标签: android-jetpack-navigation

不知何故，构建崩溃了，并出现了与导航组件相关的奇怪错误，尽管它以前可以工作，但错误出在生成的类中，就我而言 NativeLanguageSelectionFragmentDirections

这是错误

e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (10, 16): Class 'GoToSelectLearningLangAction' is not abstract and does not implement abstract member public abstract val actionId: Int defined in androidx.navigation.NavDirections
e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (13, 12): 'getActionId' overrides nothing
e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (15, 12): 'getArguments' overrides nothing

这是导航图的代码

e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (10, 16): Class 'GoToSelectLearningLangAction' is not abstract and does not implement abstract member public abstract val actionId: Int defined in androidx.navigation.NavDirections
e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (13, 12): 'getActionId' overrides nothing
e: C:\Users\David\StudioProjects\android\app\build\generated\source\navigation-args\debug\com\linguistic\linguistic\framework\presentation\loginscreens\ui\main\NativeLanguageSelectionFragmentDirections.kt: (15, 12): 'getArguments' overrides nothing

我在用

 "androidx.navigation:navigation-fragment-ktx:2.3.5" …

我使用以下代码片段从一个可组合项导航到另一个可组合项，但它有一个默认的淡入淡出动画。我怎样才能删除它？我尝试使用空anim资源，但它不起作用。

navHostController.navigate(
    "destination_route",
    navOptions {
        popUpTo("this_route") {
            inclusive = true
        }
        anim {
            enter = R.anim.empty_animation
            exit = R.anim.empty_animation
            popEnter = R.anim.empty_animation
            popExit = R.anim.empty_animation
        }
    }
)

R.anim.empty_animation：

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <!--Empty to disable animation-->
</set>

我目前正在我的应用程序中实现导航组件，但似乎发现 NavHostFragment 无论我做什么都不起作用。

我已经尝试过重建、失效和重新启动、更改名称以及更新我的 Android Studio，但似乎没有任何效果。我认为这也是我尝试在 MainActivity.kt 文件中获取 NavController 时出错的原因，因为它返回 null。

安卓工作室 4.0.1 版

nav_graph.xml 图像：

导航图.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nav_graph"
    app:startDestination="@id/mainFragment">

    <fragment
        android:id="@+id/mainFragment"
        android:name="com.example.movieapp.ui.main.MainFragment"
        android:label="MainFragment">
        <action
            android:id="@+id/action_mainFragment_to_searchMovieFragment"
            app:destination="@id/searchMovieFragment" />
    </fragment>
    <fragment
        android:id="@+id/searchMovieFragment"
        android:name="com.example.movieapp.ui.search.SearchMovieFragment"
        android:label="SearchMovieFragment" />
</navigation>

main_activity.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.MainActivity">

    <include
        layout="@layout/appbar" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_host_fragment"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_graph" />

</androidx.constraintlayout.widget.ConstraintLayout>

主活动.kt

class MainActivity : AppCompatActivity() {

    private lateinit var toolbar: …

我想BluetoothDevice使用组合导航将 Parcelable 对象 ( ) 传递给可组合对象。

传递原始类型很容易：

composable(
  "profile/{userId}",
  arguments = listOf(navArgument("userId") { type = NavType.StringType })
) {...}

navController.navigate("profile/user1234")

但是我不能在路由中传递一个parcelable 对象，除非我可以将它序列化为一个字符串。

composable(
  "deviceDetails/{device}",
  arguments = listOf(navArgument("device") { type = NavType.ParcelableType(BluetoothDevice::class.java) })
) {...}

val device: BluetoothDevice = ...
navController.navigate("deviceDetails/$device")

上面的代码显然不起作用，因为它只是隐式调用toString().

有没有办法要么序列化Parcelable的String，所以我可以通过它的路线或通过导航参数作为比其他函数的对象navigate(route: String)？

当我双击同一项目或如果我很快进入每个可组合屏幕时，我会收到一条错误消息，我该如何解决此问题？我尝试改变一些东西，但我无法解决它，而且我找不到任何资源来解决这个问题。

底部导航实施

@Composable
fun BottomNav(
    navController: NavController,
    bottomNavState: MutableState<Boolean>,
) {

    val navItems = listOf(
        Screen.HomeScreen,
        Screen.BookmarkScreen,
        Screen.MyRecipesScreen,
        Screen.FavouriteScreen
    )

    AnimatedVisibility(
        visible = bottomNavState.value,
        enter = slideInVertically(initialOffsetY = { it }),
        exit = slideOutVertically(targetOffsetY = { it }),
        content = {
            BottomNavigation(
                backgroundColor = Color.White,
                elevation = 12.dp
            ) {

                val bottomNavBackStackEntry by navController.currentBackStackEntryAsState()
                val currentDestination = bottomNavBackStackEntry?.destination

                navItems.forEach { item ->

                    BottomNavigationItem(
                        icon = {
                            Icon(painter = painterResource(id = item.icon), contentDescription = "")
                        },
                        label = {
                            Text(text = …

我正在开发 Jetpack Compose Navigation 演示，并且有一个嵌套导航图，其中包含两个不同的嵌套路线以及每个嵌套路线的屏幕：

• 登录图
• 主图

登录图具有三种路线，用于显示三个不同的屏幕

• 路由“login”用于显示登录屏幕
• 路由“register”用于显示RegisterScreen
• 路由“recoverPassword”用于显示 RecoverPasswordScreen

主图有两个用于这些屏幕的路线

• 路由“home”以显示主屏幕
• 路由“设置”以显示设置屏幕

嵌套图创建在MainActivity.kt中调用

setContent {
        NavigationDemoTheme {

            val navController = rememberNavController()
            SetupNavGraph(navController = navController)
        }
    }

fun SetupNavGraph(navController: NavHostController) {
    NavHost(navController = navController, startDestination = "login_route")
    {
        loginGraph(navController = navController)
        mainGraph(navController = navController)
    }
}

fun NavGraphBuilder.loginGraph(navController: NavController) {
    navigation(startDestination = "login", route = "login_route") {
        composable(route = "login") {
            LoginScreen(navController = navController)
        }

        composable(route = "register") {
            RegisterScreen(navController = navController) …