通知仅在应用程序处于后台或关闭时显示.

The notification only shows when the application is in background or closed .

当应用程序运行时，OnMessageReceived 会被触发，但我们看不到通知.

When the application is running , the OnMessageReceived would be triggered but we can't see the notification.

通知显示的原因是你在OnMessageReceived方法中发送Local Notification，解决问题，点击后不要忘记手动关闭.

The reason why the notification display is because you send Local Notification in OnMessageReceived method , to solve the problem , don't forget to dismiss it manually after clicking on it .

参考

https://***.com/a/63037820/8187800.