file: /base/packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.javafunction: addStatusBarWindow()use: hide status bar with height as 0 show status bar with height as getStatusBarHeight()fix black bar in top when hide statusbarxml: /base/core/res/res/values/dimens.xmlchange line status_bar_height 25dip => 0dip