title: Swift using UNUserNotificationCenter when app is running
body: <p>I'm creating an alarm using UNUserNotificationCenter.App Works well when the app is in the background or exits
  However, there is no alarm if the app is running.</p>
  
  <p>I heard that there is no alarm if the app is running. Is it true?</p>
  
  <p>If not, how can I get an alarm when the app is running?</p>