Disable rotation only for AVCaptureVideoPreviewLayer - ios

I have a UITabBarController which has 4 items tabs. One of them is an AvCaptureVideoPreviewLayer (is a barcode scanner). What I would like to do is to disable autorotate only for AVCaptureVideoPreviewLayer (like iOS camera app) but not for the item bar which would rotate with the screen. It is a bit difficult situation because I think that the UITabBarConrtoller doesn't allow you easily to disable rotation.
The code for my camera view is:
import UIKit
import AVFoundation
class ScannerViewController: UIViewController,
// MARK: Properties
/// Manages the data flow from the capture stage through our input devices.
var captureSession: AVCaptureSession!
/// Dispays the data as captured from our input device.
var previewLayer: AVCaptureVideoPreviewLayer!
// MARK: Methods
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.blackColor()
self.captureSession = AVCaptureSession()
// This object represents a physical capture device and the properties associated with that device
let videoCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
// Is useful for capturing the data from the input device
let videoInput: AVCaptureDeviceInput
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
// TODO: maybe show an alert
return
}
if (self.captureSession.canAddInput(videoInput)) {
self.captureSession.addInput(videoInput)
} else {
failed();
return;
}
let metadataOutput = AVCaptureMetadataOutput()
if (self.captureSession.canAddOutput(metadataOutput)) {
self.captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
metadataOutput.metadataObjectTypes = [AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypePDF417Code,
AVMetadataObjectTypeUPCECode, AVMetadataObjectTypeCode39Code,
AVMetadataObjectTypeCode39Mod43Code, AVMetadataObjectTypeCode93Code,
AVMetadataObjectTypeCode128Code]
} else {
failed()
return
}
// Adds the preview layer to display the captured data. Sets the videoGravity to AspectFill so that it covers the full screen
self.previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession);
self.previewLayer.frame = self.view.layer.bounds;
self.previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
self.view.layer.addSublayer(previewLayer);
self.captureSession.startRunning();
}
override func viewDidLayoutSubviews() {
self.previewLayer?.frame = self.view.layer.bounds;
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
if (self.captureSession.running == false) {
self.captureSession.startRunning();
}
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if (self.captureSession.running == true) {
self.captureSession.stopRunning();
}
}
func failed() {
let ac = UIAlertController(title: "Scanning not supported", message: "Your device does not support scanning a code from an item. Please use a device with a camera.", preferredStyle: .Alert)
ac.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
presentViewController(ac, animated: true, completion: nil)
self.captureSession = nil
}
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
self.captureSession.stopRunning()
if let metadataObject = metadataObjects.first {
let readableObject = metadataObject as! AVMetadataMachineReadableCodeObject;
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
foundCode(readableObject.stringValue);
}
}
/// Completes some tasks when a barcode is found.
///
/// - parameter code: The the barcode found.
func foundCode(code: String) {
}
}

I'm not 100% sure if I understand it correctly. But what you could do is:
1 - Subclass your UITabBarController and override shouldAutorotate with something like this:
override var shouldAutorotate: Bool {
guard let viewController = tabBarController?.selectedViewController else { return false }
return viewController.shouldAutorotate
}
This means that the selected UIViewController will define if it should autorotate.
2 - Now that the UITabBarController will ask its ViewControllers if it should autorotate, you have to override shouldAutorotate in every controller as well.
And that's it!
Sorry if I misunderstood your question. If you provide more information it would help.
Take care :)

