Hide portion of mobile phone app page based on drop down choice

Question

So I have this idea regarding a part to the app that I am developing when the user goes in to section A where a drop down menu is. Once they choose their option from the menu, it triggers the revealing of the rest of the pages fields and such. But if you change the drop down choice, then it changes the page again based on the new choice. Now I know I can do this with HTML, but I was looking for other ideas more "native" to the devices programming language. Thanks for the help and feedback. :)

Answer 1

good idea