FCM notification messages不支持largeIcon或bigPicture.

FCM notification messages don't support the largeIcon or bigPicture.

如果您在后台需要它们，则可以使用FCM data message.

if you need them while in background you can use a FCM data message.

对于数据消息，总是调用onMessageReceived(message)方法，因此您可以使用message.getData()方法并创建自定义通知.

For data messages the onMessageReceived(message) method is always called, so you can use the message.getData() method and create your custom notification.

在此处阅读有关通知消息和数据消息的更多信息: https://firebase.google.com/docs/cloud-messaging/concept-options#notifications_and_data_messages

Read more about notification messages vs data messages here: https://firebase.google.com/docs/cloud-messaging/concept-options#notifications_and_data_messages