Please help me, I can't implement onBindViewHolder in my RecyclerView in Kotlin. I want to make an adapter for my data cards using Reyclerview in Kotlin language android studio. But when I implement onBindViewHolder my code throws an error. Please help.
package com.brid.azis.vipgame.test.Adapter
import android.content.Context
import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.ViewGroup
import android.view.View
import android.widget.TextView
import com.brid.azis.vipgame.R
import com.brid.azis.vipgame.test.DataModel.DataCard
class MissionViewAdapter(private val context: Context, private val cards:List<DataCard>):
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int) =
CardViewHolder(LayoutInflater.from(context).inflate(R.layout.item_mission,parent,false))
override fun getItemCount(): Int = cards.size
override fun onBindViewHolder(holder: CardViewHolder, position: Int) {
holder.bindCards(cards[position])
}
class CardViewHolder(view:View):RecyclerView.ViewHolder(view) {
val judul = view.findViewById<TextView>(R.id.tv_judulkartu)
val petunjuk = view.findViewById<TextView>(R.id.tv_petunjukkartu)
val tanggal = view.findViewById<TextView>(R.id.tv_tanggalmasukkartu)
fun bindCards(cards:DataCard) {
judul.text = cards.judul
petunjuk.text = cards.petunjuk
tanggal.text = cards.tanggal
}
}
}
This is the error:
Just change this line
class MissionViewAdapter(private val context: Context, private val cards:List<DataCard>):
RecyclerView.Adapter<RecyclerView.ViewHolder>() {
to
class MissionViewAdapter(private val context: Context, private val cards:List<DataCard>):
RecyclerView.Adapter<MissionViewAdapter.CardViewHolder>() {
Actually, you are using the main ViewHolder class of RecyclerView. That's why your parameters are wrong of bindViewHolder method and you are getting that error. In this case, your onBindViewHolder method should look like this:
override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
Related
I need to remove child from Firebase after onClick from RecyclerView Adapter.
I have something like this:
Firebase database is
recyclerview is
My biggest problem is not sure how to get the "key" of the child node from the recyclerview.
I have been stuck on this supposedly simple thing for about 3 days so hopefully any help is appreciated.
package com.cpg12.findingfresh.adapters
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.cpg12.findingfresh.R
import com.cpg12.findingfresh.database.ShoppingList
import com.google.firebase.database.FirebaseDatabase
class ShoppingListAdapter : RecyclerView.Adapter<ShoppingListAdapter.ShoppingListViewHolder>() {
private val shoppingList = ArrayList<ShoppingList>()
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ShoppingListViewHolder {
val itemView = LayoutInflater.from(parent.context)
.inflate(R.layout.shopping_list_item, parent, false)
/** References the node to which market data is stored**/
val databaseReference = FirebaseDatabase.getInstance().getReference("Users")
return ShoppingListViewHolder(itemView)
}
override fun onBindViewHolder(holder: ShoppingListAdapter.ShoppingListViewHolder, position: Int) {
val currentItem = shoppingList[position]
holder.sListItem.text = currentItem.shoppingItem
}
override fun getItemCount(): Int {
return shoppingList.size
}
fun updateShoppinglist(shoppingList: List<ShoppingList>){
this.shoppingList.clear()
this.shoppingList.addAll(shoppingList)
notifyDataSetChanged()
}
class ShoppingListViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), View.OnClickListener {
val sListItem : TextView = itemView.findViewById(R.id.ShoppingItemTV)
override fun onClick(v: View?) {
databaseReference.child(marketName).setValue(markets).child(key).setValue("")
}
}
}
I am not able to figure out how to change the value of alpha when clicked on the item of the RecyclerView . I want to change the value of alpha from 1 to 0.5 .
