当应用程序进入前台时，Flutter FirebaseMessaging 通知会自动删除

Question

当我点击应用程序（不是通知）时，每个通知都会自动删除。 这是一个大问题，当用户打开应用程序并删除所有通知时

Answer 1

当应用程序进入前台时，我发现了一个不需要的自动清理通知场景。它位于第 159 行 https://github.com/FirebaseExtended/flutterfire/blob/master/packages/firebase_messaging/ios/Classes/FirebaseMessagingPlugin.m

- (void)applicationDidBecomeActive:(UIApplication *)application {
  _resumingFromBackground = NO;
  // Clears push notifications from the notification center, with the
  // side effect of resetting the badge count. We need to clear notifications
  // because otherwise the user could tap notifications in the notification
  // center while the app is in the foreground, and we wouldn't be able to
  // distinguish that case from the case where a message came in and the
  // user dismissed the notification center without tapping anything.
  // TODO(goderbauer): Revisit this behavior once we provide an API for managing
  // the badge number, or if we add support for running Dart in the background.
  // Setting badgeNumber to 0 is a no-op (= notifications will not be cleared)
  // if it is already 0,
  // therefore the next line is setting it to 1 first before clearing it again
  // to remove all
  // notifications.
  application.applicationIconBadgeNumber = 1;
  application.applicationIconBadgeNumber = 0;
}

这似乎是徽章计数器的一种解决方法。我还开了一个issue：https://github.com/FirebaseExtended/flutterfire/issues/114