Android歌词秀设计思路（4）通用的音乐播放服务(下)(3)

                            break; 
                         default: 
                    } 
                } 
                 
            }; 
            mFocusable = focusable; 
        }else{ 
             mAudioFocus = Focused; // no focus feature, so we always "have" audio focus 
        } 
    } 
 
    /** Requests audio focus. Returns whether request was successful or not. */
    public boolean requestFocus() { 
        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED == 
            mAM.requestAudioFocus(mListener, AudioManager.STREAM_MUSIC, AudioManager.AUDIOFOCUS_GAIN); 
    } 
 
    /** Abandons audio focus. Returns whether request was successful or not. */
    public boolean abandonFocus() { 
        return AudioManager.AUDIOFOCUS_REQUEST_GRANTED == mAM.abandonAudioFocus(mListener); 
    } 
 
    public void giveUpAudioFocus() { 
        if (mAudioFocus == Focused  
                && android.os.Build.VERSION.SDK_INT >= 8
                && abandonFocus()) 
                mAudioFocus = NoFocusNoDuck; 
    } 
     
    public void tryToGetAudioFocus() { 
        if (mAudioFocus != Focused  
                && android.os.Build.VERSION.SDK_INT >= 8
                && requestFocus())