AudioFocusManager.java

/**
 * 用AudioManager获取音频焦点避免音视频声音重叠问题
 */
public class AudioFocusManager {

    private static final String TAG = "AudioFocusManager";

    private Context mContext;
    private AudioManager mAudioManager;
    private AudioManager.OnAudioFocusChangeListener mAudioFocusChangeListener;
    private AudioFocusRequest mAudioFocusRequest;

    public AudioFocusManager(Context context) {
        mContext = context;
    }

    /**
     * 请求音频焦点 设置监听
     */
    public int requestAudioFocus(final AudioListener audioListener) {
        if (mAudioManager == null) {
            mAudioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
        }
        if (mAudioFocusChangeListener == null) {
            mAudioFocusChangeListener = new AudioManager.OnAudioFocusChangeListener() {//监听器
                @Override
                public void onAudioFocusChange(int focusChange) {
                    Log.d(TAG, "onAudioFocusChange: " + focusChange);
                    switch (focusChange) {
                        case AudioManager.AUDIOFOCUS_GAIN:
                            Log.d(TAG, "onAudioFocusChange: AUDIOFOCUS_GAIN");
                            audioListener.play();
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS:
                            Log.d(TAG, "onAudioFocusChange: AUDIOFOCUS_LOSS");
                            audioListener.pause();
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                            Log.d(TAG, "onAudioFocusChange: AUDIOFOCUS_LOSS_TRANSIENT");
                            audioListener.pause();
                            break;
                        case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                            // ... pausing or ducking depends on your app
                            Log.d(TAG, "onAudioFocusChange: AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK");
                            audioListener.pause();
                            break;
                    }
                }
            };
        }

        int requestFocusResult = 0;
        if (mAudioManager != null) {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
                //下面两个常量参数试过很多都无效，最终反编译了其他app才搞定，汗~
                requestFocusResult = mAudioManager.requestAudioFocus(mAudioFocusChangeListener,
                        AudioManager.STREAM_MUSIC,
                        AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);
                Log.d(TAG, "requestAudioFocus: SDK_INT < 26 =" + requestFocusResult);
            } else {
                if (mAudioFocusRequest == null) {
                    mAudioFocusRequest = new AudioFocusRequest.Builder(AudioManager.AUDIOFOCUS_GAIN)
                            .setAudioAttributes(new AudioAttributes.Builder()
                                    .setUsage(AudioAttributes.USAGE_MEDIA)
                                    .setContentType(AudioAttributes.CONTENT_TYPE_MOVIE)
                                    .build())
                            .setAcceptsDelayedFocusGain(true)
                            .setOnAudioFocusChangeListener(mAudioFocusChangeListener)
                            .build();
                }
                requestFocusResult = mAudioManager.requestAudioFocus(mAudioFocusRequest);
                Log.d(TAG, "requestAudioFocus: SDK_INT >= 26 =" + requestFocusResult);
            }
        }
        return requestFocusResult;
    }

    /**
     * 暂停、播放完成或退到后台释放音频焦点
     * 应该先请求音频焦点
     */
    public int releaseAudioFocus() {
        if (mAudioManager == null) {
            mAudioManager = (AudioManager) mContext.getSystemService(Context.AUDIO_SERVICE);
        }

        int abandonFocusResult = 0;
        if (mAudioManager != null && mAudioFocusChangeListener != null) {
            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
                abandonFocusResult = mAudioManager.abandonAudioFocus(mAudioFocusChangeListener);
                Log.d(TAG, "releaseAudioFocus: SDK_INT < 26 =" + abandonFocusResult);
            } else {
                if (mAudioFocusRequest != null) {
                    abandonFocusResult = mAudioManager.abandonAudioFocusRequest(mAudioFocusRequest);
                    Log.d(TAG, "releaseAudioFocus: SDK_INT >= 26 =" + abandonFocusResult);
                }
            }
        }
        return abandonFocusResult;
    }

    public interface AudioListener {
        void play();

        void pause();
    }
}