设置适当的PlaybackState属性。下面是我的连续音频流的样子：

PlaybackState _transformEvent(PlaybackEvent event) {
    return PlaybackState(
      controls: [
        if (_player.playing) MediaControl.pause else MediaControl.play,
      ],
      androidCompactActionIndices: [MediaAction.play.index, MediaAction.pause.index],
      processingState: const {
        ProcessingState.idle: AudioProcessingState.idle,
        ProcessingState.loading: AudioProcessingState.loading,
        ProcessingState.buffering: AudioProcessingState.buffering,
        ProcessingState.ready: AudioProcessingState.ready,
        ProcessingState.completed: AudioProcessingState.completed,
      }[_player.processingState]!,
      playing: _player.playing,
    );
}