Screen empty after rotation - android

I need to handle screen rotation so I read about saved state and I tried to implement it bit I cant !
here is the fragment screen :
#AndroidEntryPoint
class ImagePickerFragment : Fragment() {
private lateinit var imagePickerBinding: FragmentImagePickerBinding
private val imagePickerViewModel: ImagePickerViewModel by viewModels {
SavedStateViewModelFactory(activity?.applicationContext as Application, this)
}
private lateinit var imagePickerAdapter: ImagePickerAdapter
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
imagePickerBinding = FragmentImagePickerBinding.inflate(inflater, container, false)
imagePickerBinding.lifecycleOwner = this
observeImageList()
observeSearchText()
observeImageClicked()
return imagePickerBinding.root
}
override fun onSaveInstanceState(outState: Bundle) {
imagePickerViewModel.trigger()
super.onSaveInstanceState(outState)
}
private fun observeImageList() {
imagePickerViewModel.observeImageListData.observe(
viewLifecycleOwner,
EventObserver { imageList ->
initializeImageList(imageList)
})
}
So here I should initialize viewModel with savedstate but this getting error :
09-23 13:10:38.621 26928-26928/com.payback.imagepicker E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.payback.imagepicker, PID: 26928
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.payback.imagepicker/com.payback.imagepicker.manager.base.MainActivity}: java.lang.RuntimeException: Cannot create an instance of class com.payback.imagepicker.presentation.ui.image_picker.ImagePickerViewModel
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
at android.app.ActivityThread.-wrap11(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.RuntimeException: Cannot create an instance of class com.payback.imagepicker.presentation.ui.image_picker.ImagePickerViewModel
at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.java:221)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:278)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:112)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:54)
at androidx.lifecycle.ViewModelLazy.getValue(ViewModelProvider.kt:41)
at com.payback.imagepicker.presentation.ui.image_picker.ImagePickerFragment.getImagePickerViewModel(ImagePickerFragment.kt:30)
at com.payback.imagepicker.presentation.ui.image_picker.ImagePickerFragment.observeImageList(ImagePickerFragment.kt:73)
at com.payback.imagepicker.presentation.ui.image_picker.ImagePickerFragment.onCreateView(ImagePickerFragment.kt:45)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2963)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:518)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1647)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3128)
at androidx.fragment.app.FragmentManager.dispatchViewCreated(FragmentManager.java:3065)
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:2988)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:546)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:282)
at androidx.fragment.app.FragmentStore.moveToExpectedState(FragmentStore.java:112)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1647)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3128)
at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3072)
at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:251)
at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:502)
at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:246)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1237)
at android.app.Activity.performStart(Activity.java:6253)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2379)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) 
at android.app.ActivityThread.-wrap11(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5417) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Caused by: java.lang.InstantiationException: java.lang.Class<com.payback.imagepicker.presentation.ui.image_picker.ImagePickerViewModel> has no zero argument constructor
at java.lang.Class.newInstance(Native Method)
at androidx.lifecycle.ViewModelProvider$NewInstanceFact
09-23 13:15:38.690 26928-26928/com.payback.imagepicker I/Process: Sending signal. PID: 26928 SIG: 9
And this is My view model :
#HiltViewModel
class ImagePickerViewModel #Inject constructor(
private val imageListUseCase: ImageListUseCase,
private val responseManager: ResponseManager,
private val savedStateHandle: SavedStateHandle
) : BaseViewModel() {
private val _observeImageListData :
MutableLiveData<Event<ArrayList<Image>>> = savedStateHandle.getLiveData("key")
fun trigger() {
savedStateHandle.set("key", _observeImageClicked.value)
}
Please can any one help me ? I cant understand it well or implement it right so what's wrong?

