Question 125800 in Android Studio Question posted in
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Android Studio – Hilt – cannot be initialized ViewModelFactory in fragment

i’am using retrofit library to get info from internet api , then i put the data in the repository then get it in viewmodel which it will be instatiate by viewmodelfactory ;

so i’am trying to inject HitViewModelFactory by using Dagger-Hilt in Fragment but it show me an error when to inject it in the fragment

lateinit property hitViewModelFactory has not been initialized

i make an application class and anotate it with @HiltAndroidApp and give the name of application in manifest. and make anotate to activity that host this fragment but the problem not solved

@AndroidEntryPoint
class BaseActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {

 .......
}
}

i provide all dependencies that i need in the module class :

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

@Singleton
@Provides
fun provideHitPhotoApi() = Retrofit.Builder()
    .baseUrl(BASE_URL)
    .addConverterFactory(GsonConverterFactory.create())
    .build()
    .create(HitApi::class.java)

@Singleton
@Provides
fun provideHitRepository(hitApi: HitApi) = HitRepository(hitApi)

@Singleton
@Provides
fun provideHitViewModelFactory(hitRepository: HitRepository) : HitViewModelFactory = HitViewModelFactory(hitRepository)

 }

and try to inject ViewModelFactory in this fragment

@AndroidEntryPoint
class TripsFragment : Fragment() {

@Inject
lateinit var hitViewModelFactory: HitViewModelFactory

lateinit var hitViewModel: HitViewModel


override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    hitViewModel = ViewModelProvider(requireActivity(),hitViewModelFactory)[HitViewModel::class.java ]

}

dependency for hilt :

    Dagger - Hilt
    implementation "com.google.dagger:hilt-android:2.28-alpha"
    kapt "com.google.dagger:hilt-android-compiler:2.28-alpha"
    implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0- 
    alpha03"
    kapt "androidx.hilt:hilt-compiler:1.0.0"
Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    the problem solved when i change the dependency of Hilt to :

    implementation "com.google.dagger:hilt-android:2.38.1"
kapt "com.google.dagger:hilt-compiler:2.38.1"
implementation "androidx.hilt:hilt-lifecycle-viewmodel:1.0.0-alpha03"
kapt "androidx.hilt:hilt-compiler:1.0.0"

    and for these dependencies it should replace the InstallIn anotation for module class to SingletonComponent::class like

    @Module
@InstallIn(SingletonComponent::class)
object AppModule { ... }

  2. 0

    I also faced same issue earlier. Not sure why this fails but it seems code is correct.
    So I have done with different approach.
    I created view model like this below. And I inject HitApi directly in viewmodel constructor. Then just initialize like below. It takes care of creating viewmodel instance and hilt takes care of injection.No need of creating factory.

    ViewModel:

    @HiltViewModel
class HitViewModel @Inject constructor(
    var api: HitApi) : ViewModel() {
}

    Fragment:

     @AndroidEntryPoint
class TripsFragment : Fragment() {

    private val viewModel by viewModels<HitViewModel>() //No need of inject annotation.

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
}
}

    Make sure you have these dependancies.

    //For activity
implementation 'androidx.activity:activity-ktx:1.5.1'
//For fragment
implementation 'androidx.fragment:fragment-ktx:1.5.1'
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