如何在特定日期之后停止触发预定的本地通知?

时间:2018-05-29 08:34:44

标签: ios xamarin.forms uilocalnotification localnotification unusernotificationcenter

我正在使用UNUserNotificationCenter在iOS上显示一些本地通知。这些是预定的通知。这是我的高级要求:(类似于iOS上的Reminders应用程序。您可以选择提醒时间,设置间隔(频繁)以及设置到期日期。

我有一个开始日期(2018年6月1日)和结束日期(2018年6月28日)和时间(例如,每天下午2:00)。这些本地通知应仅在指定日期之间触发。

这是我的代码:

var content = new UNMutableNotificationContent();
    content.Title = "Title";
    content.Subtitle = "Subtitle";
    content.Body = "Body";
    content.Badge = 1;
    content.CategoryIdentifier = categoryID;
    content.Sound = UNNotificationSound.Default;

    var d = new NSDateComponents {
        Hour = 14
    };
    //Repeat is true, so it will keep triggering when ever the hour reads 14
    var newTrigger = UNCalendarNotificationTrigger.CreateTrigger(d, true);
    var requestID = "notificationRequest";
    var request = UNNotificationRequest.FromIdentifier(requestID, content, newTrigger);

    //Here I set the Delegate to handle the user tapping on notification
    UNUserNotificationCenter.Current.Delegate = new CustomUNUserNotificationCenterDelegate();

    UNUserNotificationCenter.Current.AddNotificationRequest(request, (err) => {
        if (err != null) {
            // Report error
            System.Console.WriteLine("Error: {0}", err);
        } else {
            // Report Success
            System.Console.WriteLine("Notification Scheduled: {0}", request);
        }
    });

我正在检查WillPresentNotification方法中的条件:

public override void WillPresentNotification(UNUserNotificationCenter center, UNNotification notification, Action<UNNotificationPresentationOptions> completionHandler)  {
    DateTime StartDate = new DateTime(2018, 6, 1, 0, 0, 0);
    DateTime EndDate = new DateTime(2018, 6, 28, 0, 0, 0);
    if ((DateTime.Now > StartDate) && (DateTime.Now < EndDate)) {
        UIAlertView alertView = new UIAlertView();
        alertView.Message = "within the date range";
        alertView.AddButton("OK");
        alertView.Show();
        completionHandler(UNNotificationPresentationOptions.Alert | UNNotificationPresentationOptions.Sound | UNNotificationPresentationOptions.Badge);
    } else {
        var requests = new string[] { "notificationRequest" };
        UNUserNotificationCenter.Current.RemovePendingNotificationRequests(requests);
    }
}

如果应用程序位于前台并且通知自动取消,则此方法可以正常工作。但如果该应用程序被杀,那么这些通知仍然会继续。有没有办法检查何时在后台触发本地通知,以便可以检查上述逻辑并停止这些通知?

还有其他方法可以在6月28日下午2点准确地停止吗?

另外,我对iOS不太熟悉,UICalenderNotification触发器是否有到期日期?

我尝试使用ComponentsFromDateToDate进行实验,但通知仍在进行..

        //This is just test data
        var d = new NSDateComponents();
        NSCalendar currCal = new NSCalendar(NSCalendarType.Gregorian);
        var d1 = new NSDateComponents();
        d1.Day = 29;
        d1.Month = 5;
        d1.Year = 2018;
        d1.Hour = 12;
        d1.Minute = 58;
        d1.Second = 00;
        var d2 = new NSDateComponents();
        d2.Day = 29;
        d2.Month = 5;
        d2.Year = 2018;
        d2.Hour = 13;
        d2.Minute = 02;
        d2.Second = 00;
        currCal.ComponentsFromDateToDate(NSCalendarUnit.Second, d1, d2, NSCalendarOptions.None);
        d.Second = 10;
        d.Calendar = currCal;

我在这里做错了什么,或者应该考虑采取不同的做法?

我还在考虑使用后台提取,并且有一段代码可以检查日期范围的上述逻辑。

感谢任何帮助。谢谢!

1 个答案:

答案 0 :(得分:0)

我认为最佳解决方案是:使用UNNotificationRequest中的UNUserNotificationCenterUNCalendarNotificationTrigger添加到6.1-6.28,在6.28之后永远不会触发通知,因此这样做您无需手动删除该请求。

for(int i = 1; i < 29; i++)
{
    NSDateComponents d = new NSDateComponents() { Year = 2018, Month = 6,Day = i,Hour= 14 };
    UNCalendarNotificationTrigger trigger = UNCalendarNotificationTrigger.CreateTrigger(d, true);
    UNMutableNotificationContent content = new UNMutableNotificationContent() { Title = "xxx", Body = "xxx", CategoryIdentifier = "xxx" };
    UNNotificationRequest request = UNNotificationRequest.FromIdentifier(i.ToString(), content, trigger);
    UNUserNotificationCenter.Current.AddNotificationRequest(request,null);
}