👀 Views: 1 💬 Answers: 1 📅 Created: 2025-06-10

android fragments sharedpreferences lifecycle kotlin

I'm testing a new approach and Quick question that's been bugging me - I'm working with a crash in my Android app when navigating between fragments that share state through SharedPreferences... It occurs specifically when I rapidly switch between two fragments that both access a shared preference key. The behavior message I receive is: ``` java.lang.IllegalStateException: Fragment already added: FragmentA ``` I've implemented the following code in FragmentA and FragmentB to read and write to SharedPreferences: ```kotlin class FragmentA : Fragment() { private val sharedPreferences by lazy { requireActivity().getSharedPreferences("my_prefs", Context.MODE_PRIVATE) } override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) val editor = sharedPreferences.edit() editor.putString("key", "value from FragmentA") editor.apply() } } class FragmentB : Fragment() { private val sharedPreferences by lazy { requireActivity().getSharedPreferences("my_prefs", Context.MODE_PRIVATE) } override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) val value = sharedPreferences.getString("key", "default") // do something with value } } ``` I've tried wrapping the SharedPreferences access in try-catch blocks to see if it helps, but that doesn’t prevent the crash. I’m also using Android 14 with View Binding and the fragments are being added to a single Activity. I’m concerned if this is a threading scenario or something related to the fragment lifecycle that I am missing. Any advice on how to manage this scenario better or prevent the crash would be greatly appreciated. I'm working on a CLI tool that needs to handle this. The stack includes Kotlin and several other technologies.