Related

iOS barcode scanner App crashes with no crash log

I am trying to make a barcode scanner app. As soon as the camera session begins, the app crashes within a few seconds.
I am unable to find the reason behind this. and, how to fix this one.
I have used https://www.appcoda.com/barcode-reader-swift/ to make the barcde scanner.
import Foundation
import UIKit
import AVFoundation
import CoreData
enum BarcodeScanError : String{
case cameraLoadFailed = "Camera Load Failed"
case NoValidBarcode = "No Valid Barcode"
}
class ScanBoardingPassViewController : UIViewController {
//MARK: - Properties
var viewModel : ScanBoardingPassViewModel? = nil
var captureSession : AVCaptureSession?
var videoPreviewLayer: AVCaptureVideoPreviewLayer?
var qrCodeFrameView: UIView?
private let supportedCodeTypes = [AVMetadataObject.ObjectType.aztec,
AVMetadataObject.ObjectType.pdf417]
//MARK: - Outlets
#IBOutlet weak var btnCancel: UIButton!
//MARK: - View Life Cycle
override func viewDidLoad() {
viewModel = ScanBoardingPassViewModel()
self.captureSession = AVCaptureSession()
self.setUpView()
super.viewDidLoad()
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
//MARK: - Set Up View
func setUpView() {
self.setUpBarCodeScanner()
self.view.bringSubviewToFront(self.btnCancel)
self.setUpBarcodeRecognizerFrame()
}
private func setUpBarCodeScanner() {
// Get the back-facing camera for capturing videos
guard let captureDevice = AVCaptureDevice.default(for: AVMediaType.video) else {
debugPrint(BarcodeScanError.cameraLoadFailed)
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 = supportedCodeTypes
// captureMetadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
} catch {
// If any error occurs, simply print it out and don't continue any more.
print(error)
return
}
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
// Start video capture.
captureSession?.startRunning()
}
private func setUpBarcodeRecognizerFrame() {
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
if let qrCodeFrameView = qrCodeFrameView {
qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView.layer.borderWidth = 2
view.addSubview(qrCodeFrameView)
view.bringSubviewToFront(qrCodeFrameView)
}
}
//MARK: - Outlets
#IBAction func btnCancelPressed(_ sender: UIButton) {
self.dismissView()
}
func dismissView() {
self.dismiss(animated: true, completion: nil)
}
}
extension ScanBoardingPassViewController: 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
debugPrint(BarcodeScanError.NoValidBarcode)
return
}
// Get the metadata object.
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if supportedCodeTypes.contains(metadataObj.type) {
// If the found metadata is equal to the QR code metadata (or barcode) then update the status label's text and set the bounds
let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
qrCodeFrameView?.frame = barCodeObject!.bounds
if metadataObj.stringValue != nil {
captureSession?.stopRunning()
debugPrint("Valid Barcode found \(metadataObj.stringValue!)")
if let boardingPass = viewModel?.parseBoardingPassString(boardingPassString : metadataObj.stringValue!) {
let unitOfWork = UnitOfWork(context:( UIApplication.shared.delegate as! AppDelegate).persistentContainer.newBackgroundContext() )
unitOfWork.boardingPassRepository.saveBoardingPasses(boardingPass: boardingPass)
unitOfWork.saveChanges()
print(unitOfWork.boardingPassRepository.getBoardingPasses(predicate: nil))
self.dismissView()
}
}
}
}
}
The camera doesnt get struck. But, the app gives an lldb everytime within a few seconds.
// Created by Satya Narayana on 17/11/20.
//
import UIKit
import AVFoundation
import UIKit
class QRViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
//MARK: Outlets
#IBOutlet weak var qrLbl: UILabel! // BarCode displaying Label
#IBOutlet weak var sView: UIView! // View
//MARK: Variables
var captureSession: AVCaptureSession!
var previewLayer: AVCaptureVideoPreviewLayer!
//MARK: View Methods
override func viewDidLoad() {
super.viewDidLoad()
captureSession = AVCaptureSession()
guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else { return }
let videoInput: AVCaptureDeviceInput
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
return
}
if (captureSession.canAddInput(videoInput)) {
captureSession.addInput(videoInput)
} else {
failed()
return
}
let metadataOutput = AVCaptureMetadataOutput()
if (captureSession.canAddOutput(metadataOutput)) {
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
metadataOutput.metadataObjectTypes = [.qr, .ean13, .code128]
} else {
failed()
return
}
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.frame = sView.layer.bounds
previewLayer.videoGravity = .resizeAspectFill
sView.layer.addSublayer(previewLayer)
captureSession.startRunning()
}
func failed() {
self.showToast(message: "Scanning not supported.Your device does not support scanning a code from an item. Please use a device with a camera.", seconds: 1.0)
captureSession = nil
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
qrLbl.isHidden = true
if (captureSession?.isRunning == false) {
captureSession.startRunning()
}
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if (captureSession?.isRunning == true) {
captureSession.stopRunning()
}
}
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
captureSession.stopRunning()
if let metadataObject = metadataObjects.first {
guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else { return }
guard let stringValue = readableObject.stringValue else { return }
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
found(code: stringValue)
}
dismiss(animated: true)
}
//MARK:- Found BARCODE
func found(code: String) {
print(code)
if code != ""{
print(code) // This is Barcode
qrLbl.text = code
}else{
// if you need run again uncomment below line
//self.captureSession.startRunning()
}
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
return .portrait
}
}

How do I get the camera functionality to display in only one tab bar item?

