调用系统的媒体音量控制显示

调大声：

  
    

   
     1 
   
     AudioManager audioMa
   
     =
   
     (AudioManager)
   
     this
   
     .getSystemService(Context.AUDIO_SERVICE);

   
     2 
   
     audioMa.adjustStreamVolume(AudioManager.STREAM_MUSIC,AudioManager.ADJUST_RAISE,
  
    
  
    

   
     
   
     AudioManager.FX_FOCUS_NAVIGATION_UP);
  
    

调小声：

  
    

   
     1 
   
     AudioManager audioMa
   
     =
   
     (AudioManager)
   
     this
   
     .getSystemService(Context.AUDIO_SERVICE);

   
     2 
   
     audioMa.adjustStreamVolume(AudioManager.STREAM_MUSIC,AudioManager.ADJUST_LOWER,
  
    
  
    

   
     AudioManager.FX_FOCUS_NAVIGATION_UP);