If you are a software developer looking to create an Android app with a QR code scanner, this comprehensive tutorial will guide you through the process. We will be using the popular ZXing library to implement the QR code scanner.
Prerequisites
- Android Studio installed on your computer
- Basic understanding of Android app development and Java
Step 1: Create a new Android project
Open Android Studio and create a new project. Select "Empty Activity" and click "Next". Name your project and choose a package name, then click "Finish" to create the project.
Step 2: Add ZXing dependencies
In your project's build.gradle (Module: app) file, add the following dependencies:
implementation 'com.journeyapps:zxing-android-embedded:4.1.0'implementation 'com.google.zxing:core:3.3.3'Click "Sync Now" to download the required libraries.
Step 3: Add camera permissions
In your AndroidManifest.xml file, add the following permissions:
<uses-permission android:name="android.permission.CAMERA" /><uses-feature android:name="android.hardware.camera" /><uses-feature android:name="android.hardware.camera.autofocus" />Step 4: Create a QR code scanner activity
Create a new Java class named "QRCodeScannerActivity" and extend AppCompatActivity. Override the onCreate method and request camera permissions before initializing the QR code scanner:
import android.Manifest;import android.content.pm.PackageManager;import android.os.Build;import android.os.Bundle;import android.widget.Toast;import androidx.annotation.NonNull;import androidx.appcompat.app.AppCompatActivity;import androidx.core.app.ActivityCompat;public class QRCodeScannerActivity extends AppCompatActivity { private static final int PERMISSION_REQUEST_CAMERA = 1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { if (checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) { ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, PERMISSION_REQUEST_CAMERA); } else { initQRCodeScanner(); } } else { initQRCodeScanner(); } } private void initQRCodeScanner() { // Initialize QR code scanner here } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { if (requestCode == PERMISSION_REQUEST_CAMERA) { if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { initQRCodeScanner(); } else { Toast.makeText(this, "Camera permission is required", Toast.LENGTH_LONG).show(); finish(); } } }}Step 5: Implement the QR code scanning functionality
In the "initQRCodeScanner" method, create an instance of the ZXing scanner and set the required configurations:
private void initQRCodeScanner() { IntentIntegrator integrator = new IntentIntegrator(this); integrator.setDesiredBarcodeFormats(IntentIntegrator.QR_CODE); integrator.setOrientationLocked(true); integrator.setPrompt("Scan a QR code"); integrator.initiateScan();}Override the onActivityResult method to handle the scanned QR code:
@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) { IntentResult result = IntentIntegrator.parseActivityResult(requestCode, resultCode, data); if (result != null) { if (result.getContents() == null) { Toast.makeText(this, "Scan cancelled", Toast.LENGTH_LONG).show(); } else { Toast.makeText(this, "Scanned: " + result.getContents(), Toast.LENGTH_LONG).show(); } } else { super.onActivityResult(requestCode, resultCode, data); }}Step 6: Test your app
Run your app on an Android device or emulator and test the QR code scanning functionality. Ensure that the camera permission is granted and that the QR code scanner works as expected.
Conclusion
In this tutorial, we implemented a QR code scanner in an Android app using the ZXing library. You can now use this knowledge to create your own Android apps with QR code scanning capabilities. To hire Android developers, visit Reintech.
