I'm trying to create a simple recyclerView in Kotlin with data that I get via Volley (which I have confirmed returns the correct data), I keep running to the error E/RecyclerView: No adapter attached; skipping layout
when in fact I have specified an adapter with the custom adapter class that I created:
class ImageAdapter(var c: Context, var list: ArrayList<Image>) : RecyclerView.Adapter<ImageAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder? {
val layoutInflater = LayoutInflater.from(parent.context)
return ViewHolder(layoutInflater.inflate(R.layout.image_cardview, parent, false))
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val imageUrl = list[position].url
val submitter = list[position].submitter
val color = list[position].color
holder.submitterTV.text = submitter
holder.card.setCardBackgroundColor(Color.parseColor(color))
}
override fun getItemCount() = list.size
class ViewHolder(itemView: View): RecyclerView.ViewHolder(itemView){
val card = itemView.card
val submitterTV = itemView.submitter
val imageView = itemView.image
}
}
This is my MainActivty class, where I make the actual call for the JSON and attempt to attach my adapter with my ArrayList that I have created:
class MainActivity : AppCompatActivity() {
val images = ArrayList<Image>()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
imageList.layoutManager = LinearLayoutManager(applicationContext)
request("https://api.unsplash.com/photos/curated/?client_id=API_KEY")
imageList.adapter = ImageAdapter(applicationContext, images)
}
private fun request(url: String) {
val queue = Volley.newRequestQueue(this)
val stringRequest = JsonArrayRequest(url, Response.Listener<JSONArray> { response ->
try {
for (i in 0..(response.length() - 1)) {
val image: Image = Image(response.getJSONObject(i).getJSONObject("urls").getString("full"), response.getJSONObject(i).getJSONObject("user").getString("username"), response.getJSONObject(i).getString("color"))
images.add(image)
}
imageList.adapter.notifyDataSetChanged()
} catch (e: JSONException) {
e.printStackTrace()
}
}, Response.ErrorListener { })
queue.add(stringRequest)
}
}
I have created a custom data class Image
which stores three fields: the imageUrl, submitter and color, all of which are derived from the JSON. I thought that calling notifyDataSetChanged()
on my adapter after the request was completed would allow the recyclerView to get updated and show the items, but nothing at all shows up on the screen. Does anyone have any idea as to where I messed up?
Go to app > java > package name > right-click > New > Kotlin class/file and name that file as CustomAdapter and then click on OK. After this add the code provided below. Comments are added inside the code to understand the code in more detail.
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project. Step 2 − Open build. gradle and add Recycler view & Card view library dependencies. Step 3 − Add the following code to res/layout/activity_main.
You can download the source code from here(Recyclerview In Kotlin Android)
MainActivity.kt:
package com.deepshikha.recyclerviewkotlin
import android.app.Activity
import android.os.Bundle
import android.support.v7.widget.LinearLayoutManager
import android.view.Window
import android.view.WindowManager
import android.widget.LinearLayout
import kotlinx.android.synthetic.main.activity_main.*
import net.simplifiedcoding.recyclerviewexample.CustomAdapter
class MainActivity : Activity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
requestWindowFeature(Window.FEATURE_NO_TITLE)
window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN)
setContentView(R.layout.activity_main)
val users = ArrayList<Model_Details>()
users.add(Model_Details("Kaju katli", "Kaju katli, also known as kaju Katari or kaju barfi, is an Indian dessert similar to a barfi.",R.drawable.kaju))
users.add(Model_Details("Doughnut", "The doughnut is popular in many countries and prepared in various forms as a sweet snack that can be homemade or purchased in bakeries, supermarkets, food stalls, and franchised specialty outlets",R.drawable.donuts))
users.add(Model_Details("Panna cotta", "Panna cotta is an Italian dessert of sweetened cream thickened with gelatin and molded. The cream may be aromatized with rum, coffee, vanilla, or other flavorings.",R.drawable.panna_cotta))
users.add(Model_Details("Rose Cookies", "Rose cooky is a famous South Indian snack made during festivals",R.drawable.rosecookies))
users.add(Model_Details("Belgian waffle", "In North America, Belgian waffles are a variety of waffle with a lighter batter, larger squares, and deeper pockets than ordinary American waffles",R.drawable.belgianwaffle))
val obj_adapter = CustomAdapter(users)
recyclerView.layoutManager = LinearLayoutManager(this, LinearLayout.VERTICAL, false)
recyclerView.adapter = obj_adapter
}
}
CustomAdapter.kt:
package net.simplifiedcoding.recyclerviewexample
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import com.deepshikha.recyclerviewkotlin.Model_Details
import com.deepshikha.recyclerviewkotlin.R
import kotlinx.android.synthetic.main.adapter_details.view.*
class CustomAdapter(val userList: ArrayList<Model_Details>) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
//this method is returning the view for each item in the list
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapter.ViewHolder {
val v = LayoutInflater.from(parent.context).inflate(R.layout.adapter_details, parent, false)
return ViewHolder(v)
}
//this method is binding the data on the list
override fun onBindViewHolder(holder: CustomAdapter.ViewHolder, position: Int) {
holder.bindItems(userList[position])
}
//this method is giving the size of the list
override fun getItemCount(): Int {
return userList.size
}
//the class is hodling the list view
class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bindItems(user: Model_Details) {
itemView.tv_name.text=user.name
itemView.tv_des.text=user.des
itemView.iv_name.setImageResource(user.image)
}
}
}
Thanks!
