AOSP 音频焦点接口调研

一 AOSP AudioMnager.java 中对外暴露的API

1 申请音频焦点

 public int requestAudioFocus(OnAudioFocusChangeListener l, int streamType, int durationHint)

    示例：

mAudioManager.requestAudioFocus(mAudioFocusListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);

public int requestAudioFocus(@NonNull AudioFocusRequest focusRequest) 

    示例：

mFocusRequest = new AudioFocusRequest

                     .Builder(focusRequest)