Below is the Adapter Class for the same .
package GiftClass
import LeaderboardClass.LeaderboardAdapter
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.gearsrun.www.R
import kotlinx.android.synthetic.main.item_gift.view.*
class GiftAdapter(private val giftList: List<Gift>) : RecyclerView.Adapter<GiftAdapter.GiftViewHolder>() {
private lateinit var mlistener : onItemClickListener
interface onItemClickListener{
fun onItemClick(position: Int)
}
fun setOnItemClickListener(listener: onItemClickListener){
mlistener = listener
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): GiftViewHolder {
val itemView = LayoutInflater.from(parent.context).inflate(R.layout.item_gift,parent,false)
return GiftViewHolder(itemView,mlistener)
}
override fun onBindViewHolder(holder: GiftViewHolder, position: Int) {
val currentItem = giftList[position]
holder.item_img.setImageResource(currentItem.imageResource)
holder.item_price.text = currentItem.price
holder.item_soldNum.text = currentItem.sold_num
holder.item_medal.text = currentItem.medal_num
}
override fun getItemCount() = giftList.size
class GiftViewHolder(itemView: View,listener:onItemClickListener) : RecyclerView.ViewHolder(itemView){
val item_img:ImageView = itemView.item_img
val item_price : TextView = itemView.price
val item_soldNum : TextView = itemView.sold_num
val item_medal : TextView = itemView.medal_num
init {
itemView.setOnClickListener {
listener.onItemClick(absoluteAdapterPosition)
itemView.alpha = 0.5f
}
}
}
}
Added References / Suggestion are appreciated
In the onClickListener , you can get the property itemView.alpha and adjust the alpha values as per your needs
I'm developing an android app in kotlin, and I want to have a button in every recyclerView element, which will launch an intent - the same in whole recycle view, but with different parameters(for now it's just position for testing, in final form that will be some value from database).
I write the following code for that(inside my adapter class):
override fun onBindViewHolder(holder: ProjectViewHolder, position: Int) {
val Edit: Button = holder.view.EditButton
Edit.setOnClickListener()
{
var projekt: Intent = Intent(applicationContext, Project::class.java)
projekt.putExtra("id", position)
startActivity(projekt)
}
But I get "unresolved refference" error for applicationContext. I used buttons with intent like that before and that worked perfectly fine, though this is the first time I'm trying to do it inside recyclerView element.
How to make it work? Maybe I just take the wrong approach and it should be done in different way?
Edit: Complete adapter class file:
package com.example.legoapp127260
import android.content.Intent
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.Button
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import kotlinx.android.synthetic.main.project_item_layout.view.*
class ProjectAdapter : RecyclerView.Adapter<ProjectViewHolder>()
{
override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ProjectViewHolder {
val layoutInflater = LayoutInflater.from(viewGroup.context)
val projectRow = layoutInflater.inflate(R.layout.project_item_layout, viewGroup, false)
return ProjectViewHolder(projectRow)
}
override fun getItemCount(): Int {
return 2;
}
override fun onBindViewHolder(holder: ProjectViewHolder, position: Int) {
val projectName: TextView = holder.view.projectName
val projectNames: Array<String> = arrayOf("Set 1", "Set 2")
val Edit: Button = holder.view.EditButton
projectName.setText(projectNames[position])
Edit.setOnClickListener()
{
var projekt: Intent = Intent(Edit.context, Project::class.java)
projekt.putExtra("id", position)
Edit.context.startActivity(projekt)
}
}
}
class ProjectViewHolder(val view: View) : RecyclerView.ViewHolder(view)
{
}
You can get context from your button:
var projekt: Intent = Intent(Edit.context, Project::class.java)
projekt.putExtra("id", position)
Edit.context.startActivity(projekt)
I am new on kotlin .Getting error on click listner on line holder.initilise(chapterlist.get(position),clickListener)
Error shows on word clickListener . Kindly help me to resolve my issue. i want to click on one view and transfer on another recyclerView. These list shows chapters i want to go on topics list and every chapter has its own topics.holder.initilise(chapterlist.get(position),clickListener) is commented in the code and it just shows the list which i extract from backend
Code :
import android.content.Context
import android.view.Display
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
class CustomeAdapter(val ctx: Context, var clickListener: Int, var chapterlist:ArrayList<Model>) : RecyclerView.Adapter<ViewHolder>() {
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
val user : Model = chapterlist[position]
holder?.textViewName?.text=user.name
holder?.textViewChapter?.text=user.desc
// holder.initilise(chapterlist.get(position),clickListener) //(getting error on clickListener)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
val v = LayoutInflater.from(parent?.context).inflate(R.layout.row,parent,false)
return ViewHolder(v)
}
override fun getItemCount(): Int {
return chapterlist.size
}
}
class ViewHolder(itemView: View) :RecyclerView.ViewHolder(itemView){
val textViewName = itemView.findViewById(R.id.textView) as TextView
val textViewChapter = itemView.findViewById(R.id.textView2) as TextView
fun initilise(list: Model, action:OnChapterClick){
textViewName.text=list.name
textViewChapter.text=list.desc
itemView.setOnClickListener{
action.onItemClick(list,adapterPosition)
}
}
}
interface OnChapterClick {
fun onItemClick(list: Model,position: Int )
}
Follow below steps:
Step - 1: You have to implements OnChapterClick in your MainActivity2
class MainActivity2: AppCompatActivity, OnChapterClick {
....
