👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-22

android recyclerview theming kotlin

I'm converting an old project and I'm working on a project and hit a roadblock. I'm facing an issue where changes to the app's theme (specifically, switching between light and dark mode) are not reflecting in the items of a RecyclerView. I've set up a simple RecyclerView with a custom adapter, and while the activity's theme changes correctly, the items remain in the original theme until they are redrawn. Here's a snippet of my code where I handle the theme change: ```kotlin class MainActivity : AppCompatActivity() { private lateinit var recyclerView: RecyclerView private lateinit var adapter: MyAdapter override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) recyclerView = findViewById(R.id.recyclerView) adapter = MyAdapter(getData()) recyclerView.adapter = adapter } fun onThemeChange() { AppCompatDelegate.setDefaultNightMode(AppCompatDelegate.MODE_NIGHT_YES) adapter.notifyDataSetChanged() // This doesn’t seem to work } } ``` In my `MyAdapter` class, I am inflating the views as follows: ```kotlin class MyAdapter(private val data: List<MyData>) : RecyclerView.Adapter<MyViewHolder>() { override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder { val view = LayoutInflater.from(parent.context).inflate(R.layout.item_view, parent, false) return MyViewHolder(view) } override fun onBindViewHolder(holder: MyViewHolder, position: Int) { holder.bind(data[position]) } override fun getItemCount(): Int = data.size } ``` The `item_view.xml` has background colors defined for both light and dark modes, but they are not updating automatically. I’ve tried calling `adapter.notifyDataSetChanged()` after changing the theme, but it doesn’t seem to trigger a rebind of the views' styles. Additionally, I've confirmed that the theme changes do take effect in other UI components. Is there a recommended approach to ensure that RecyclerView items reflect dynamic theme changes immediately? I've also looked into overriding `onViewAttachedToWindow()` to force a redraw but that feels hacky. Any insights or best practices would be greatly appreciated! This is part of a larger web app I'm building. What's the best practice here? My team is using Kotlin for this microservice.