s3c210:

\frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\StatusBarService.java  !269

+ sb.setVisibility(View.GONE);
 

Mtk6572:

frameworks\base\packages\SystemUI\src\com\android\systemui\statusbar\phone\PhoneStatusBar.java !410

+ mStatusBarView.setVisibility(View.GONE);

按照以上方法更改之后,系统的状态条是隐藏了,但打电话的瞬间,某些全屏的界面会向下拉一个状态条的高度再恢复正常,修改状态栏高度为零即可解决,即在framework目录搜索到<dimen name="status_bar_height">25dip</dimen>和<dimen name="status_bar_icon_size">24dip</dimen>,把值改为0dip即可.