/**@param bMute 值為true時為關閉背景音樂。*/ @TargetApi(Build.VERSION_CODES.FROYO) public static boolean muteAudioFocus(Context context, boolean bMute) {   if(context == null){     Log.d("ANDROID_LAB", "context is null.");     return false;   }   if(!VersionUtils.isrFroyo()){     // 2.1以下的版本不支持下面的API：requestAudioFocus和abandonAudioFocus     Log.d("ANDROID_LAB", "Android 2.1 and below can not stop music");     return false;   }   boolean bool = false;   AudioManager am = (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);   if(bMute){     int result = am.requestAudioFocus(null,AudioManager.STREAM_MUSIC,AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);     bool = result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED;   }else{     int result = am.abandonAudioFocus(null);     bool = result == AudioManager.AUDIOFOCUS_REQUEST_GRANTED;   }   Log.d("ANDROID_LAB", "pauseMusic bMute="+bMute +" result="+bool);   return bool; }