在提供的设置中，我在Jetpack Compose应用程序中在屏幕1和屏幕2之间导航时遇到了一个问题。下面是问题的详细信息：
在屏幕1上，我有一个TextField，它更新viewModel，并在screen1_1中显示更新后的viewModel.uiState.name，因为viewModel状态是作为参数传入的

screen1_1(
    name = viewM.uiState.name
)

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当我单击屏幕2按钮时，它导航到屏幕2并显示通过navController传递的正确名称。navigate（“screen 2/${viewM.uiState.name}”）
但是，当我单击从屏幕2导航到屏幕1时，screen1_1重置为空？
当我导航回屏幕1时，如何保持viewModel状态

NavHost(navController = navController, startDestination = "screen1") {
    composable("screen1") { screen1(navController) }
    composable("screen2/{name}") { backStackEntry ->
        val name = backStackEntry.arguments?.getString("name") ?: ""
        screen2(navController, name)
    }
}
@Composable
fun screen1(navController: NavHostController) {
    val viewM: MyView = viewModel()
    Column {
        TextField(value = viewM.uiState.name, onValueChange = { viewM.updateName(it) })
        screen1_1(
            name = viewM.uiState.name
        )
        Button(onClick = { navController.navigate("screen2/${viewM.uiState.name}") }) {
            Text(text = "screen 2")
        }
    }
}
@Composable
fun screen1_1(name: String) { Text(text = "Hello1 $name!") }
@Composable
fun screen2(navController: NavHostController, name: String) {
    Column {
        Text(text = "Name: $name", style = MaterialTheme.typography.bodyLarge)
        Spacer(modifier = Modifier.height(16.dp))
        Button(onClick = { navController.navigate("screen1") }) {
            Text(text = "Navigate to Screen 1")
        }
    }
}
data class MyData(var name: String = "")
class MyView(private val state: SavedStateHandle) : ViewModel() {
    @OptIn(SavedStateHandleSaveableApi::class)
    var uiState by state.saveable {
        mutableStateOf(MyData(""))
    }
    private set
    fun updateName(name: String) {
        this.uiState = uiState.copy(name = name)
    }
}

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