I have seen similar questions here, but none of them helps.

I have MainActivity and a few Fragments which works fine, but I want to set one fragment inside of another.

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val bottomNavigationView = findViewById<BottomNavigationView>(R.id.bottomMenu)
        val hostFragment = supportFragmentManager.findFragmentById(R.id.fragmentContainer) as NavHostFragment
        val navigationController = hostFragment.navController


        bottomNavigationView.setupWithNavController(navigationController)
        setupActionBarWithNavController(navigationController)
    }

    override fun onSupportNavigateUp(): Boolean {
        val navController = findNavController(R.id.fragmentContainer)
        return navController.navigateUp() || super.onSupportNavigateUp()
    }
}

Parent Fragment:

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        val view = inflater.inflate(R.layout.fragment_main, container, false)
        incomeButton = view.findViewById(R.id.addIncomeButton)
        expenseButton = view.findViewById(R.id.addExpenseButton)
        val childFragment: Fragment = ChartFragment()
        val transaction: FragmentTransaction = childFragmentManager.beginTransaction()
        transaction.replace(R.id.childFragment, childFragment).commit()
        return view
    }

Child Fragment:

override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        // Inflate the layout for this fragment
        return ComposeView(requireContext()).apply {
            setContent {
                Text(
                text = "here is another important code",
                fontSize = 28.sp
                )
            }
        }

The layouts for Activity:

<?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=".MainActivity">


    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@ id/bottomMenu"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:menu="@menu/bottom_menu" />

    <androidx.fragment.app.FragmentContainerView
        android:id="@ id/fragmentContainer"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="475dp"
        app:defaultNavHost="true"
        app:layout_constraintBottom_toTopOf="@ id/bottomMenu"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:navGraph="@navigation/nav_map" />
</androidx.constraintlayout.widget.ConstraintLayout>

The layouts for Fragment:

<?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=".fragments.MainFragment">

    <Button
        android:id="@ id/addIncomeButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="21dp"
        android:layout_marginBottom="21dp"
        android:backgroundTint="@color/primary"
        android:text="@string/addIncomeButton"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <Button
        android:id="@ id/addExpenseButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="21dp"
        android:layout_marginBottom="10dp"
        android:backgroundTint="@color/red"
        android:text="@string/addExpenseButton"
        app:layout_constraintBottom_toTopOf="@ id/addIncomeButton"
        app:layout_constraintEnd_toEndOf="parent" />

    <FrameLayout
        android:id="@ id/forChart"
        android:layout_width="match_parent"
        android:layout_height="350dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

The most of the same questions' solvations say to use childFragmentManager so do I but it doesn't work.

I get an error java.lang.IllegalArgumentException: No view found for id 0x7f08023f.

I guess I do not understand something, but I can't realize what.

Thank you!

CodePudding user response：

Seems that you're mixing the ids of the container for the transaction - that's also what the error says. You're trying to put the ChartFragment into a container with R.id.childFragment id:

transaction.replace(R.id.childFragment, childFragment).commit()

And from what I see in the MainFragment layout, the container id is R.id.forChart. Try changing it to this:

transaction.replace(R.id.forChart, childFragment).commit()