How can I simply scan barcodes on iPhone and/or iPad?
12 Answers
We produced the 'Barcodes' application for the iPhone. It can decode QR Codes. The source code is available from the zxing project; specifically, you want to take a look at the iPhone client and the partial C++ port of the core library. The port is a little old, from circa the 0.9 release of the Java code, but should still work reasonably well.
If you need to scan other formats, like 1D formats, you could continue the port of the Java code within this project to C++.
EDIT: Barcodes and the iphone code in the project were retired around the start of 2014.
You can find another native iOS solution using Swift 4 and Xcode 9 at below. Native AVFoundation framework used with in this solution.
First part is the a subclass of UIViewController which have related setup and handler functions for AVCaptureSession.
import UIKit
import AVFoundation
class BarCodeScannerViewController: UIViewController {
let captureSession = AVCaptureSession()
var videoPreviewLayer: AVCaptureVideoPreviewLayer!
var initialized = false
let barCodeTypes = [AVMetadataObject.ObjectType.upce,
AVMetadataObject.ObjectType.code39,
AVMetadataObject.ObjectType.code39Mod43,
AVMetadataObject.ObjectType.code93,
AVMetadataObject.ObjectType.code128,
AVMetadataObject.ObjectType.ean8,
AVMetadataObject.ObjectType.ean13,
AVMetadataObject.ObjectType.aztec,
AVMetadataObject.ObjectType.pdf417,
AVMetadataObject.ObjectType.itf14,
AVMetadataObject.ObjectType.dataMatrix,
AVMetadataObject.ObjectType.interleaved2of5,
AVMetadataObject.ObjectType.qr]
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
setupCapture()
// set observer for UIApplicationWillEnterForeground, so we know when to start the capture session again
NotificationCenter.default.addObserver(self,
selector: #selector(willEnterForeground),
name: .UIApplicationWillEnterForeground,
object: nil)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
// this view is no longer topmost in the app, so we don't need a callback if we return to the app.
NotificationCenter.default.removeObserver(self,
name: .UIApplicationWillEnterForeground,
object: nil)
}
// This is called when we return from another app to the scanner view
@objc func willEnterForeground() {
setupCapture()
}
func setupCapture() {
var success = false
var accessDenied = false
var accessRequested = false
let authorizationStatus = AVCaptureDevice.authorizationStatus(for: .video)
if authorizationStatus == .notDetermined {
// permission dialog not yet presented, request authorization
accessRequested = true
AVCaptureDevice.requestAccess(for: .video,
completionHandler: { (granted:Bool) -> Void in
self.setupCapture();
})
return
}
if authorizationStatus == .restricted || authorizationStatus == .denied {
accessDenied = true
}
if initialized {
success = true
} else {
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera,
.builtInTelephotoCamera,
.builtInDualCamera],
mediaType: .video,
position: .unspecified)
if let captureDevice = deviceDiscoverySession.devices.first {
do {
let videoInput = try AVCaptureDeviceInput(device: captureDevice)
captureSession.addInput(videoInput)
success = true
} catch {
NSLog("Cannot construct capture device input")
}
} else {
NSLog("Cannot get capture device")
}
}
if success {
DispatchQueue.global().async {
self.captureSession.startRunning()
DispatchQueue.main.async {
let captureMetadataOutput = AVCaptureMetadataOutput()
self.captureSession.addOutput(captureMetadataOutput)
let newSerialQueue = DispatchQueue(label: "barCodeScannerQueue") // in iOS 11 you can use main queue
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: newSerialQueue)
captureMetadataOutput.metadataObjectTypes = self.barCodeTypes
self.videoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
self.videoPreviewLayer.videoGravity = .resizeAspectFill
self.videoPreviewLayer.frame = self.view.layer.bounds
self.view.layer.addSublayer(self.videoPreviewLayer)
}
}
initialized = true
} else {
// Only show a dialog if we have not just asked the user for permission to use the camera. Asking permission
// sends its own dialog to th user
if !accessRequested {
// Generic message if we cannot figure out why we cannot establish a camera session
var message = "Cannot access camera to scan bar codes"
#if (arch(i386) || arch(x86_64)) && (!os(macOS))
message = "You are running on the simulator, which does not hae a camera device. Try this on a real iOS device."
