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androidkotlinandroid-jetpackdagger-hilt

Cannot create instance of viewmodel after using Hilt in Android


Here is my AllFilesListViewModel class.

class AllFilesListViewModel @ViewModelInject constructor(
    private val pdfItemRepository: PdfItemRepository):ViewModel() {

}

Here is PdfItemRepository class.

@Singleton
class PdfItemRepository @Inject constructor(private val pdfItemDao: PdfItemDao){

}

For pdfItemDao. I created a module named DatabaseModule. Below is the code -

@Module
@InstallIn(ApplicationComponent::class)
object DatabaseModule {

    @Provides
    fun provideDatabase(@ApplicationContext context: Context):AppDatabase{
        return AppDatabase.getDataBase(context)
    }

    @Provides
    fun providePdfItemDao(database:AppDatabase):PdfItemDao{
        return database.pdfItemDao()
    }
}

Here is the fragment class AllFilesFragment.kt where I am using viewModel.

@AndroidEntryPoint
class AllFilesFragment:Fragment(){

    private lateinit var binding:AllFilesFragmentBinding
    private val viewModel by viewModels<AllFilesListViewModel>()


    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        binding = AllFilesFragmentBinding.inflate(inflater,container,false)
        context?: return binding.root
        initThings()
        subscribeUi()
        return binding.root
    }
}

Here is logcat file.

06-19 19:22:20.203 23753-23753/com.emptysheet.pdfreader_autoscroll E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.emptysheet.pdfreader_autoscroll, PID: 23753
    java.lang.RuntimeException: Cannot create an instance of class com.emptysheet.pdfreader_autoscroll.homeScreen.viewModel.AllFilesListViewModel
        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:106)
        at androidx.hilt.lifecycle.HiltViewModelFactory.create(HiltViewModelFactory.java:69)
        at androidx.lifecycle.AbstractSavedStateViewModelFactory.create(AbstractSavedStateViewModelFactory.java:69)
        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.emptysheet.pdfreader_autoscroll.homeScreen.AllFilesFragment.getViewModel(AllFilesFragment.kt)
        at com.emptysheet.pdfreader_autoscroll.homeScreen.AllFilesFragment.subscribeUi(AllFilesFragment.kt:72)
        at com.emptysheet.pdfreader_autoscroll.homeScreen.AllFilesFragment.onCreateView(AllFilesFragment.kt:64)
        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.moveToState(FragmentManager.java:1356)
        at androidx.fragment.app.FragmentManager.moveFragmentToExpectedState(FragmentManager.java:1434)
        at androidx.fragment.app.BackStackRecord.executeOps(BackStackRecord.java:442)
        at androidx.fragment.app.FragmentManager.executeOps(FragmentManager.java:2169)
        at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:1992)
        at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:1947)
        at androidx.fragment.app.FragmentManager.execSingleAction(FragmentManager.java:1818)
        at androidx.fragment.app.BackStackRecord.commitNow(BackStackRecord.java:297)
        at androidx.viewpager2.adapter.FragmentStateAdapter.placeFragmentInViewHolder(FragmentStateAdapter.java:341)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:276)
        at androidx.viewpager2.adapter.FragmentStateAdapter.onViewAttachedToWindow(FragmentStateAdapter.java:67)
        at androidx.recyclerview.widget.RecyclerView.dispatchChildAttached(RecyclerView.java:7556)
        at androidx.recyclerview.widget.RecyclerView$5.addView(RecyclerView.java:860)
        at androidx.recyclerview.widget.ChildHelper.addView(ChildHelper.java:107)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addViewInt(RecyclerView.java:8601)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8559)
        at androidx.recyclerview.widget.RecyclerView$LayoutManager.addView(RecyclerView.java:8547)
        at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1641)
        at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)
        at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:665)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
        at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
        at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4404)
        at android.view.View.layout(View.java:15689)
        at android.view.ViewGroup.layout(ViewGroup.java:5048)
        at androidx.viewpager2.widget.ViewPager2.onLayout(ViewPager2.java:527)
        at android.view.View.layout(View.java:15689)
        at android.view.ViewGroup.layout(ViewGroup.java:5048)
        at com.google.android.material.appbar.HeaderScrollingViewBehavior.layoutChild(HeaderScrollingViewBehavior.java:148)
        at com.google.android.material.appbar.V

Solution

  • This got solved after I used kapt 'androidx.hilt:hilt-compiler:1.0.0-alpha01' in app's build.gradle. I had already added kapt "com.google.dagger:hilt-android-compiler:2.28-alpha". I still didn't understand the difference between two BTW. If anyone knows. Please explain it to me.