I want to transparant statusbar.
I tried java code decorView.setSystemUiVisibility(SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN).
good! Status bar was transparent. but,
What is the red line at the bottom of the screen?
and I found it.
That is a homescreen background.
oh my god…
Why did this happen? and What should I do?
It probably happened because the layout system in Fuse has no way of knowing you changed the fullscreen / status bar settings. 
Instead of setting that flag directly you could try to set ShowStatusbar to false in the .unoproj
OR
you can include Android.StatusBarConfig and iOS.StatusBarConfig and set IsVisible to false.