I am currently creating a QR scanner/ reader application in Xcode 10. I have a Tab controller that has two tab bar items.
1.) Home
2.) QR Scanner
Although, my code works and I can scan a QR code in the "second view controller", whenever I switch to the "first view controller", it still scans the QR code when i don't want it to. If you have any tips on how I can fix this issue, it would be much appreciated.
First View Controller:
import UIKit
class FirstViewController: UIViewController{
override func viewDidLoad() {
super.viewDidLoad()
}
}
Second View Controller:
import UIKit
import AVFoundation
class SecondViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
var video = AVCaptureVideoPreviewLayer()
#IBOutlet weak var square: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
//Creating session
let session = AVCaptureSession()
//Define Capture device
let captureDevice = AVCaptureDevice.default(for: AVMediaType.video)
do {
let input = try AVCaptureDeviceInput(device: captureDevice!)
session.addInput(input)
} catch {
print (">>>>Error")
}
let output = AVCaptureMetadataOutput ()
session.addOutput(output)
output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
output.metadataObjectTypes = [AVMetadataObject.ObjectType.qr]
video = AVCaptureVideoPreviewLayer(session: session)
video.frame = view.layer.bounds
view.layer.addSublayer(video)
self.view.bringSubviewToFront(square)
session.startRunning()
}
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
if metadataObjects != nil && metadataObjects.count != 0 {
if let object = metadataObjects[0] as? AVMetadataMachineReadableCodeObject{
if object.type == AVMetadataObject.ObjectType.qr{
let alert = UIAlertController(title: "QR code", message: object.stringValue, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Retake", style: .default, handler: nil))
present(alert,animated: true, completion: nil)
}
}
}
}
}
I would recommend adding the session as a member variable in your class instead of only the viewDidLoad() method.
Now in your viewWillAppear() method you can call the session.startRunning() and in viewWillDisappear you want to call session.stopRunning()
Here is a basic layout:
class SecondViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
let session = AVCaptureSession()
override func viewDidLoad() {
// any setup you may need
}
override func viewWillAppear() {
// ensure everything is setup correctly
session.startRunning()
}
override func viewWillDisappear() {
// anything before navigating away
session.stopRunning()
}
}
You have started the AVCaptureSession session but you don't explicitly stop it. Whenever switching between controllers the system might keep the controller in memory.
You will want to execute session.stopRunning() prior to navigating away from the controller and clean up. E.g. in viewWillDisappear or simiilar.
Ref: https://developer.apple.com/documentation/avfoundation/avcapturesession/1385661-stoprunning
Thank you everyone for your assistance. After reviewing my code I realized that what I had to do was override the viewDidAppear() and viewDidDisappear().
Working Code:
class SecondViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
let session = AVCaptureSession()
override func viewDidLoad() {
// any setup you may need
}
override func viewWillAppear(_ animated: Bool) {
session.startRunning()
print("Start running")
}
override func viewDidDisappear(_ animated: Bool) {
session.stopRunning()
print ("Stop running")
}
}

