ViewBinding: Cannot access '<init>': it is private in 'ActivityMainBinding'

Question

I've tried multiple solutions and read some other answers talking about the visibility of the class, but I've no added any private or protected modifier.

The point is, that I'm just have a very simple ViewBinding configuration, but it's showing the following message when I try to run it.

e: /app/src/main/java/com/adalpari/example/view/MainActivity.kt: (16,40): Cannot access '': it is private in 'ActivityMainBinding'

e: /app/src/main/java/com/adalpari/example/view/MainActivity.kt: (16,60): No value passed for parameter 'rootView'

e: /app/src/main/java/com/adalpari/example/view/MainActivity.kt: (16,60): No value passed for parameter 'progressBar'

e: /app/src/main/java/com/adalpari/example/view/MainActivity.kt: (16,60): No value passed for parameter 'storiesView'

The code, as you can see is pretty simple..

MainActivity:

@AndroidEntryPoint
class MainActivity : AppCompatActivity() {

    val binding: ActivityMainBinding = ActivityMainBinding()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(binding.root)

        onObserve()
    }

    ...

}

xml file:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".view.MainActivity"
    >

    <com.adalpari.storiesview.view.StoriesView
        android:id="@+id/stories_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        />

    <ProgressBar
        android:id="@+id/progress_bar"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:visibility="invisible"
        app:layout_constraintBottom_toBottomOf="@+id/stories_view"
        app:layout_constraintEnd_toEndOf="@+id/stories_view"
        app:layout_constraintStart_toStartOf="@+id/stories_view"
        app:layout_constraintTop_toTopOf="@+id/stories_view"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

And finally the enabling of ViewBinding in app's gradle:

apply plugin: 'kotlin-kapt'

android {

    ...

    buildFeatures {
        viewBinding true
    }

    ...
}

Any help is very appreciated, thanks in advance!

Answer 1

You're not supposed to use the constructors of data binding classes (they're private, as your error message says). Use the method ActivityMainBinding.inflate() to create your binding object

binding = ActivityMainBinding.inflate(layoutInflater)
setContentView(binding.root)

This is shown in the official docs for ViewBinding