BreadcrumbsView | Material Design Breadcrumbs Navigation Widget on Android | Navigation library

Given your navigation graph, there is no way to associate fragmentA2 with your menu item fragmentA, so fragmentA is not selected when you return to fragmentA2. As per this issue:

NavigationUI has always used the current destination and what graph it is part of as the source of truth for what tab should be selected.

This can be seen by calling navigate() to go to your SecondFragment - even though you haven't used the bottom nav button, the selected tab was changed because the current destination has changed to R.id.frag_second.

So when you navigate() to R.id.frag_hint via your button in HomeFragment, NavigationUI receives a callback that the current destination has changed to R.id.frag_hint. It looks at that NavDestination and notes that there's no menu item that matches R.id.frag_hint. It then looks at the destination's parent graph - your R.id.sample element. There's no menu item that matches that ID either, so NavigationUI can't associated that destination with any menu item and therefore simply does nothing. That is true on all versions of Navigation.

So what is different when you tap on a bottom navigation item? Well, nothing different from a NavigationUI perspective in fact: the exact same code runs and the current destination and what graph it is part of is the source of truth for what tab should be selected. In the Navigation 2.3.5, there was no state saved for each tab, so it only 'worked' because selecting a tab forced the ID of the current destination to match the destination of the menu item you just tapped.

So what you're seeing in your sample app is that there's no link between R.id.frag_hint and any menu item, which means NavigationUI does nothing. If you want to link R.id.frag_hint to your Home tab, then that's exactly what a nested navigation graph can be used for.

I.e., your navigation graph should instead look like:

You can pass the navigationContainerRef from the NavigationContainer to the Navigation comomponent to make the navigation object accessible.

Consider the following code snippet.

If you do not use the rules of material design, you should not have a theme that inherits from material design. Find the theme.xml according to the Android version of your studio and change the parent to Theme.AppCompat.Light.DarkActionBar.

You are passing the props for FileDetailScreen using the navigation route param props. If you have a screen

Usually I follow this pattern

Where I add HomeF in main container which includes all bottom nav tab, and all bottom nav tab will open in home container, and those fragment which are not part of bottom nav will open in main container. I generally add(not replace) all the fragments in main container and set add to back stack , so that if user goes from profile (home_container) to something in main container , while backstack we can pop the top fragment and user will be seeing profile.

You can pass your NavController to your TopAppBar and use navController.navigateUp() in the navigation icon.

If you want to show this icon only in some composables you can use a parameter, like canPop in the following example, and set it true in the composable where you want handle the back button.

The navigation stack of Shell has something special. Clear the navigation stack is not a good choice. We always use Routes to do the navigation for the Shell. You need to know which would generate the stack.

• A route, which defines the path to content that exists as part of the Shell visual hierarchy.
• A page. Pages that don't exist in the Shell visual hierarchy can be pushed onto the navigation stack from anywhere within a Shell application. For example, a details page won't be defined in the Shell visual hierarchy, but can be pushed onto the navigation stack as required.

For more details, please check the MS docs. https://docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/shell/navigation

When you press the back button, override the back button event and then judge the route to do the navigation would be better. Use the specific route name to go back.

Update:

After compilation the Navigation Bar that we call in Xamarin Forms, turns into the Action Bar for Android during runtime.

Set the toolbar after LoadApplication(new App()); in OnCreate of MainActivity.

At the core, React Navigation does not rerender the screen when a user navigates back to that screen for performance optimization and avoids unnecessary rerenders.

When required, They provide a useful hook to detect when screen is focused and run some side effects.

Let refactor code as below:

Navigation always crossfades destinations, so each screen will always recompose multiple times. This is expected as per the Thinking in Compose guide:

In some cases, a composable function might run for every frame of a UI animation. If the function performs expensive operations, like reading from device storage, the function can cause UI jank.

You aren't doing anything wrong (you aren't triggering side effects as part of composition), so your code is already fine.