如果应用程序在前台运行，如何知道在广播接收器中?

I am working in application that needs make a synchronization every night. I use Alarm Manager that calls a BroadcastReceiver at the hour that I want. The problem is that I cant make a synchronization if the application is running in foreground to avoid losing data. So I need to know in Broadcast Receiver if the app is running in foreground to cancel this synchronization.I am working in application that needs make a s