Look at following example, I think you this can give you an idea.
You can get the example from here : https://github.com/Siddharha/RecyclerviewTest_Kotlin
Main Activity
class MainActivity : AppCompatActivity() {
private var myAdapter: MyAdapter? = null
private var arrayList: ArrayList<MyItem>? = null
private var layoutManager: RecyclerView.LayoutManager? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
initialize()
setupList()
loaddata()
}
private fun loaddata() {
for (i in 0..9) {
val myItem = MyItem()
myItem.name = "Sid_" + i
myItem.number = "098899876" + i
arrayList!!.add(myItem)
}
myAdapter!!.notifyDataSetChanged()
}
private fun setupList() {
rlItems!!.layoutManager = layoutManager
rlItems!!.adapter = myAdapter
}
private fun initialize() {
arrayList = ArrayList<MyItem>()
layoutManager = LinearLayoutManager(this, LinearLayout.VERTICAL, false)
myAdapter = MyAdapter(arrayList!!, this, R.layout.item_cell)
}
}
Adapter Class
internal class MyAdapter(private val arrayList: ArrayList<MyItem>,
private val context: Context,
private val layout: Int) : RecyclerView.Adapter<MyAdapter.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyAdapter.ViewHolder {
val v = LayoutInflater.from(parent.context).inflate(layout, parent, false)
return ViewHolder(v)
}
override fun onBindViewHolder(holder: MyAdapter.ViewHolder, position: Int) {
holder.bindItems(arrayList[position])
}
override fun getItemCount(): Int {
return arrayList.size
}
internal inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
fun bindItems(items: MyItem) {
itemView.tvName.text = items.name
itemView.tvNumber.text = items.number
}
}
}
Item Class
internal class MyItem {
var name: String? = null
var number: String? = null
}
try to use Delegate Adapters below is reference link.
Ref Link : https://android.jlelse.eu/keddit-part-4-recyclerview-delegate-adapters-data-classes-with-kotlin-9248f44327f7
I have my RecyclerView Adapter which is as follows,
internal class OptionsAdapter : RecyclerView.Adapter<OptionsAdapter.ViewHolder>() {
private val mOptionList = ArrayList<Option>()
private var mOnItemClickListener: OnItemClickListener<Option>? = null
var data: List<Option>
get() = mOptionList
set(list) {
mOptionList.clear()
mOptionList.addAll(list)
notifyDataSetChanged()
}
fun setOnItemClickListener(listener: OnItemClickListener<Option>) {
mOnItemClickListener = listener
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
return ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.layout_text, parent, false))
}
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val option = getItem(position)
holder.textViewOption.setText(option.text)
holder.textViewDescription.setText(option.subText)
}
private fun getItem(index: Int): Option {
return mOptionList[index]
}
override fun getItemCount(): Int {
return mOptionList.size
}
internal inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
var textViewOption: TextView
var textViewDescription: TextView
var imageViewOptionIcon: ImageView
init {
textViewOption = itemView.findViewById<TextView>(R.id.textview_option)
imageViewOptionIcon = itemView.findViewById<ImageView>(R.id.imageview_option_icon)
textViewDescription = itemView.findViewById<TextView>(R.id.textview_description)
itemView.setOnClickListener {
if (mOnItemClickListener != null) {
mOnItemClickListener!!.onItemClick(getItem(adapterPosition))
}
}
}
}
}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With