Reminder reminder = ScheduledActionService.Find("MY REMINDER") as Reminder;

if ( reminder != null )

{

    ScheduledActionService.Remove("MY REMINDER");

}

reminder = new Reminder("MY REMINDER");

reminder.BeginTime = DateTime.Now + new TimeSpan(, 5, );

reminder.Content = "我的闹铃";

reminder.RecurrenceType = RecurrenceInterval.None;

reminder.NavigationUri = new Uri("/ReadyPage.xaml", UriKind.Relative);

ScheduledActionService.Add(reminder);