ViewHolder not recognising textview on binding using Kotlin

Question

I am following a tutorial online due to this being my first time programming in kotlin, i just wanted to bind the text that i will get from a table in database to a ViewModel, i started with an example i saw online as a base:

in this code i am getting an error on the "itemView.userName.text = "test"", it does not recognise the 'userName' and i have no idea why.

With this Adapter

import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.example.timetally.R
import com.example.timetally.repository.entity.TaskType

class TaskTypeAdapter : RecyclerView.Adapter<TaskTypeAdapter.ViewHolder>() {

    private var taskTypeList = emptyList<TaskType>()

    class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        fun bind(taskType: TaskType) {
            itemView.userName.text = "test"
        }
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        val view = LayoutInflater.from(parent.context).inflate(R.layout.task_type_layout, parent, false)
        return ViewHolder(view)
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        holder.bind(taskTypeList[position])
    }

    override fun getItemCount(): Int = taskTypeList.size

    fun setData(userLtaskTypeListist: List<TaskType>) {
        this.taskTypeList = taskTypeList
        notifyDataSetChanged()
    }
}

And using this xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">
    <TextView
        android:id="@+id/userName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp" />
    <TextView
        android:id="@+id/userEmail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:textColor="@android:color/darker_gray" />
    <TextView
        android:id="@+id/userPhone"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:textColor="@android:color/darker_gray" />
    <TextView
        android:id="@+id/userWebsite"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="14sp"
        android:textColor="@android:color/darker_gray" />
</LinearLayout>

I have tried a simpler layouts with just the one textView, clean and rebuild the project but i can't make it work

Answer 1

This is not the way to use the view binding in android. First of all in your module's gradle you have to enable the view binding feature:

android {
    ...
    buildFeatures {
        viewBinding = true
    }
}

After that in your view holder you can create the binding instance and use it:

class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {

    private val binding = TaskTypeLayoutBinding.bind(itemView)

    fun bind(taskType: TaskType) {
        binding.userName.text = "test"
    }
}

When you enable the view binding feature, for all your layouts a binding class is generated automatically.