Navigate from top app bar

This guide demonstrates how you can make the navigation icon in a top app bar perform navigation actions.

Example

The following snippet is a minimal example of how you can implement a top app bar with a functional navigation icon. In this case, the icon takes the user to their previous destination in the app:

@Composable
funTopBarNavigationExample(
navigateBack:()->Unit,
){
Scaffold(
topBar={
CenterAlignedTopAppBar(
title={
Text(
"Navigation example",
)
},
navigationIcon={
IconButton(onClick=navigateBack){
Icon(
imageVector=Icons.AutoMirrored.Filled.ArrowBack,
contentDescription="Localized description"
)
}
},
)
},
){innerPadding->
Text(
"Click the back button to pop from the back stack.",
modifier=Modifier.padding(innerPadding),
)
}
}AppBar.kt

Key points about the code

Note the following in this example:

The composable TopBarNavigationExample defines a parameter navigateBack of type () -> Unit.
It passes navigateBack for the navigationIcon parameter of CenterAlignedTopAppBar.

As such, whenever the user clicks the navigation icon in the top app back, it calls navigateBack().

Pass a function

This example uses a back arrow for the icon. As such, the argument for navigateBack() should take the user to the previous destination.

To do so, pass TopBarNavigationExample a call to NavController.popBackStack(). You do this where you build your navigation graph. For example:

NavHost(navController,startDestination="home"){
composable("topBarNavigationExample"){
TopBarNavigationExample{navController.popBackStack()}
}
// Other destinations...

Additional resources

For more information on how to implement navigation in your app, see the following series of guides: