除非重复为真，否则不会存储UNCalendarNotificationTrigger [英] UNCalendarNotificationTrigger doesn't get stored unless repeats is true

问题描述

我注意到如果我创建一个带有自定义日期的 UNCalendarNotificationTrigger ，除非我这样做，否则它不会被添加：
let trigger = UNCalendarNotificationTrigger（dateMatching：components，重复：** true **）

I've noticed that if I create an UNCalendarNotificationTrigger with a custom date it does't get added unless i put: let trigger = UNCalendarNotificationTrigger(dateMatching: components, repeats: **true**)

Apple示例是：

let date = DateComponents()
date.hour = 8
date.minute = 30 
let trigger = UNCalendarNotificationTrigger(dateMatching: date, repeats: true)

有意义重复== true。

which make sense to be repeats == true.

在我的场景中，我不需要创建一个重复多次的通知，但我需要在特定的日历日期（当然是将来）只发送一次多个通知..

In my scenario I dont need to create one notification that gets repeated many times, but I need multiple notificaitons fired only once on a specific calendar date (which is of course in the future)..

如果我在做：

let calendar = Calendar(identifier: .gregorian)

let formatter = DateFormatter()
formatter.dateFormat = "yyyyMMdd"
let newdate = formatter.date(from: "20161201")

let components = calendar.dateComponents(in: .current, from: newdate!)

let trigger = UNCalendarNotificationTrigger(dateMatching: components, repeats: false)

然后我总是收到0待处理的通知......

then i always get 0 pending notifications...

    UNUserNotificationCenter.current().getPendingNotificationRequests(completionHandler: { (notifications) in
                print("num of pending notifications \(notifications.count)")

            })

num of pending notification 0

有什么想法吗？

EDIT1：
添加其中一个答案指出的其他上下文。
我实际上是将请求添加到当前的UNUserNotificationQueue。

Adding other context as pointed out by one of the answers. I'm actually adding the request to the current UNUserNotificationQueue.

 let request = UNNotificationRequest(identifier: "future_calendar_event_\(date_yyyyMMdd)", content: content, trigger: trigger)

 UNUserNotificationCenter.current().add(request) { error in
      if let error = error {
           // Do something with error
           print(error.localizedDescription)
      } else {
           print("adding \((request.trigger as! UNCalendarNotificationTrigger).dateComponents.date)")
      }
 }

推荐答案

我有同样的问题，我现在解决它。这是由于dateComponents的年份。

I have the same problem and I solve it now. It is due to dateComponents' year.

为了解决这个问题，我测试了以下代码：

In order to solve this problem, I test the following code:

let notificationCenter = UNUserNotificationCenter.current()
let notificationDate = Date().addingTimeInterval(TimeInterval(10))
let component = calendar.dateComponents([.year,.day,.month,.hour,.minute,.second], from: notificationDate)
print(component)
let trigger = UNCalendarNotificationTrigger(dateMatching: component, repeats: false)
let request = UNNotificationRequest(identifier: item.addingDate.description, content: content, trigger: trigger)
self.notificationCenter.add(request){(error) in
    if let _ = error {
        assertionFailure()
    }
}

在控制台中，打印组件：

year: 106 month: 2 day: 14 hour: 12 minute: 3 second: 42 isLeapMonth: false 

在这种情况下，在待处理通知列表中找不到通知。

And in this case, the notification cannot be found in pending notification list.

let notificationDate = Date().addingTimeInterval(TimeInterval(10))
var component = calendar.dateComponents([.year,.day,.month,.hour,.minute,.second], from: notificationDate)
component.year = 2017
print(component)
let trigger = UNCalendarNotificationTrigger(dateMatching: component, repeats: false)
let request = UNNotificationRequest(identifier: item.addingDate.description, content: content, trigger: trigger)
self.notificationCenter.add(request){(error) in
    if let _ = error {
        assertionFailure()
    }
}

在控制台中，组件是：

year: 2017 month: 2 day: 14 hour: 12 minute: 3 second: 42 isLeapMonth: false 

然后可以在pe中找到此通知通知清单。

Then this notification can be found in pending notification list.

然后，我检查待处理的通知请求，以查找触发日期的年份组件是106还是2017：

And next, I check in the pending notification requests to find whether the trigger-date's year component is 106 or 2017:

notificationCenter.getPendingNotificationRequests(){[unowned self] requests in
    for request in requests {
        guard let trigger = request.trigger as? UNCalendarNotificationTrigger else {return}                       
        print(self.calendar.dateComponents([.year,.day,.month,.hour,.minute,.second], from: trigger.nextTriggerDate()!))                    
    }
}

我发现触发器的nextTriggerDate组件是：

I find the trigger's nextTriggerDate components are:

year: 106 month: 2 day: 14 hour: 12 minute: 3 second: 42 isLeapMonth: false 

结论

因此，如果您想将触发器的重复设置为false，应确保触发日期大于当前日期。

默认的dateComponents年份可能不合适，例如106.如果您希望通知2017年火灾，你应该明确地将组件年份设置为2017年。

The default dateComponents' year may be unsuitable, such as 106. If you want the notification to fire in 2017, you should set the components year to 2017 explicitly.

也许这是一个错误，因为我将触发器的dateComponents'年设置为2017年，但在nextTriggerDate的待处理通知请求中得到106.

Perhaps this is a bug, because I set trigger's dateComponents' year to 2017 but get 106 in nextTriggerDate of pending notification request.

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