Hello, I set a AVRoutePickerView in app, when I press the routePickerView, it shows nothing, I don't know what's wrong with my project. By the way, when I press MPVolumeView ,it can shows the system route alert picker. Anyone can help?

Hello, there. I use “AVPlayer.usesExternalPlaybackWhileExternalScreenIsActive = YES” to display video on some TV which support airplay like Apple TV. I often got the play/pause button shows the incorrect state when playing on TV but correctly in App video playing. So I'd like to get the playing state of Airplay Device to change the App play/pause button state, anyone can help?