Android FatalException 按 FloatingActionButton

Question

我正在实施 Android ToDoTask 应用程序并且 FloatingActionButton 出现错误，无法弄清楚如何修复它。 当我按下“添加任务”按钮时 - 我得到这个异常：

FATAL EXCEPTION: main
FATAL EXCEPTION: main
 Process: com.yuryigonin.composetodonotesapp, PID: 6280
 java.lang.IllegalArgumentException: Navigation destination that matches request NavDeepLinkRequest{ uri=android-app://androidx.navigation/task/-1 } cannot be found in the navigation graph NavGraph(0x0) startDestination={Destination(0x2f66e810) route=list/{action}}
  at androidx.navigation.NavController.navigate(NavController.kt:1664)
  at androidx.navigation.NavController.navigate(NavController.kt:1984)
  at androidx.navigation.NavController.navigate$default(NavController.kt:1979)
  at com.yuryigonin.composetodonotesapp.navigation.Screens$task$1.invoke(Screens.kt:15)
  at com.yuryigonin.composetodonotesapp.navigation.Screens$task$1.invoke(Screens.kt:14)
  at com.yuryigonin.composetodonotesapp.ui.screens.list.ListScreenKt$ListFab$1$1.invoke(ListScreen.kt:71)
  at com.yuryigonin.composetodonotesapp.ui.screens.list.ListScreenKt$ListFab$1$1.invoke(ListScreen.kt:70)
  at androidx.compose.foundation.ClickableKt$clickable$4$gesture$1$2.invoke-k-4lQ0M(Clickable.kt:153)
  at androidx.compose.foundation.ClickableKt$clickable$4$gesture$1$2.invoke(Clickable.kt:142)
  at androidx.compose.foundation.gestures.TapGestureDetectorKt$detectTapAndPress$2$1$1.invokeSuspend(TapGestureDetector.kt:222)
  at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
  at kotlinx.coroutines.DispatchedTaskKt.resume(DispatchedTask.kt:178)
  at kotlinx.coroutines.DispatchedTaskKt.dispatch(DispatchedTask.kt:166)
  at kotlinx.coroutines.CancellableContinuationImpl.dispatchResume(CancellableContinuationImpl.kt:397)
  at kotlinx.coroutines.CancellableContinuationImpl.resumeImpl(CancellableContinuationImpl.kt:431)
  at kotlinx.coroutines.CancellableContinuationImpl.resumeImpl$default(CancellableContinuationImpl.kt:420)
  at kotlinx.coroutines.CancellableContinuationImpl.resumeWith(CancellableContinuationImpl.kt:328)
  at androidx.compose.ui.input.pointer.SuspendingPointerInputFilter$PointerEventHandlerCoroutine.offerPointerEvent(SuspendingPointerInputFilter.kt:563)
  at androidx.compose.ui.input.pointer.SuspendingPointerInputFilter.dispatchPointerEvent(SuspendingPointerInputFilter.kt:455)
  at androidx.compose.ui.input.pointer.SuspendingPointerInputFilter.onPointerEvent-H0pRuoY(SuspendingPointerInputFilter.kt:468)
  at androidx.compose.ui.input.pointer.Node.dispatchMainEventPass(HitPathTracker.kt:310)
  at androidx.compose.ui.input.pointer.Node.dispatchMainEventPass(HitPathTracker.kt:297)
  at androidx.compose.ui.input.pointer.Node.dispatchMainEventPass(HitPathTracker.kt:297)
  at androidx.compose.ui.input.pointer.NodeParent.dispatchMainEventPass(HitPathTracker.kt:179)
  at androidx.compose.ui.input.pointer.HitPathTracker.dispatchChanges(HitPathTracker.kt:98)
  at androidx.compose.ui.input.pointer.PointerInputEventProcessor.process-BIzXfog(PointerInputEventProcessor.kt:97)
  at androidx.compose.ui.platform.AndroidComposeView.sendMotionEvent-8iAsVTc(AndroidComposeView.android.kt:1280)
  at androidx.compose.ui.platform.AndroidComposeView.handleMotionEvent-8iAsVTc(AndroidComposeView.android.kt:1230)
  at androidx.compose.ui.platform.AndroidComposeView.dispatchTouchEvent(AndroidComposeView.android.kt:1169)
  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3060)
  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2755)
  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3060)
  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2755)
  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3060)
  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2755)
  at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3060)
  at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2755)
  at com.android.internal.policy.DecorView.superDispatchTouchEvent(DecorView.java:465)
  at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1849)

