How Do You Integrate a QR Code With an Android App?

Integrating a QR code with an Android app can open up a world of possibilities for enhancing user experiences and streamlining processes. QR codes, or Quick Response codes, are two-dimensional barcodes that can be scanned using a smartphone’s camera.

They can contain various types of information, such as URLs, text, or contact information. In this tutorial, we will explore how to integrate a QR code with an Android app.

Step 1: Adding the Required Dependencies

To begin with, we need to add the necessary dependencies to our Android project. Open your project’s build.gradle file and add the following lines of code inside the dependencies block:

implementation ‘com.google.zxing:core:3.4.1’
implementation ‘com.journeyapps:zxing-android-embedded:3.0’

These dependencies will enable us to generate and scan QR codes within our Android app.

Step 2: Creating a QR Code Generator

Now that we have added the required dependencies, let’s start by creating a QR code generator in our Android application. Create a new Java class called QRCodeGenerator.java. Inside this class, add the following code:

import android.graphics.Bitmap;
import android.util.Log;

import com.zxing.BarcodeFormat;
import com.EncodeHintType;
import com.WriterException;
import com.common.BitMatrix;
import com.journeyapps.barcodescanner.BarcodeEncoder;

import java.HashMap;
import java.Map;

public class QRCodeGenerator {

    public Bitmap generateQRCode(String data) {
        Map hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");

        try {
            BitMatrix bitMatrix = new BarcodeEncoder().encodeBitmap(data, BarcodeFormat.QR_CODE, 500, 500, hints);
            return Bitmap.createBitmap(bitMatrix.getWidth(), bitMatrix.getHeight(), Bitmap.Config.RGB_565);
        } catch (WriterException e) {
            Log.e("QRCodeGenerator", "Error generating QR code: " + e.getMessage());
        }

        return null;
    }
}

This code uses the ZXing library to generate a QR code bitmap from the given data. The generateQRCode method takes a string parameter and returns a bitmap.

Step 3: Displaying the QR Code

Now that we have our QR code generator ready, let’s move on to displaying the generated QR code in our Android app. Open the layout file where you want to display the QR code (e.g., activity_main.xml) and add an ImageView element:

<ImageView
    android:id="@+id/qr_code_image"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center" />

Next, open the corresponding Java class (e., MainActivity.java) and add the following code inside the onCreate method:

QRCodeGenerator qrCodeGenerator = new QRCodeGenerator();
Bitmap qrCodeBitmap = qrCodeGenerator.generateQRCode("https://example.com");

ImageView qrCodeImageView = findViewById(R.id.qr_code_image);
qrCodeImageView.setImageBitmap(qrCodeBitmap);

This code creates an instance of our QRCodeGenerator class and generates a QR code bitmap using a sample URL. Finally, it sets the generated bitmap as the image resource for the ImageView.

Step 4: Scanning QR Codes

To complete our integration, let’s add the functionality to scan QR codes within our Android app. Create a new Java class called QRCodeScannerActivity.content.Intent;
import android.os.Bundle;
import android.Log;