Issues with Jetpack Compose Navigation and ViewModel State Restoration on Android 14
I've searched everywhere and can't find a clear answer. I'm encountering a problem with state restoration when using Jetpack Compose Navigation along with ViewModels in my Android application targeting Android 14. I've implemented a simple navigation setup where I pass data between two composable screens using a shared ViewModel. However, I'm noticing that after the app is sent to the background and then resumed, the ViewModel state is not being restored correctly. The UI doesn't reflect the expected state, and I'm seeing a blank screen instead of the populated data. Here’s a simplified version of my setup: In my main activity, I set up the ViewModel: ```kotlin class MainActivity : ComponentActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContent { val viewModel: SharedViewModel = viewModel() NavHost(navController = rememberNavController(), startDestination = "screen1") { composable("screen1") { Screen1(viewModel) } composable("screen2") { Screen2(viewModel) } } } } } ``` In `Screen1`, I'm saving some state and navigating to `Screen2`: ```kotlin @Composable fun Screen1(viewModel: SharedViewModel) { val state by viewModel.state.collectAsState() Button(onClick = { viewModel.saveData("Hello from Screen 1"); navController.navigate("screen2") }) { Text("Go to Screen 2") } } ``` Then in `Screen2`, I'm trying to access that state: ```kotlin @Composable fun Screen2(viewModel: SharedViewModel) { val state by viewModel.state.collectAsState() Text(text = state ?: "No Data") } ``` I've added `@Persisted` to my ViewModel properties to handle state restoration. However, when I check the value after resuming the app, it appears to be `null`, which results in `"No Data"` being displayed instead of the expected value. I've tried using `rememberSavedInstanceState()` but that did not resolve the issue either. Has anyone faced a similar issue with Jetpack Compose and ViewModel state when the app is resumed? What additional steps should I take to ensure that the state is correctly restored? Any insights would be greatly appreciated! Is there a better approach? Any ideas how to fix this?