SwiftUI Firebase 推送通知出現在應用內

Question

我剛剛在我的 SwiftUI 應用程序上設置了推送通知，我注意到當通知出現時，即使用戶在應用程序內，它也會出現！ （當應用程序的 state 處於活動狀態時）

這是我的設置：

class AppDelegate: NSObject, UIApplicationDelegate {
    func application(_ application: UIApplication,
                     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey : Any]? = nil) -> Bool {
        FirebaseApp.configure()
        UNUserNotificationCenter.current().delegate = self
        
        UNUserNotificationCenter.current().requestAuthorization(options: [.alert, .badge, .sound]) { (granted, error) in
        }
        
        application.registerForRemoteNotifications()
        Messaging.messaging().delegate = self
        
        return true
    }
}

extension AppDelegate: UNUserNotificationCenterDelegate {
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler:
        @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([[.banner, .sound, .badge]])
    }
    
    func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        didReceive response: UNNotificationResponse,
        withCompletionHandler completionHandler: @escaping () -> Void
    ) {
        completionHandler()
    }
    
    func application(_ application: UIApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
        Auth.auth().setAPNSToken(deviceToken, type: .unknown)
        Messaging.messaging().apnsToken = deviceToken
    }
    
    func application(_ application: UIApplication, didReceiveRemoteNotification notification: [AnyHashable : Any], fetchCompletionHandler completionHandler: @escaping (UIBackgroundFetchResult) -> Void) {
        Messaging.messaging().appDidReceiveMessage(notification)
        
        if (Auth.auth().canHandleNotification(notification)) {
            completionHandler(.noData)
            return
        }
    }
}

extension AppDelegate: MessagingDelegate {
    func messaging(_ messaging: Messaging, didReceiveRegistrationToken fcmToken: String?) {
        let tokenDict = ["token": fcmToken ?? ""]
        
        NotificationCenter.default.post(
            name: Notification.Name("FCMToken"),
            object: nil,
            userInfo: tokenDict)
    }
}

@main
struct popsterApp: App {
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    
    var body: some Scene {
        WindowGroup {
            ...
        }
    }
}

我不知道這是否重要，但我啟用了 swizzling？ 知道為什么會這樣嗎？

Answer 1

顯然，這段代碼負責在應用程序位於前台時顯示推送通知：

func userNotificationCenter(
        _ center: UNUserNotificationCenter,
        willPresent notification: UNNotification,
        withCompletionHandler completionHandler:
        @escaping (UNNotificationPresentationOptions) -> Void
    ) {
        completionHandler([[.banner, .sound, .badge]])
    }