Navigation rail

Rails provide access to destinations in apps that run on devices with large screens. You should use navigation rails for:

Top-level destinations that need to be accessible anywhere in an app
Three to seven main destinations
Tablet or desktop layouts

Figure 1. A navigation rail with four destinations and a floating action button.

This page shows you how to display rails in your app with related screens and basic navigation.

API surface

Use the NavigationRail composable with NavigationRailItem to implement a rail in your application. The NavigationRailItem represents a single rail item in the rail column.

NavigationRailItem includes the following key parameters:

selected: Determines whether the current rail item is visually highlighted.
onClick(): A required lambda function that defines the action to be performed when the user clicks on the rail item. This is where you typically handle navigation events, update the selected rail item state, or load corresponding content.
label: Displays text within the rail item. Optional.
icon: Displays an icon within the rail item. Optional.

Example: Rail-based navigation

The following snippet implements a navigation rail so users can navigate between different screens in an app:

@Composable
funNavigationRailExample(modifier:Modifier=Modifier){
valnavController=rememberNavController()
valstartDestination=Destination.SONGS
varselectedDestinationbyrememberSaveable{mutableIntStateOf(startDestination.ordinal)}
Scaffold(modifier=modifier){contentPadding->
NavigationRail(modifier=Modifier.padding(contentPadding)){
Destination.entries.forEachIndexed{index,destination->
NavigationRailItem(
selected=selectedDestination==index,
onClick={
navController.navigate(route=destination.route)
selectedDestination=index
},
icon={
Icon(
destination.icon,
contentDescription=destination.contentDescription
)
},
label={Text(destination.label)}
)
}
}
AppNavHost(navController,startDestination)
}
}Navigation.kt

Key points

NavigationRail displays a vertical column of rail items, with each item corresponding to a Destination.
val navController = rememberNavController() creates and remembers an instance of NavHostController, which manages the navigation within a NavHost.
var selectedDestination by rememberSaveable { mutableIntStateOf(startDestination.ordinal) } manages the state of the currently selected rail item.
- startDestination.ordinal gets the numerical index (position) of the Destination.SONGS enum entry.
When a rail item is clicked, navController.navigate(route = destination.route) is called to navigate to the corresponding screen.
The onClick lambda of the NavigationRailItem updates the selectedDestination state to visually highlight the clicked rail item.
It calls the AppNavHost composable, passing the navController and startDestination, to display the actual content of the selected screen.

Result

The following image shows the result of the previous snippet:

Figure 2. A navigation rail that contains 3 destinations with associated icons: Songs, Album, and Playlist.