Calling a button from MainActivity file

Issue

By any chance anyone knows why I may be getting an error in my MainActivity file when I try to call a button; I already gave it an id in the activity_main file, can anyone help me shed some light on this please, id in activity_main is "btnDatePicker"

MainActivity file

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)
        
        btnDatePicker.setOnClickListener{
            
        }

    }

}

activity_main file

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:background="@color/backgroundColor"
    tools:context=".MainActivity"
    android:padding="16dp">   
 
    <Button
        android:id="@+id/btnDatePicker"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textColor="#929292"
        android:text="@string/select_date"
        android:layout_marginTop="15dp"
        android:textStyle="bold"
        android:textSize="20sp"/>   

</LinearLayout>

Solution

First thing you need to do is,

Integrating Kotlin Android Extensions in your code

Steps1: Add this to your app.gradle

plugins {
    id 'com.android.application'
    id 'kotlin-android'
    id 'kotlin-android-extensions'
    id 'kotlin-kapt'
}

Step2: Add this the import session of your activity

import kotlinx.android.synthetic.main.activity_main.*

Finished. Everything will go well. Please do add your error in the Question to understand more.

Answered By - Varun Chandran