ClassNotFoundException when using androidx.fragment.app.FragmentContainerView

Question

I\'m trying to transition from using a FrameLayout to using FragmentContainerView and from the tutorials I\'ve seen, it should be pretty easy. Howe

Answer 1

That's in androidx.fragment 1.2.0 or higher:

implementation "androidx.fragment:fragment:1.2.0"

Answer 2

Thanks to @Salam El-Banna and his link, I found that in case an application crashes in release build we should add in proguard-rules.pro (one or two lines, depending on android:name in <FragmentContainerView>:

#-------------------------------------------------
# JetPack Navigation
# This fixes: 
# Caused by: androidx.fragment.app.Fragment$InstantiationException: Unable to instantiate fragment androidx.navigation.fragment.NavHostFragment: make sure class name exists
# Caused by: androidx.fragment.app.Fragment$InstantiationException: Unable to instantiate fragment com.google.android.gms.maps.SupportMapFragment: make sure class name exists
#-------------------------------------------------

-keepnames class androidx.navigation.fragment.NavHostFragment
-keepnames class com.google.android.gms.maps.SupportMapFragment

You won't need implementation 'androidx.fragment:fragment:1.2.5' if your applicatin crashes in release build.