bottom navigation view doesnt shows fargment unless double click

Issue

i fixed the previous error but now this here. fragment isnt visible if i dont click bottom navigation two times. my code:

activity_main.xml

<androidx.fragment.app.FragmentContainerView
    android:id="@+id/FragmentContainerView"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    app:layout_constraintBottom_toTopOf="@+id/bottom_navigation"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintHorizontal_bias="0.0"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent" />

<com.google.android.material.bottomnavigation.BottomNavigationView
    android:id="@+id/bottom_navigation"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:menu="@menu/bottom_navigation_menu" />

MainActivity.kt

binding.bottomNavigation.setOnItemReselectedListener { item ->
        when(item.itemId) {
            R.id.home -> {
                replaceFragment(HomeFragment())
            }
            R.id.favs -> {
                replaceFragment(FavsFragment())
            }
        }
    }
}

private fun replaceFragment(fragment: Fragment) {
    val fragmentManager = supportFragmentManager
    val fragmentTransaction = fragmentManager.beginTransaction()

    fragmentTransaction.replace(R.id.FragmentContainerView, fragment)
    fragmentTransaction.commit()
}

Solution

Instead of setOnItemReselectedListener you should use setOnItemSelectedListener to avoid "double-clicking".

But you still have to add initial fragment to FragmentContainerView. For example, in onCreate() you can call your replaceFragment() with the fragment that you need to be shown at first.

Answered By - Stepan Kulagin