Related

Android ViewModelProvider causes application to immediately shut down

SOLVED - kapt "androidx.room:room-compiler:$room_version" missing in build.gradle
When i'm adding ViewModelProvider to my code, after opening a fragment in which it's added, my app immediately closes. Below i've provided the whole fragment class and error message. I've tracked the issue, and the application worked perfectly fine, before adding just one line with ViewModelProvider. Any idea why it's happening?
AddFragment
class AddFragment : Fragment() {
private var _binding: FragmentAddBinding? = null
private val binding get() = _binding!!
private lateinit var mTaskViewModel: TaskViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?,
): View? {
// Inflate the layout for this fragment
_binding = FragmentAddBinding.inflate(inflater, container, false)
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
mTaskViewModel = ViewModelProvider(this)[TaskViewModel::class.java]
binding.newTaskButton.setOnClickListener { insertToDatabase() }
}
private fun insertToDatabase() {
}
override fun onDestroyView() {
super.onDestroyView()
_binding = null
}
}
ERROR
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.randoo, PID: 25691
java.lang.RuntimeException: Cannot create an instance of class com.example.randoo.data.TaskViewModel
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:320)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:304)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:278)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153)
at com.example.randoo.fragments.AddFragment.onViewCreated(AddFragment.kt:33)
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3128)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:552)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:261)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1890)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1814)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1751)
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:538)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7839)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:312)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:304) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:278) 
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153) 
at com.example.randoo.fragments.AddFragment.onViewCreated(AddFragment.kt:33) 
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3128) 
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:552) 
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:261) 
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1890) 
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1814) 
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1751) 
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:538) 
at android.os.Handler.handleCallback(Handler.java:938) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loopOnce(Looper.java:201) 
at android.os.Looper.loop(Looper.java:288) 
at android.app.ActivityThread.main(ActivityThread.java:7839) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003) 
Caused by: java.lang.RuntimeException: cannot find implementation for com.example.randoo.data.TaskDatabase. TaskDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:100)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1486)
at com.example.randoo.data.TaskDatabase$Companion.getDatabase(TaskDatabase.kt:28)
at com.example.randoo.data.TaskViewModel.<init>(TaskViewModel.kt:17)
at java.lang.reflect.Constructor.newInstance0(Native Method) 
at java.lang.reflect.Constructor.newInstance(Constructor.java:343) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:312) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:304) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:278) 
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.kt:128) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:187) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:153) 
at com.example.randoo.fragments.AddFragment.onViewCreated(AddFragment.kt:33) 
at androidx.fragment.app.Fragment.performViewCreated(Fragment.java:3128) 
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:552) 
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:261) 
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1890) 
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1814) 
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1751) 
at androidx.fragment.app.FragmentManager$5.run(FragmentManager.java:538) 
at android.os.Handler.handleCallback(Handler.java:938) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loopOnce(Looper.java:201) 
at android.os.Looper.loop(Looper.java:288) 
at android.app.ActivityThread.main(ActivityThread.java:7839) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
TaskDatabase 
#Database(entities = [Task::class], version = 1, exportSchema = false)
abstract class TaskDatabase : RoomDatabase() {
abstract fun taskDao(): TaskDao
companion object {
#Volatile
private var INSTANCE: TaskDatabase? = null
fun getDatabase(context: Context): TaskDatabase{
val tempInstance = INSTANCE
if (tempInstance != null){
return tempInstance
}
synchronized(this){
val instance = Room.databaseBuilder(
context.applicationContext,
TaskDatabase::class.java,
"task_database"
).build()
INSTANCE = instance
return instance
}
}
}
}

Unable to create androidviewmodel instance [duplicate]