#endif
if accessDenied {
message = "You have denied this app permission to access to the camera. Please go to settings and enable camera access permission to be able to scan bar codes"
}
let alertPrompt = UIAlertController(title: "Cannot access camera", message: message, preferredStyle: .alert)
let confirmAction = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
self.navigationController?.popViewController(animated: true)
})
alertPrompt.addAction(confirmAction)
self.present(alertPrompt, animated: true, completion: nil)
}
}
}
func handleCapturedOutput(metadataObjects: [AVMetadataObject]) {
if metadataObjects.count == 0 {
return
}
guard let metadataObject = metadataObjects.first as? AVMetadataMachineReadableCodeObject else {
return
}
if barCodeTypes.contains(metadataObject.type) {
if let metaDataString = metadataObject.stringValue {
captureSession.stopRunning()
displayResult(code: metaDataString)
return
}
}
}
func displayResult(code: String) {
let alertPrompt = UIAlertController(title: "Bar code detected", message: code, preferredStyle: .alert)
if let url = URL(string: code) {
let confirmAction = UIAlertAction(title: "Launch URL", style: .default, handler: { (action) -> Void in
UIApplication.shared.open(url, options: [:], completionHandler: { (result) in
if result {
NSLog("opened url")
} else {
let alertPrompt = UIAlertController(title: "Cannot open url", message: nil, preferredStyle: .alert)
let confirmAction = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
})
alertPrompt.addAction(confirmAction)
self.present(alertPrompt, animated: true, completion: {
self.setupCapture()
})
}
})
})
alertPrompt.addAction(confirmAction)
}
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: { (action) -> Void in
self.setupCapture()
})
alertPrompt.addAction(cancelAction)
present(alertPrompt, animated: true, completion: nil)
}
}
Second part is the extension of our UIViewController subclass for AVCaptureMetadataOutputObjectsDelegate where we catch the captured outputs.
extension BarCodeScannerViewController: AVCaptureMetadataOutputObjectsDelegate {
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
handleCapturedOutput(metadataObjects: metadataObjects)
}
}
Update for Swift 4.2
.UIApplicationWillEnterForegroundchanges as UIApplication.willEnterForegroundNotification.
with Swift 5 it's Simple and Super fast!!
You just need to add cocoa pods "BarcodeScanner" here is the full code
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '12.0'
target 'Simple BarcodeScanner'
do
pod 'BarcodeScanner'
end
Make sure add Camera permission in your .plist file
<key>NSCameraUsageDescription</key>
<string>Camera usage description</string>
And add Scanner and handle result in your ViewController this way
import UIKit
import BarcodeScanner
class ViewController: UIViewController, BarcodeScannerCodeDelegate, BarcodeScannerErrorDelegate, BarcodeScannerDismissalDelegate {
override func viewDidLoad() {
super.viewDidLoad()
let viewController = BarcodeScannerViewController()
viewController.codeDelegate = self
viewController.errorDelegate = self
viewController.dismissalDelegate = self
present(viewController, animated: true, completion: nil)
}
func scanner(_ controller: BarcodeScannerViewController, didCaptureCode code: String, type: String) {
print("Product's Bar code is :", code)
controller.dismiss(animated: true, completion: nil)
}
func scanner(_ controller: BarcodeScannerViewController, didReceiveError error: Error) {
print(error)
}
func scannerDidDismiss(_ controller: BarcodeScannerViewController) {
controller.dismiss(animated: true, completion: nil)
}
}
Still and any question or challenges, please check sample application here with full source code
I believe this can be done using AVFramework, here is the sample code to do this
import UIKit
import AVFoundation
class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate
{
@IBOutlet weak var lblQRCodeResult: UILabel!
@IBOutlet weak var lblQRCodeLabel: UILabel!
var objCaptureSession:AVCaptureSession?
var objCaptureVideoPreviewLayer:AVCaptureVideoPreviewLayer?
var vwQRCode:UIView?
override func viewDidLoad() {
super.viewDidLoad()
self.configureVideoCapture()
self.addVideoPreviewLayer()
self.initializeQRView()
}
func configureVideoCapture() {
let objCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
var error:NSError?
let objCaptureDeviceInput: AnyObject!
do {
objCaptureDeviceInput = try AVCaptureDeviceInput(device: objCaptureDevice) as AVCaptureDeviceInput
} catch let error1 as NSError {
error = error1
objCaptureDeviceInput = nil
}
objCaptureSession = AVCaptureSession()
objCaptureSession?.addInput(objCaptureDeviceInput as! AVCaptureInput)
let objCaptureMetadataOutput = AVCaptureMetadataOutput()
objCaptureSession?.addOutput(objCaptureMetadataOutput)
objCaptureMetadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
objCaptureMetadataOutput.metadataObjectTypes = [AVMetadataObjectTypeQRCode]
}
func addVideoPreviewLayer() {
objCaptureVideoPreviewLayer = AVCaptureVideoPreviewLayer(session: objCaptureSession)
objCaptureVideoPreviewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
objCaptureVideoPreviewLayer?.frame = view.layer.bounds
self.view.layer.addSublayer(objCaptureVideoPreviewLayer!)
objCaptureSession?.startRunning()
self.view.bringSubviewToFront(lblQRCodeResult)
self.view.bringSubviewToFront(lblQRCodeLabel)
}
func initializeQRView() {
vwQRCode = UIView()
vwQRCode?.layer.borderColor = UIColor.redColor().CGColor
vwQRCode?.layer.borderWidth = 5
self.view.addSubview(vwQRCode!)
self.view.bringSubviewToFront(vwQRCode!)
