Barcode Scanning in Android using Kotlin?

This example demonstrates how to implement bar code scanning in Kotlin.
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 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools"
   android:id="@+id/relativeLayout"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   android:padding="4dp"
   tools:context=".MainActivity">
   <TextView
      android:id="@+id/textView"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerHorizontal="true"
      android:layout_marginTop="50dp"
      android:padding="8dp"
      android:text="Tutorials Point"
      android:textColor="@android:color/holo_green_dark"
      android:textSize="48sp"
      android:textStyle="bold" />
   <TextView
      android:id="@+id/txtContent"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_below="@id/button"
      android:layout_centerInParent="true"
      android:layout_marginBottom="10dp"
      android:text=" code reader"
      android:textSize="16sp"
      android:textStyle="bold" />
   <Button
      android:id="@+id/button"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:layout_marginTop="50dp"
      android:text="Process" />
</RelativeLayout>
Step 3 − Add the following the dependency to build.gradle (Module:app)
implementation 'com.google.zxing:core:3.3.3'
implementation 'com.journeyapps:zxing-android-embedded:3.2.0@aar'
Step 4 − Add the following code to src/MainActivity.kt
import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.widget.Button
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.google.zxing.integration.android.IntentIntegrator
class MainActivity : AppCompatActivity() {
   lateinit var btnBarcode: Button
   lateinit var textView: TextView
   override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
      title = "KotlinApp"
      btnBarcode = findViewById(R.id.button)
      textView = findViewById(R.id.txtContent)
      btnBarcode.setOnClickListener {
         val intentIntegrator = IntentIntegrator(this@MainActivity)
         intentIntegrator.setBeepEnabled(false)
         intentIntegrator.setCameraId(0)
         intentIntegrator.setPrompt("SCAN")
         intentIntegrator.setBarcodeImageEnabled(false)
         intentIntegrator.initiateScan()
      }
   }
   override fun onActivityResult(
      requestCode: Int,
      resultCode: Int,
      data: Intent?
   ) {
      val result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data)
      if (result != null) {
         if (result.contents == null) {
            Toast.makeText(this, "cancelled", Toast.LENGTH_SHORT).show()
         } else {
            Log.d("MainActivity", "Scanned")
            Toast.makeText(this, "Scanned -> " + result.contents, Toast.LENGTH_SHORT)
            .show()
            textView.text = String.format("Scanned Result: %s", result)
         }
      } else {
         super.onActivityResult(requestCode, resultCode, data)
      }
   }
}
Step 5 − Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="app.com.q12">
<uses-feature android:name="android.hardware.camera.autoFocus" />
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click the Run icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen