is it possible to desing UI in native project and the rest pf the code in PCL for xamarin.forms ?

I am developing for Android and IOS and i want to ask which is the best approach to design the UI? there are not a lot of libraries that support UI in PCL project, and it seems better to design the UI natively for each the android and IOS.
Would this approach effect the business logic and data that i would develop in the PCL project and when i want to communicate with the UI would that mean i should write the code twice for each UI since the ID(s) are different for the UI views ?