This question already has answers here:
Android room persistent: AppDatabase_Impl does not exist
(29 answers)
Closed 12 months ago.
I am working on a notes application with room and ViewModel but while initializing the ViewModel inside activity, I am getting this
java.lang.RuntimeException: Cannot create an instance of class package.notes.homeScreen.HomeScreenVM
here is my main activity
class MainActivity : AppCompatActivity() {
private lateinit var binding: ActivityMainBinding
private lateinit var viewModel: HomeScreenVM
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setUI()
setViewModel()
}
private fun setUI() {
binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)
}
private fun setViewModel() {
viewModel = ViewModelProvider(this, HomeScreenViewModelFactory(this.application))[HomeScreenVM::class.java]
}
}
and ViewModel is like-
class HomeScreenVM(application: Application) : AndroidViewModel(application) {
//some methods
}
and my viewmodelfactory is like-
class HomeScreenViewModelFactory(private val application: android.app.Application) : ViewModelProvider.AndroidViewModelFactory(application) {
#Suppress("UNCHECKED_CAST")
override fun <T : ViewModel> create(modelClass: Class<T>): T {
if (modelClass.isAssignableFrom(HomeScreenVM::class.java))
return HomeScreenVM(application) as T
throw IllegalArgumentException("Unknown model class")
}
}
I don't know where the problem is. Help me.
Thanks in advance.
Update:-
full stacktrace is
Process: com.nitkkr.sanjay.notes, PID: 32750
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.nitkkr.sanjay.notes/com.nitkkr.sanjay.notes.homeScreen.MainActivity}: java.lang.RuntimeException: Cannot create an instance of class com.nitkkr.sanjay.notes.homeScreen.HomeScreenVM
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3536)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3708)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2143)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:236)
at android.app.ActivityThread.main(ActivityThread.java:8087)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967)
Caused by: java.lang.RuntimeException: Cannot create an instance of class com.nitkkr.sanjay.notes.homeScreen.HomeScreenVM
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:315)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:273)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:182)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:151)
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.setViewModel(MainActivity.kt:29)
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.onCreate(MainActivity.kt:17)
at android.app.Activity.performCreate(Activity.java:8157)
at android.app.Activity.performCreate(Activity.java:8129)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1310)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3509)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3708) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2143) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:236) 
at android.app.ActivityThread.main(ActivityThread.java:8087) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967) 
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:343)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:307)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:273) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:182) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:151) 
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.setViewModel(MainActivity.kt:29) 
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.onCreate(MainActivity.kt:17) 
at android.app.Activity.performCreate(Activity.java:8157) 
at android.app.Activity.performCreate(Activity.java:8129) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1310) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3509) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3708) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2143) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:236) 
at android.app.ActivityThread.main(ActivityThread.java:8087) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967) 
Caused by: java.lang.RuntimeException: cannot find implementation for com.nitkkr.sanjay.notes.data.database.NoteDatabase. NoteDatabase_Impl does not exist
at androidx.room.Room.getGeneratedImplementation(Room.java:100)
at androidx.room.RoomDatabase$Builder.build(RoomDatabase.java:1486)
at com.nitkkr.sanjay.notes.data.database.NoteDatabase$Companion.getInstance(NoteDatabase.kt:24)
at com.nitkkr.sanjay.notes.data.database.NoteRepository.<init>(NoteRepository.kt:11)
at com.nitkkr.sanjay.notes.homeScreen.HomeScreenVM.<init>(HomeScreenVM.kt:12)
at java.lang.reflect.Constructor.newInstance0(Native Method) 
at java.lang.reflect.Constructor.newInstance(Constructor.java:343) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:307) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.kt:273) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:182) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.kt:151) 
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.setViewModel(MainActivity.kt:29) 
at com.nitkkr.sanjay.notes.homeScreen.MainActivity.onCreate(MainActivity.kt:17) 
at android.app.Activity.performCreate(Activity.java:8157) 
at android.app.Activity.performCreate(Activity.java:8129) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1310) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3509) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3708) 
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2143) 
at android.os.Handler.dispatchMessage(Handler.java:106) 
at android.os.Looper.loop(Looper.java:236) 
at android.app.ActivityThread.main(ActivityThread.java:8087) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:656) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:967) 
viewModel =ViewModelProvider(
this,
HomeScreenViewModelFactory(application)
).get(HomeScreenVM::class.java)
Use this i hope it will work.

