I've tried to make a RecyclerView with an Adapter but I cannot see the layout? - kotlin

Question

I've tried to build a recyclerview with an adapter class and cardview layout however even though the code runs I cannot see the list with cardview (I just get a blank recyclerview)?
SpeakerAdapter.kt
class SpeakerAdapter (val speakers: ArrayList<String>): RecyclerView.Adapter<SpeakerAdapter.ViewHolder>() {
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
val speakerName: TextView = itemView.findViewById(R.id.name)
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.speakerName.text = speakers[position]
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val View = LayoutInflater.from(parent.context).inflate(R.layout.speaker_list, parent, false)
return ViewHolder(View)
}
override fun getItemCount() = speakers.size
}
Speaker.kt
class Speaker : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?, persistentState: PersistableBundle?) {
super.onCreate(savedInstanceState, persistentState)
setContentView(R.layout.activity_speaker)
val speakers : ArrayList<String> = ArrayList()
for (i in 1..100){
speakers.add("Speaker 1 #$i")
recyclerView_speaker.layoutManager = LinearLayoutManager(this)
recyclerView_speaker.adapter = SpeakerAdapter(speakers)
}
}}

Answer 1

It's a bit hard to debug without the xml. But here goes nothing:
I think it'd be worth a shot modifying your view holder class. The reference for the text view is being set when you init the view holder and the layout may not be inflated yet. Try finding the reference when you bind the data to the view to avoid this issue.
Try this:
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bind(name: String?) {
itemView. name.text = name
}
}
and then modify your adapter to call this method
class SpeakerAdapter (val speakers: ArrayList<String>): RecyclerView.Adapter<SpeakerAdapter.ViewHolder>() {
...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.bind(speakers[position])
}
}
PS.: it'd be a good idea to call your view holder something else. ViewHolder is a name that is already used by the android SDK. Ex.: SpeakerViewholder