如何关闭来电媒体服务？我的 AudioManager 不工作

Question

我正在尝试将我的音频播放应用程序设置为在出现中断时停止播放。我按照 Android SDK 开发人员说明中有关设置 AudioFocusHelper 的说明进行操作，如下所示：

public class AudioFocusHelper  implements AudioManager.OnAudioFocusChangeListener {
    AudioManager mAudioManager;  
    Media_Service mService;
    Context mContext;
    public AudioFocusHelper(Context ctx, Media_Service svc) {  
        mAudioManager = (AudioManager) ctx.getSystemService(Context.AUDIO_SERVICE);        
        mService = svc;    
        }    

    public boolean requestFocus() {        
        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED ==            
                mAudioManager.requestAudioFocus(this, AudioManager.STREAM_MUSIC,            
                        AudioManager.AUDIOFOCUS_GAIN);    
        }    

    public boolean abandonFocus() {        
        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED ==            
                mAudioManager.abandonAudioFocus(this);    
        }    

    @Override    
    public void onAudioFocusChange(int focusChange) {        
        // let your service know about the focus change    
        mService.AudioFocus(focusChange);
    }
}

并且按照他们的建议，我让我的音频播放器在服务中运行。我的音频服务中有这个方法来响应音频焦点更改以暂停播放，但它不起作用——我不知道如何在虚拟机调试器中测试它，所以我无法真正看到传入的情况发生了什么称呼。自从我告诉它弹出祝酒词以来，它似乎没有被调用：

public void AudioFocus(int focusChange) {
    switch (focusChange) {        
    case AudioManager.AUDIOFOCUS_GAIN:            // resume playback           
        if (mMediaPlayer == null) 
            initMediaPlayer();            
        else if (!mMediaPlayer.isPlaying()) 
            mMediaPlayer.start();            
        //mMediaPlayer.setVolume(1.0f, 1.0f);            
        break;        
    case AudioManager.AUDIOFOCUS_LOSS:            // Lost focus for an unbounded amount of time: stop playback and release media player            
        if (mMediaPlayer.isPlaying()) {
            Toast.makeText(this,
                    "Playback interrupted by focus loss", Toast.LENGTH_SHORT).show();

            mMediaPlayer.stop();     
        }
        mMediaPlayer.release();            
        mMediaPlayer = null;            
        break;        
    case AudioManager.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 (mMediaPlayer.isPlaying()) {
            Toast.makeText(this,
                    "Playback paused by focus loss (transient)", Toast.LENGTH_SHORT).show();
            mMediaPlayer.pause();      
        }
        break;        
    case AudioManager.AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK:            // Lost focus for a short time, but it's ok to keep playing            
        // at an attenuated level            
        if (mMediaPlayer.isPlaying())  {
            Toast.makeText(this,
                    "Playback paused by focus loss (duck)", Toast.LENGTH_SHORT).show();
            mMediaPlayer.pause();            
            //mMediaPlayer.setVolume(0.1f, 0.1f); 
        }
        break;    
    }   
}

如果需要，我可以发布更多代码，看起来我已经发布了很多代码，而且我不想发布过多的代码。在我看来，我的 onAudioFocusChange 只是没有被调用。我在 Android 2.2 (minSDK 8) 上运行这个，因为 2.2 之前不支持这些功能。到处搜索提示，但我发现关于这个主题的信息很少，所以我希望有人能给我一些线索。

Answer 1

我也遇到了同样的问题，请记住，您需要在开始播放时调用 requestFocus() 方法，并在完成后调用放弃Focus() 方法。

Answer 2

我认为这可能有助于通过 DDMS 生成来电：Fake Incoming Call Android

希望您可以用它来调试你的应用程序。