provider.get(QuizViewModel::class.java) ? doesn't work

[HothCoder]

val quizViewModel =provider.get(QuizViewModel::class.java)

This line of code doesn’t work on my computer

What should I do?

Android Studio says

Type parameter bound for T in operator fun <T : ViewModel!> get(p0: Class<T!>): T
is not satisfied: inferred type QuizViewModel! is not a subtype of ViewModel!

Any help?

My lines of code are

val provider:ViewModelProvider = ViewModelProviders.of(this)
val quizViewModel =provider.get(QuizViewModel::class.java)

[jpaone]

Solution previously discussed in

Solution to Deprecated method ViewModelProviders#of

The easy solution for this app is to change remove the ViewModelProviders usage. The ViewModel can be created using the default factory directly via the ViewModelProvider. private val quizViewModel: QuizViewModel by lazy { ViewModelProvider(this@QuizActivity).get(QuizViewModel::class.java) } However, this will not suffice for more complex ViewModels that depend upon other resources. For these situations, we will need to create our own Factory class. For this example, the factory would lik…

[HothCoder]

Hmm I have created the Factory File an put this text in

class QuizViewModelFactory : ViewModelProvider.Factory {
override fun <T : ViewModel?> create(modelClass: Class): T {
return modelClass.getConstructor().newInstance()
}
}

I also out this text in MainActivity

private val quizViewModel: QuizViewModel by lazy {
val factory = QuizViewModelFactory()
ViewModelProvider(this@QuizActivity, factory).get(QuizViewModel::class.java)
}

but it stopps at … .get again ???

Logcat says:

Type parameter bound for T in operator fun <T : ViewModel!> get(p0: Class<T!>): T
is not satisfied: inferred type QuizViewModel! is not a subtype of ViewModel!

Any help?

[jpaone]

Does the QuizViewModel class extend ViewModel?

// Listing 4.6 - QuizViewModel.kt
class QuizViewModel : ViewModel() {
  ...
}

[HothCoder]

Thank you - error vanished

[BaZZiL]

QuizViewModel.kt
class QuizViewModel:ViewModel(){
…
}

(MainActivity.kt)
class MainActivity:AppCompatActivity(){
private lateinit var quizViewModel :
…

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
…
quizViewModel = ViewModelProvider(this).get(QuizViewModel::class.java)

}

[Coolhabit]

Hello!

Has the problem with the mentioned solution, watch the screen.

GitHub - Coolhabit/GeoQuiz at deprecated