Unexpected namespace prefix “app” found for tag RelativeLayout - Android?

Question

I need to use BottomSheetBehavior with ScrollView but it says to me :

Unexpected namespace prefix \"app\" found for tag RelativeLayout
         


        

Answer 1

For people using androidx, if you have child views from some androidx view, they should also be the androidx view to be able to recognize app namespace prefix. For example instead of:

you should use

This is not harmfull and it provides support for lower api version if you use some features that could not be supported (like tints for ImageView) :)