//去title 
requestWindowFeature(Window.FEATURE_NO_TITLE); 
//隐藏状态栏 
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN); 
//隐藏拟按键 
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);

  setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
  View decorView = getWindow().getDecorView();
  decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
      | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
      | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
      | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
      | View.SYSTEM_UI_FLAG_FULLSCREEN
      | View.SYSTEM_UI_FLAG_IMMERSIVE);