override fun onItemClick(list: Model, position: Int ) {
//Implement your logic here
}
}
Step - 2: Change your CustomeAdapter's constructor to accept OnChapterClick instead of int
class CustomeAdapter(val ctx: Context, var clickListener: OnChapterClick, var chapterlist:ArrayList<Model>) : RecyclerView.Adapter<ViewHolder>() {
....
}
Step - 3: Initialize the adapter with this instead of R.layout.row like below:
val adapter = CustomeAdapter(applicationContext, this#MainActivity2, chapterlist)
Your clickListener is defined to be an Int:
var clickListener: Int
That's probably wrong, since integers can't listen to clicks. It should probably be:
var clickListener: OnChapterClick
I have heard it is good practice to implement the onClickListener inside of the ViewHolder. However, I am not sure how to access the item that is associated with the ViewHolder inside of the onClickListener.
For example:
import android.content.Context
import androidx.recyclerview.widget.RecyclerView
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import kotlinx.android.synthetic.main.post.view.*
import rstudio.vedantroy.swarm.MainActivity.Companion.TAG
class PostAdapter(private val items : List<Post>, private val contex: Context) : RecyclerView.Adapter<MyViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
return MyViewHolder(LayoutInflater.from(contex).inflate(R.layout.post, parent, false))
}
override fun getItemCount(): Int {
return items.size
}
override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
holder.bodyContent.text = items[position].content
}
}
class MyViewHolder(view: View): RecyclerView.ViewHolder(view), View.OnClickListener {
override fun onClick(v: View?) {
TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
}
val bodyContent : TextView = view.bodyContent
}
How do I access items, and how do I find out the current index of the ViewHolder?
I looked at this example: Recyclerview(Getting item on Recyclerview), but there was no explanation of where mDataSource comes from.
Personally what I find is a good solution is to set the OnClickListener within the onBindViewHolder.
For example,
// ... adapter class ...
override fun onBindViewHolder(holder: ViewHolder, position: Int) {
holder.view.apply {
bodyContent.text = items[position].content
setOnClickListener {
// TODO Handle onClick
}
}
}
class ViewHolder(val view: View) : RecyclerView.ViewHolder(view)
Also I find just storing the view within the ViewHolder makes it very easy to access any elements within the layout.
I managed to implement this behavior by moving the location of PostViewHolder. However, I am not sure if inner class will break something.
package rstudio.vedantroy.swarm
import android.content.Context
import androidx.recyclerview.widget.RecyclerView
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.cardview.widget.CardView
import kotlinx.android.synthetic.main.post.view.*
import rstudio.vedantroy.swarm.MainActivity.Companion.TAG
class PostAdapter(private val items : List<Post>, private val contex: Context) : RecyclerView.Adapter<PostAdapter.PostViewHolder>() {
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): PostViewHolder {
return PostViewHolder(LayoutInflater.from(contex).inflate(R.layout.post, parent, false))
}
override fun getItemCount() = items.size
override fun onBindViewHolder(holder: PostViewHolder, position: Int) {
holder.bodyContent.text = items[position].content
}
inner class PostViewHolder(view: View): RecyclerView.ViewHolder(view) {
val bodyContent : TextView = view.bodyContent
init {
view.apply {
setOnClickListener {
isClickable = false
Log.d(TAG, "Clicked!")
}
}
}
}
}