有这么一种场景：你打开qq音乐、优酷客户端、视频播放的时候。这个时候突然来电显示了，此时所有的MediaPlayer相关的服务或者响应都进入“休眠”状态。那么，这个功能是怎么实现的呢？看到这篇文章的时候，原理其实很简单。只修要复制下面的d代码就能完成这个功能。

1、首先要创建一个AudioManager

//创建audioMangerAudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);int result = audioManager.requestAudioFocus(this, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN);

例如你在服务里面的onCreate方法里面完成的上面操作的。

2、让你的服务实现OnAudioFocusChangeListener接口：

例如：

public class AudioService extends Service implements OnAudioFocusChangeListener

3、实现该接口回调的方法。

/**---------------音频焦点处理相关的方法---------------**/@Overridepublic void onAudioFocusChange(int focusChange) {    switch (focusChange) {    case AudioManager.AUDIOFOCUS_GAIN://你已经得到了音频焦点。         System.out.println("-------------AUDIOFOCUS_GAIN---------------");        // resume playback        mPlayer.start();        mPlayer.setVolume(1.0f, 1.0f);        break;    case AudioManager.AUDIOFOCUS_LOSS://你已经失去了音频焦点很长时间了。你必须停止所有的音频播放        System.out.println("-------------AUDIOFOCUS_LOSS---------------");        // Lost focus for an unbounded amount of time: stop playback and release media player        if (mPlayer.isPlaying())            mPlayer.stop();        mPlayer.release();        mPlayer = null;        break;    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT://你暂时失去了音频焦点        System.out.println("-------------AUDIOFOCUS_LOSS_TRANSIENT---------------");        // Lost focus for a short time, but we have to stop        // playback. We don't release the media player because playback        // is likely to resume        if (mPlayer.isPlaying())            mPlayer.pause();        break;    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK://你暂时失去了音频焦点，但你可以小声地继续播放音频（低音量）而不是完全扼杀音频。        System.out.println("-------------AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK---------------");        // Lost focus for a short time, but it's ok to keep playing        // at an attenuated level        if (mPlayer.isPlaying())            mPlayer.setVolume(0.1f, 0.1f);        break;    }}

简单的三步，就完成了一个强大的功能。

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