}
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
if metadataObjects == nil || metadataObjects.count == 0 {
vwQRCode?.frame = CGRectZero
lblQRCodeResult.text = "QR Code wans't found"
return
}
let objMetadataMachineReadableCodeObject = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if objMetadataMachineReadableCodeObject.type == AVMetadataObjectTypeQRCode {
let objBarCode = objCaptureVideoPreviewLayer?.transformedMetadataObjectForMetadataObject(objMetadataMachineReadableCodeObject as AVMetadataMachineReadableCodeObject) as! AVMetadataMachineReadableCodeObject
vwQRCode?.frame = objBarCode.bounds;
if objMetadataMachineReadableCodeObject.stringValue != nil {
lblQRCodeResult.text = objMetadataMachineReadableCodeObject.stringValue
}
}
}
}
If you are developing for iOS >10.2 with Swift 4 then you can try my solution. I mixed up this and this tutorial and came up with a ViewController which scans a QR Code and print() it out. I also have a Switch in my UI to toggle the camera light, might be helpful as well. For now I only tested it on a iPhone SE, please let me know if it doesn't work on newer iPhones.
Here you go:
import UIKit
import AVFoundation
class QRCodeScanner: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
let captureSession: AVCaptureSession = AVCaptureSession()
var videoPreviewLayer: AVCaptureVideoPreviewLayer?
let qrCodeFrameView: UIView = UIView()
var captureDevice: AVCaptureDevice?
override func viewDidLoad() {
// Get the back-facing camera for capturing videos
let deviceDiscoverySession = AVCaptureDevice.DiscoverySession(deviceTypes: [.builtInWideAngleCamera, .builtInDualCamera], mediaType: AVMediaType.video, position: .back)
captureDevice = deviceDiscoverySession.devices.first
if captureDevice == nil {
print("Failed to get the camera device")
return
}
do {
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
let input = try AVCaptureDeviceInput(device: captureDevice!)
// Set the input device on the capture session.
captureSession.addInput(input)
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession.addOutput(captureMetadataOutput)
// Set delegate and use the default dispatch queue to execute the call back
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
captureMetadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
if let videoPreviewLayer = videoPreviewLayer {
videoPreviewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer)
// Start video capture.
captureSession.startRunning()
if let hasFlash = captureDevice?.hasFlash, let hasTorch = captureDevice?.hasTorch {
if hasFlash && hasTorch {
view.bringSubview(toFront: bottomBar)
try captureDevice?.lockForConfiguration()
}
}
}
// QR Code Overlay
qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView.layer.borderWidth = 2
view.addSubview(qrCodeFrameView)
view.bringSubview(toFront: qrCodeFrameView)
} catch {
// If any error occurs, simply print it out and don't continue any more.
print("Error: \(error)")
return
}
}
// MARK: Buttons and Switch
@IBAction func switchFlashChanged(_ sender: UISwitch) {
do {
if sender.isOn {
captureDevice?.torchMode = .on
} else {
captureDevice?.torchMode = .off
}
}
}
// MARK: AVCaptureMetadataOutputObjectsDelegate
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects.count == 0 {
qrCodeFrameView.frame = CGRect.zero
return
}
// Get the metadata object.
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if metadataObj.type == AVMetadataObject.ObjectType.qr {
// If the found metadata is equal to the QR code metadata then update the status label's text and set the bounds
let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
qrCodeFrameView.frame = barCodeObject!.bounds
print("QR Code: \(metadataObj.stringValue)")
}
}
}
The simplest way is to use 3rd party framework with minimum UI that can be improved. Check QRCodeScanner83
You can simply use the following code (check the documentation on how to create view controller in your storyboard):
import QRCodeScanner83
guard let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(identifier: "CodeScannerViewController") as? CodeScannerViewController else {
return
}
vc.callbackCodeScanned = { code in
print("SCANNED CODE: \(code)")
vc.dismiss(animated: true, completion: nil)
}
self.present(vc, animated: true, completion: nil)
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