android kotlin - Set CardView elevation

MainActivity.kt


package com.example.jetpack

import android.content.Context
import android.os.Bundle
import android.util.TypedValue
import androidx.appcompat.app.AppCompatActivity
import kotlinx.android.synthetic.main.activity_main.*


class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // set second card view elevation programmatically
        cardViewBottom.elevation = 4.dpToPixels(this)
        cardViewBottom.maxCardElevation = 6.dpToPixels(this)
    }
}


// extension function to convert dp to equivalent pixels
fun Int.dpToPixels(context: Context):Float = TypedValue.applyDimension(
    TypedValue.COMPLEX_UNIT_DIP,this.toFloat(),context.resources.displayMetrics
)

activity_main.xml


<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    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:id="@+id/constraintLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:background="#EDEAE0">

    <androidx.cardview.widget.CardView
        android:id="@+id/cardView"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        app:cardBackgroundColor="#7B68EE"
        app:cardCornerRadius="12dp"
        app:contentPadding="25dp"
        app:cardElevation="4dp"
        app:cardMaxElevation="6dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:gravity="center"
            android:padding="30dp"
            android:fontFamily="sans-serif-condensed-medium"
            android:text="CardView Elevation In XML"
            android:textSize="30sp" />

    </androidx.cardview.widget.CardView>

    <androidx.cardview.widget.CardView
        android:id="@+id/cardViewBottom"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginTop="32dp"
        android:layout_marginEnd="16dp"
        app:cardBackgroundColor="#E63E62"
        app:cardCornerRadius="12dp"
        app:contentPadding="25dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/cardView">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:padding="30dp"
            android:fontFamily="sans-serif-condensed-medium"
            android:text="CardView Elevation Programmatically"
            android:textSize="30sp" />

    </androidx.cardview.widget.CardView>
</androidx.constraintlayout.widget.ConstraintLayout>

build.gradle(app) [code to add]


dependencies {
    // card view
    implementation "androidx.cardview:cardview:1.0.0"
}