Try this:
B4X:Dim no As NativeObject = WebView1 no.GetField("scrollView").SetField("scrollEnabled", False)
Dim wv As WebView
wv.Initialize("wv")
Dim no As NativeObject = wv
no.GetField("scrollView").SetField("showsHorizontalScrollIndicator", False)
no.GetField("scrollView").SetField("showsVerticalScrollIndicator", False)