使用 Jetpack 导航组件在一个屏幕上显示多个片段

Question

Two fragments

I'm using navigation component and trying to understand is it possible to have two or more opened fragments simultaneously like mail app (one fragment is a list of mails, another fragment is detailed mail view). It's desirable to have them inside another container parent fragment.

Answer 1

Yes, it's even recommended to design your app for multiple screen sizes . You can do so by creating alternative layouts , eg:

res/layout/fragment_items.xml          # Screens smaller than 600dp available width
res/layout-w600dp/fragment_items.xml   # Screens 600dp wide and bigger

where layout-w600dp/fragment_items.xml includes both fragments . This way you keep the same navigation destination and don't need to complicate things with conditional navigation .

It's desirable to have them inside another container parent fragment.

Depends. If you are going to use your list-fragment on multiple places, yes, because it would reduce duplicate code. If not, or your list-fragment is going to be different on multiple screens (you might add or hide some buttons) you don't need the container; and can just modify the fragment_items.xml layout for different screen sizes.