android ics TV / Tablet hide the navigation bar below

Recently doing set-top box applications , need to hide android 4.0.x below ( navigation bar + status bar ) , in the upper I tried a variety of methods, are listed below:

  getWindow().getDecorView().setSystemUiVisibility(View.STATUS_BAR_HIDDEN);
  getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LOW_PROFILE);
  getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
  getWindow().getDecorView().setSystemUiVisibility(4);
  

I would framework / base / packages / SystemUI following tricks ( this application directly to delete ) , and are done full-screen , but also can not use a lot of things to follow , such as wallpaper , USB, etc. have their own re- write , brother here urge Which expert guidance twelve , anxious , etc. ......
------ Solution ------------------- -------------------------
the activity can be set to full screen , there are two ways
1. in the manifest , set the activity 's theme is no titlebar, full screen and the like .
2. pass code is set , getWindow (). setFlags (WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
------ eference ----------------------------- ----------
Bangding this should not be difficult
------ eference --------------------- ------------------
above method does not work, last modified source : SystemUI, the problem is solved ...
------ eference ---------------------------------------
Will modify it under SystemUI was able to achieve hidden ah ?
------ eference --------------------------------------- < br>
I ask you is how to modify the source code ?