The exception starts with Navigation component and then go to ListScreen composable function to FloatingActionButton component: java.lang.IllegalArgumentException: Navigation destination that matches request NavDeepLinkRequest{ uri=android-app://androidx.navigation/task/-1 } cannot be found在导航图中 NavGraph(0x0) startDestination={Destination(0x2f66e810) route=list/{action}}

屏幕：

class Screens(navController: NavHostController) {
    val list: (Action) -> Unit = { action ->
        navController.navigate(route = "list/${action.name}") {
            popUpTo(LIST_SCREEN) { inclusive = true }
        }
    }

    val task: (Int) -> Unit = { taskId ->
        navController.navigate(route = "task/$taskId")
    }
}

导航：

@ExperimentalMaterialApi
@Composable
fun SetupNavigation(
    navController: NavHostController,
    sharedViewModel: SharedViewModel
) {
    val screen = remember(navController) {
        Screens(navController = navController)
    }
    
    NavHost(navController = navController,
        startDestination = LIST_SCREEN
    ) {
        listComposable(
            navigateToTaskScreen = screen.task,
            sharedViewModel = sharedViewModel
        )
        taskComposable(
            navigateToListScreen = screen.list,
            sharedViewModel = sharedViewModel
        )
    }
}

ListScreen（我猜是Fab方法问题）：

@ExperimentalMaterialApi
@Composable
fun ListScreen(
    navigateToTaskScreen: (taskId: Int) -> Unit,
    sharedViewModel: SharedViewModel
) {

    LaunchedEffect(key1 = true) {
        sharedViewModel.getAllTasks()
    }

    val action by sharedViewModel.action

    val allTasks by sharedViewModel.allTasks.collectAsState()
    val searchAppBarState: SearchAppBarState
            by sharedViewModel.searchAppBarState

    val searchTextState: String by sharedViewModel.searchTextState
    val scaffoldState = rememberScaffoldState()

    DisplaySnackBar(
        scaffoldState = scaffoldState,
        handleDatabaseActions = { sharedViewModel.handleDatabaseActions(action = action) },
        taskTitle = sharedViewModel.title.value,
        action = action
    )

    Scaffold(
        scaffoldState = scaffoldState,
        topBar = {
            ListAppBar(
                sharedViewModel = sharedViewModel,
                searchAppBarState = searchAppBarState,
                searchTextState = searchTextState
            )
        },
        content = {
            ListContent(
                tasks = allTasks,
                navigateToTaskScreen = navigateToTaskScreen
            )
        },
        floatingActionButton = {
            ListFab(onFabClicked = navigateToTaskScreen)
        }
    )
}


@Composable
fun ListFab(
    onFabClicked: (taskId: Int) -> Unit
) {
    FloatingActionButton(
        onClick = {
            onFabClicked(-1)
        },
        backgroundColor = MaterialTheme.colors.fabBackgroundColor
    ) {
        Icon(
            imageVector = Icons.Filled.Add,
            contentDescription = stringResource(
                id = R.string.add_button
            ),
            tint = Color.White
        )
    }
}

Answer 1

问题出在常量文件中，其中常量：

const val TASK_SCREEN = "task/{taskId} " 的定义如下：

const val TASK_SCREEN = "list/{taskId} " 并且导航组件不知道正确的目的地。