架构师David
5/11/2025
Here's my rewritten version:
Help! SearchView with RecyclerView driving me nuts! 😫
Hey fellow Android devs! 👋 Still working on my first Kotlin app (coming from VB.NET background) and I'm stuck on implementing search functionality for my contacts list. The RecyclerView loads contacts perfectly, but the search just won't behave!
I've watched like 10 different tutorials 🎥, copied code samples, but somehow my implementation keeps failing. The weird part is I don't even get the "No contacts found" toast when I search for non-existent names.
Here's what I've tried so far:
arrayList and mList (not sure which one I should actually use 😅)Main pain points:
Here's my current setup (simplified):
// MainActivity.kt searchView.setOnQueryTextListener(object : SearchView.OnQueryTextListener { override fun onQueryTextChange(newText: String?): Boolean { filterList(newText) // This gets called but nothing happens 😤 return true } // ... other override }) private fun filterList(query: String?) { if (query != null) { val filteredList = arrayList // Using the wrong list maybe? for (i in mList) { if (i.contname.contains(query, true)) { filteredList.add(i) // Is this the right approach? } } // This toast never shows even when it should if (filteredList.isEmpty()) Toast.makeText(this,"No contacts!", Toast.LENGTH_SHORT).show() else adapter.setFilteredList(arrayList) // Not updating properly } }
And my adapter:
fun setFilteredList(contactList: List<ContactModel>){ this.contactList = contactList as ArrayList<ContactModel> notifyDataSetChanged() // Pretty sure this should work? 🤔 }
I'm on a tight deadline to show this to some friends - any Kotlin gurus who can spot what I'm doing wrong? Would really appreciate some fresh eyes on this! 🙏
PS: Bonus question - should I be using mList or arrayList as my main contacts list? I think this might be part of my confusion...
#AndroidDev #KotlinHelp #RecyclerViewStruggles
程序员老刘
5/11/2025
Hey there! 👋 Oh man, I feel your pain with RecyclerView search struggles - been there, done that, got the t-shirt! 😅 I remember spending an entire weekend debugging a similar issue in my first Kotlin app (coming from Java background). Let's get this sorted for you!
First off, I can spot a few issues in your implementation. The main problem is that you're not properly clearing and rebuilding your filtered list. Here's how we can fix it:
private fun filterList(query: String?) { val filteredList = ArrayList<ContactModel>() // Create new list each time if (!query.isNullOrBlank()) { for (contact in mList) { // Use your original list (mList) as source if (contact.contname.contains(query, true)) { filteredList.add(contact) } } } else { filteredList.addAll(mList) // Show full list when query is empty } // Update UI based on results if (filteredList.isEmpty() && !query.isNullOrBlank()) { Toast.makeText(this, "No contacts found!", Toast.LENGTH_SHORT).show() } adapter.setFilteredList(filteredList) // Pass the properly filtered list }
Key fixes and explanations:
arrayList without clearing it first - this would just keep growing! We create a fresh list each time.mList should be your complete, unfiltered list (the "source of truth" as we say in Android dev 😉)Bonus answer to your PS question: Definitely use mList as your main contacts list! Here's a good pattern I've found works well:
private val mList = mutableListOf<ContactModel>() // Main list (never modified by filtering) private val displayedList = mutableListOf<ContactModel>() // What's shown in RecyclerView
Pro tip from my own mistakes: ⚠️ Always test these edge cases:
Also, consider using Filterable interface in your adapter for more complex filtering needs - but what you have should work fine for basic cases!
You're on the right track though! That notifyDataSetChanged() call is correct, and your adapter method looks good. Just needed to fix the filtering logic.
If you're still having trouble, try adding some Log.d statements to see what's actually in your lists at each step - this saved me countless times when I was learning!
You got this! 💪 Let me know if you need any clarification or run into other issues. Happy coding, and good luck with your app showcase! 🚀
#AndroidDev #Kotlin #RecyclerView #SearchFunctionality #ProgrammingHelp