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我正在尝试设置我的音频播放应用程序以在出现中断时停止播放。我按照 Android SDK 开发人员说明中关于设置 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);
    }
}

我的音频播放器按照他们的建议在服务中运行。我的音频服务中有这种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 vm 调试器中测试它所以我无法真正看到传入的情况称呼。它似乎没有被调用，因为我告诉它弹出祝酒词：

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;    
    }   
}

如有必要，我可以发布更多代码，似乎我已经发布了很多代码，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) 上运行它，因为 2.2 之前不支持这些功能。搜索了hi和low的提示，我发现关于这个主题的内容很少，所以我希望有人能给我一些线索。

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2 回答 2

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我遇到了同样的问题，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。

于 2011-08-26T18:12:45.617 回答
0

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

希望您可以使用它来调试您的应用程序。

于 2011-08-24T18:04:40.663 回答