最近做了一个语音助手的应用，刚开始考虑的问题不全面，后来自己测试音乐App播放时再次打开语音助手音乐没有暂停播放，导致无法进行语音识别。意识到是音频焦点的问题，就想到AudioManager的requestAudioFocus();
开始请求，发现被弃用了，接着查看API
看到了
[requestAudioFocus](https://developer.android.google.cn/reference/android/media/AudioManager.html#requestAudioFocus(android.media.AudioManager.OnAudioFocusChangeListener,%20int,%20int))([AudioManager.<wbr>OnAudioFocusChangeListener](https://developer.android.google.cn/reference/android/media/AudioManager.OnAudioFocusChangeListener.html) l,<wbr> int streamType,<wbr> int durationHint)

This method was deprecated in API level 26. use [requestAudioFocus(AudioFocusRequest)](https://developer.android.google.cn/reference/android/media/AudioManager.html#requestAudioFocus(android.media.AudioFocusRequest))

下面是我写的获取音频焦点的工具类

import android.content.Context;
import android.media.AudioAttributes;
import android.media.AudioFocusRequest;
import android.media.AudioManager;
import android.os.Build;
import android.util.Log;
public class AudioHelper {
/**
 * 用AudioManager获取音频焦点避免音视频声音并发问题
 */
private static AudioManager mAudioManager;
private static AudioManager.OnAudioFocusChangeListener mAudioFocusChangeListener;
private static AudioFocusRequest mAudioFocusRequest;
private static final String TAG = "AudioHelper";

public static void init(Context context) {

    if (mAudioManager == null) {
        mAudioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
    }
    if (mAudioFocusChangeListener == null) {
        mAudioFocusChangeListener = new AudioManager.OnAudioFocusChangeListener() {//监听器
            @Override
            public void onAudioFocusChange(int focusChange) {
                Log.e(TAG, "onAudioFocusChange=========" + focusChange);
                switch (focusChange) {

                    case AudioManager.AUDIOFOCUS_GAIN:
                    case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT:
                    case AudioManager.AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK:
                         //继续播放
                        break;

                    case AudioManager.AUDIOFOCUS_LOSS:
                    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT:
                    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:
                        //暂停操作

                        break;
                    default:
                        break;
                }
            }
        };
    }
}

public static boolean isInit() {
    return null != mAudioManager && null != mAudioFocusChangeListener;
}


public static int requestTheAudioFocus() {
    if (Build.VERSION.SDK_INT < 8) {//Android 2.2开始(API8)才有音频焦点机制
        return 0;
    } else if (Build.VERSION.SDK_INT > 8 && Build.VERSION.SDK_INT <= 26) {
        if (isInit()) {
            int result = mAudioManager.requestAudioFocus(mAudioFocusChangeListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);
            return result;
        }
    } else if (Build.VERSION.SDK_INT > 26) {//API26 废弃了原来的获取方法
        if (isInit()) {
            //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~
            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();
            int result = mAudioManager.requestAudioFocus(mAudioFocusRequest);
      
            return result;
        }
    }
    return 0;

}

public static void abandonFocus() {
    if (isInit()) {
        if (Build.VERSION.SDK_INT > 8 && Build.VERSION.SDK_INT <= 26) {
            mAudioManager.abandonAudioFocus(mAudioFocusChangeListener);

        } else {
            if (Build.VERSION.SDK_INT > 26) {
                mAudioManager.abandonAudioFocusRequest(mAudioFocusRequest);
            }
        }

    }

}
  }