how can I set the app icon badge

To set the app icon badge, you can use the UNUserNotificationCenter to manage notifications and update the badge count. Here's a basic example of how you can achieve this:

1. Request Notification Permissions: First, you need to request permission to display notifications.

   import UserNotifications
   
   UNUserNotificationCenter.current().requestAuthorization(options: [.badge, .sound, .alert]) { (granted, error) in
       if granted {
           print("Permission granted")
       } else if let error = error {
           print("Error: \(error.localizedDescription)")
       }
   }
   

2. Update the Badge Count: You can update the badge count by setting the badge property of a UNMutableNotificationContent object.

   let content = UNMutableNotificationContent()
   content.badge = NSNumber(value: 1) // Set the badge number
   
   let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
   let request = UNNotificationRequest(identifier: "badgeNotification", content: content, trigger: trigger)
   
   UNUserNotificationCenter.current().add(request) { (error) in
       if let error = error {
           print("Error: \(error.localizedDescription)")
       }
   }
   

3. Clear the Badge Count: To clear the badge count, you can set it to 0.

   UIApplication.shared.applicationIconBadgeNumber = 0
   

For more detailed information on how to extend your app's controls across the system, you can refer to the session Extend your app’s controls across the system (12:25).

If you need more information on how to integrate these features into your app, you might find the session Bring your app’s core features to users with App Intents (08:06) helpful.