navController 不更新 Jetpack Compose 中的位置

Question

我已经为我的新闻应用构建了 NavigationRail，它可以让我导航到搜索屏幕和主屏幕。我遇到一个问题，我传递给我的 NavigationRail 的 NavController 没有给我更新的当前位置，因此我的 navigationRail 图标没有显示它们在目的地时被选中。

我的导航栏代码是：

@Composable
fun NewsNavigationRail(
    navController: NavHostController
){

    val navigationItems = Destinations.values()

    NavigationRail{
        navigationItems.filter{
            it.icon != null && it.label != null
        }.forEach {
            NavigationRailItem(
                icon = { Icon(
                    it.icon!!,
                    contentDescription = it.name
                ) },


// problematic line --------------------------
                selected = navController.currentDestination?.route == it.route,
                onClick = {

                },
                label = { Text(it.label!!) }
            )
        }
    }
}

我的 NavigationHost 代码是：

@OptIn(ExperimentalMaterialApi::class)
@Composable
fun NavigationHost(){

    val navController = rememberNavController()

    Row {
        NewsNavigationRail(
            navController = navController
        )

        NavHost(navController = navController, startDestination = Destinations.HomeScreen.route){
            composable(Destinations.HomeScreen.route){
                val newsViewModel = hiltViewModel<NewsViewModel>()
                HomeScreen(newsViewModel, navController)
            }
            composable(
                "${Destinations.NewsScreen.route}/{url}",
                arguments = listOf(navArgument("url"){
                    type = NavType.StringType
                })
            ){
                val url = it.arguments?.getString("url")
                NewsScreen(url)
            }
            composable(Destinations.SearchScreen.route){
                val newsViewModel = hiltViewModel<NewsViewModel>()
                SearchScreen()
            }
        } 
    }
}

Answer 1

试试这个，

val navBackStackEntry by navController.currentBackStackEntryAsState() 
val currentRoute = navBackStackEntry?.destination?.route

navController 不更新 Jetpack Compose 中的位置

navController not updating locations in Jetpack Compose

android

kotlin

android-jetpack-compose