Can Not create Instance of ViewModel class

I am working with MVVM architecture and I don't get it why am I having this error? My other classes have the same structure and they are working perfectly fine. Below i have shared the code for both my Fragment Class and the ViewModel Class along with the error
Error
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.beyond.sellandtrack, PID: 5380
java.lang.RuntimeException: Cannot create an instance of class com.beyond.sellandtrack.screens.dashboard.DashboardViewModel
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:275)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:106)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185)
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150)
at com.beyond.sellandtrack.screens.dashboard.DashboardFragment.onCreateView(DashboardFragment.kt:33)
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698)
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320)
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187)
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849)
at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413)
at android.os.Handler.handleCallback(Handler.java:809)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:166)
at android.app.ActivityThread.main(ActivityThread.java:7555)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Constructor.newInstance0(Native Method)
at java.lang.reflect.Constructor.newInstance(Constructor.java:334)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:267)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:106) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150) 
at com.beyond.sellandtrack.screens.dashboard.DashboardFragment.onCreateView(DashboardFragment.kt:33) 
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698) 
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320) 
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187) 
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224) 
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997) 
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953) 
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849) 
at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413) 
at android.os.Handler.handleCallback(Handler.java:809) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:166) 
at android.app.ActivityThread.main(ActivityThread.java:7555) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963) 
Caused by: kotlin.KotlinNullPointerException
at com.beyond.sellandtrack.screens.dashboard.DashboardViewModel.<init>(DashboardViewModel.kt:20)
at java.lang.reflect.Constructor.newInstance0(Native Method) 
at java.lang.reflect.Constructor.newInstance(Constructor.java:334) 
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:267) 
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:106) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:185) 
at androidx.lifecycle.ViewModelProvider.get(ViewModelProvider.java:150) 
at com.beyond.sellandtrack.screens.dashboard.DashboardFragment.onCreateView(DashboardFragment.kt:33) 
at androidx.fragment.app.Fragment.performCreateView(Fragment.java:2698) 
at androidx.fragment.app.FragmentStateManager.createView(FragmentStateManager.java:320) 
at androidx.fragment.app.FragmentManager.moveToState(FragmentManager.java:1187) 
at androidx.fragment.app.FragmentManager.addAddedFragments(FragmentManager.java:2224) 
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1997) 
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1953) 
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:1849) 
at androidx.fragment.app.FragmentManager$4.run(FragmentManager.java:413) 
at android.os.Handler.handleCallback(Handler.java:809) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:166) 
at android.app.ActivityThread.main(ActivityThread.java:7555) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:469) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:963) 
I/Process: Sending signal. PID: 5380 SIG: 9
Disconnected from the target VM, address: 'localhost:8600', transport: 'socket'
Fragment Class
class DashboardFragment : Fragment() {
private lateinit var dashboardViewModel: DashboardViewModel
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val binding = DataBindingUtil.inflate<FragmentDashboardBinding>(
inflater,R.layout.fragment_dashboard,container,false
)
dashboardViewModel= ViewModelProvider(this).get(DashboardViewModel::class.java)
ViewModel Class
class DashboardViewModel(application: Application) : AndroidViewModel(application) {
lateinit var user: User
private var auth : FirebaseAuth = FirebaseAuth.getInstance()
private var repository: Repository = Repository()
init {
user = repository.getUserData()!!
}
You need to check if the getUserData is not null. in init block
init {
user = repository.getUserData()!! //you are forcefully marking this as non null
}
check if the getUserData() is returning null here or not. Which is null most probably and that's why it's failing
I think you should try Koin to inject and create instance of ViewModel.
Its easy to use and syntax is brief.
https://insert-koin.io/.
// Injected by constructor
class MyViewModel(val repo : MyRepository) : ViewModel()
// declared ViewModel using the viewModel keyword
val myModule : Module = module {
viewModel { MyViewModel(get()) }
single { MyRepository() }
}
// Just get it
class MyActivity() : AppCompatActivity() {
// lazy inject MyViewModel
val myViewModel : MyViewModel by viewModel()
}
I think your DashboardViewModel class should extending from ViewModel() not AndroidViewModel()
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.2.0"
import androidx.lifecycle.ViewModel
class DashboardViewModel : ViewModel()

