .filter { $0.date > Date().addingTimeInterval(-24 * 60 * 60)}
        dispatchQueue.main.async {
            UIApplication.shared.applicationIconBadgeNumber = past24hNotifications.count
        }
    }
}

并在AppDelegate的applicationWillResignActive(_ application :)中调用它