问题
I need to group notifications from firebase about messages comes from users. Firebase push notification is grouping achieved by using **flutter_local_notification** plugin. This is done inside onMessage() callback set up during Firebase configuration. But when app is not in foreground this grouping and other customer styling can not be done. I had given "tag" field in notification section of Firebase push notification. This will show only one notification according to the tag.
But i need to add custom styling also when app not in foreground as like when the app is in foreground. How can i achieve this ?
来源：https://stackoverflow.com/questions/56076502/firebase-messaging-not-customizing-notification-when-app-is-not-in-foreground