Android clear backstack when leaving item tab BottomNavigation

Question

I am using the last navigation library (version 2.4.0) which include multiple backstacks with a bottom navigation view.

The default behavior is that each backstack is saved when user go back to a tab. I want to clear a backstack when the user leave a tab.

Based on this bottom nav with 3 tabs :

Tab1	Tab2	Tab3
ScreenA1	ScreenB1	ScreenC1
ScreenA2	ScreenB2	ScreenC2

From Tab1, if user:

• go to ScreenA2
• clic on Tab2 (ScreenB1 displayed)
• go back to Tab1
• here I want ScreenA1 and not ScreenA2 (default behavior of navigation library)

Thanks

Englishism

Answer 1

You can turn off multiple backstacks for tabs, as it was before lib version 2.4. For this you should change

navView.setupWithNavController(navController) 

to

NavigationUI.setupWithNavController(navView, navController, false) 

Pitzer

Saved me after decades of pure agony. No sure why this is not the top answer. – Nembutal

Answer 2

In your navigation file add these properties app:popUpTo and app:popUpToInclusive to the action which navigates to ScreenA2.

<action
    android:id="@+id/action_A1_to_A2"
    app:destination="@id/A2"
    app:popUpTo="@+id/A1"
    app:popUpToInclusive="true"/>

for more information look at this link: popUpTo example: circular logic

Mccoy

Thanks, the problem with this solution is that if I press back I lost the fragment (and I don't want it) – Englishism

Answer 3

Try invoking the below before you invoke the method to navigate to TAB1.

navController.popBackStack(R.id.ScreenA1, false);

This worked for me wherein I had a similar scenario to you.

Estrone

Please use a comment for the non-answering part I deleted. – Polymerization

Please also remind that using other options as a workaround to your account limitation is not allowed. You will unlock the comment option at 50 reputations). – Remex

This does not provide an answer to the question. Once you have sufficient reputation you will be able to comment on any post; instead, provide answers that don't require clarification from the asker. - From Review – Breda

Answer 4

I just done by onNavigationItemSelected Listener

1. The id in your navigation.xml and menu.xml should be different

2. When you handle the click action for particular item, try this

            R.id.home_bottom_item -> {navController.popBackStack();
            navController.navigate(R.id.home_bottom_item)
        }
   

Turn

Thanks but this is not working. – Englishism