Problem with constant Array with fragment in Kotlin

I'm new to Kotlin and I created a constant array to use in spinner inside of fragment. When I try to run the code, the app crashes. I've tried to find a solution, but couldn't.
The really weird part, it worked perfectly yesterday when I worked on it, and today it's crashes.
this is my fragment:
class PersonalDetailsFragment : Fragment() {
private lateinit var listener: OnChangeFragmentListener
override fun onAttach(context: Context?) {
super.onAttach(context)
listener = getListenerOrThrowException(OnChangeFragmentListener::class.java)
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
// Inflate the layout for this fragment
val v = inflater.inflate(R.layout.fragment_personal_deatails, container, false)
v.spinnerAge.adapter = ArrayAdapter<Int>(context, android.R.layout.simple_list_item_1, LIST_AGE)
v.btnGoDetails.setOnClickListener { listener.changeFragment() }
return v
}
this is my Constant class:
class Constant {
companion object {
#JvmField val LIST_AGE = getAgeList()
private fun getAgeList(): Array<Int?> {
val array = arrayOfNulls<Int>(83)
for (i in array.indices){
var age = i + 17
array[i] = age
}
return array
}
}
Error Log:
2019-06-06 19:02:53.732 18331-18331/com.eldareini.kotlin.meet4match
E/tlin.meet4matc: No package ID 7f found for ID 0x7f0d0044.
2019-06-06 19:02:53.732 18331-18331/com.eldareini.kotlin.meet4match
D/AndroidRuntime: Shutting down VM
2019-06-06 19:02:53.736 18331-18331/com.eldareini.kotlin.meet4match E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.eldareini.kotlin.meet4match, PID: 18331
java.lang.ExceptionInInitializerError
at com.eldareini.kotlin.meet4match.signup.PersonalDetailsFragment.onCreateView(PersonalDetailsFragment.kt:57)
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460)
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784)
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852)
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802)
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625)
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411)
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366)
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273)
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:733)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: android.content.res.Resources$NotFoundException: String resource ID #0x7f0d0044
at android.content.res.Resources.getText(Resources.java:348)
at android.content.res.Resources.getString(Resources.java:441)
at com.eldareini.kotlin.meet4match.Constant.<clinit>(Constant.kt:69)
at com.eldareini.kotlin.meet4match.signup.PersonalDetailsFragment.onCreateView(PersonalDetailsFragment.kt:57) 
at android.support.v4.app.Fragment.performCreateView(Fragment.java:2439) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1460) 
at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1784) 
at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1852) 
at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:802) 
at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2625) 
at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2411) 
at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2366) 
at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2273) 
at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:733) 
at android.os.Handler.handleCallback(Handler.java:873) 
at android.os.Handler.dispatchMessage(Handler.java:99) 
at android.os.Looper.loop(Looper.java:193) 
at android.app.ActivityThread.main(ActivityThread.java:6669) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

NoSuchMethodException: <init> [class android.app.Application]

I am trying to switch my app from Loaders to Room and ViewModels. I have written my own App class:
class App : Application() {
lateinit var database: AppDatabase
private set
override fun onCreate() {
super.onCreate()
instance = this
database = Room.databaseBuilder(this, AppDatabase::class.java, AppDatabase.NAME)
.build()
}
companion object {
lateinit var instance : App
}
}
And my view model:
open class BaseViewModel<TEntity, TDao: BaseDao<TEntity>, TRepo : Repository<TEntity, TDao>>(
app: App, protected val repository: TRepo) : AndroidViewModel(app) {
fun insert(entity: TEntity) {
repository.insert(entity)
}
fun update(entity: TEntity) {
repository.update(entity)
}
fun delete(entity: TEntity) {
repository.delete(entity)
}
}
class TimetableViewModel(app: App) : BaseViewModel<Timetable, TimetableDao, TimetableRepository>(
app, TimetableRepository(app.database)) {
internal val all: LiveData<List<Timetable>> = repository.getAll()
}
In MainActivity.onCreate() I initialize my TimetableViewModel by next line:
timetableVM = ViewModelProviders.of(this).get(TimetableViewModel::class.java)
But on launch the app crashes with log:
Caused by: java.lang.RuntimeException: Cannot create an instance of class com.contedevel.timetable.model.TimetableViewModel
at android.arch.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:201)
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:134)
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:102)
at com.contedevel.timetable.activity.MainActivity.onCreate(MainActivity.kt:187)
at android.app.Activity.performCreate(Activity.java:6757)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2702)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2810) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6312) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762) 
Caused by: java.lang.NoSuchMethodException: <init> [class android.app.Application]
at java.lang.Class.getConstructor0(Class.java:2204)
at java.lang.Class.getConstructor(Class.java:1683)
at android.arch.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:199)
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:134) 
at android.arch.lifecycle.ViewModelProvider.get(ViewModelProvider.java:102) 
at com.contedevel.timetable.activity.MainActivity.onCreate(MainActivity.kt:187) 
at android.app.Activity.performCreate(Activity.java:6757) 
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119) 
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2702) 
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2810) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1528) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:154) 
at android.app.ActivityThread.main(ActivityThread.java:6312) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762)

Categories

Resources