MainActivity.kt

MainActivity.kt

NavHost(navController, startDestination = SimpleScreenGraphNode.route) {
                composable(SimpleScreenGraphNode.route) {
                    SimpleScreen(navController = navController)
                }

                composable(ScreenWithArgumentGraphNode.route) {backStackEntry ->
                    val id = checkNotNull(backStackEntry.arguments?.getString(ScreenWithArgumentGraphNode.ARG_id))
                    val name = checkNotNull(backStackEntry.arguments?.getString(ScreenWithArgumentGraphNode.ARG_name))

                    ScreenWithArgument(navController = navController, id, name)
                }

                composable(ScreenWithOptionalArgumentsGraphNode.route) {backStackEntry ->
                    val id = checkNotNull(backStackEntry.arguments?.getString(ScreenWithOptionalArgumentsGraphNode.ARG_id))
                    val name = checkNotNull(backStackEntry.arguments?.getString(ScreenWithOptionalArgumentsGraphNode.ARG_name))
                    val nickName = backStackEntry.arguments?.getString(ScreenWithOptionalArgumentsGraphNode.ARG_OPTIONAL_nickName)
                    val age = backStackEntry.arguments?.getString(ScreenWithOptionalArgumentsGraphNode.ARG_OPTIONAL_age)
                    ScreenWithOptionalArguments(
                        name = name,
                        id = id,
                        nickName = nickName,
                        age = age
                    )
                }
            }