QR Code Scanning not working

So I have just taken over an iOS project as their first in-house dev, where previously this app had been developed by an agency.
One of the features of the app is that it needs to scan QR codes—by the look of the code the previous developers have followed this tutorial on AppCoda to implement the QR scan. Everything looks fine and I can't see anything wrong with the code yet it isn't working.
I also downloaded the completed tutorial project and that worked when I tried the QR scan. I also tried copying and pasting every single line so that it was identical to the working tutorial yet no luck.
I'm tearing my hair out trying to figure out why it isn't working.
Any help is much appreciated!
enum ScanState : Int {
case newDevice = 1
case resetDevice = 2
case replaceDevice = 3
}
class QRScannerViewController: BaseViewController,AVCaptureMetadataOutputObjectsDelegate {
#IBOutlet var scanZoneView: UIView!
#IBOutlet var scannerVIew: UIView!
#IBOutlet var scanInfoLabel: UILabel!
var capturedQR: String? = nil
var captureSession:AVCaptureSession?
var videoPreviewLayer:AVCaptureVideoPreviewLayer?
var qrCodeFrameView:UIView?
let supportedBarCodes = [AVMetadataObject.ObjectType.qr, AVMetadataObject.ObjectType.code128, AVMetadataObject.ObjectType.code39, AVMetadataObject.ObjectType.code93, AVMetadataObject.ObjectType.upce, AVMetadataObject.ObjectType.pdf417, AVMetadataObject.ObjectType.ean13, AVMetadataObject.ObjectType.aztec]
var type = "leg scan"
var device:Device?
var state:ScanState = .newDevice
override func viewDidLoad() {
super.viewDidLoad()
scanInfoLabel.text = "Scan your existing\nleg QR code"
self.navigationController?.navigationBar.dark()
//self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.setNavigationBarHidden(false, animated: true)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
#if NOHARDWARE
moveToNextViewController()
#else
initiateCapture()
#endif
}
func initiateCapture() {
let captureDevice = AVCaptureDevice.default(for: AVMediaType.video)
// Get an instance of the AVCaptureDeviceInput class using the previous device object.
var error:NSError?
let input: AnyObject!
do {
input = try AVCaptureDeviceInput(device: captureDevice!) as AVCaptureDeviceInput
} catch let error1 as NSError {
error = error1
input = nil
} catch _ {
input = nil
}
if (error != nil) {
// If any error occurs, simply log the description of it and don't continue any more.
print("\(error?.localizedDescription)")
return
}
// Initialize the captureSession object.
captureSession = AVCaptureSession()
// Set the input device on the capture session.
captureSession?.addInput(input as! AVCaptureInput)
// 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 = supportedBarCodes
// Initialize the video preview layer and add it as a sublayer to the viewPreview view's layer.
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer?.frame = scannerVIew.layer.bounds
scannerVIew.layer.addSublayer(videoPreviewLayer!)
// Start video capture.
captureSession?.startRunning()
// Initialize QR Code Frame to highlight the QR code
qrCodeFrameView = UIView()
qrCodeFrameView?.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView?.layer.borderWidth = 2
scannerVIew.addSubview(qrCodeFrameView!)
scannerVIew.bringSubview(toFront: qrCodeFrameView!)
//qrCapturedLabel.text = "No QR code is detected"
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func metadataOutput(captureOutput: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
// Check if the metadataObjects array is not nil and it contains at least one object.
if metadataObjects == nil || metadataObjects.count == 0 {
qrCodeFrameView?.frame = CGRect.zero
return
}
// Get the metadata object.
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
// Here we use filter method to check if the type of metadataObj is supported
// Instead of hardcoding the AVMetadataObjectTypeQRCode, we check if the type
// can be found in the array of supported bar codes.
if supportedBarCodes.filter({ $0 == metadataObj.type }).count > 0 {
// 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 as AVMetadataMachineReadableCodeObject) as! AVMetadataMachineReadableCodeObject
let intersectionRect = barCodeObject.bounds.intersection(self.scanZoneView.frame)
if !intersectionRect.isNull &&
(intersectionRect.size.width * intersectionRect.size.height) > self.scanZoneView.bounds.width * self.scanZoneView.bounds.height / 7 {
qrCodeFrameView?.frame = barCodeObject.bounds
if process(metadataObj.stringValue!) {
captureSession?.stopRunning()
}
}
}
}
#IBAction func didTapCancel(_ sender: AnyObject) {
self.dismiss(animated: true, completion: nil)
}
}
extension QRScannerViewController {
func process(_ scanText : String) -> Bool {
var legCode : String
let codeComponents = scanText.components(separatedBy: ";")
if codeComponents.count > 0 {
legCode = codeComponents[0]
} else {
// Invalid number of parameters seperated by a ;
return false
}
// TODO Validate the LEG to LEG-XXXXX
if legCode.hasPrefix("LEG-") {
let delta: Int64 = 1 * Int64(NSEC_PER_SEC)
let time = DispatchTime.now() + Double(delta) / Double(NSEC_PER_SEC)
DispatchQueue.main.asyncAfter(deadline: time, execute: {
switch self.state {
case .resetDevice:
let realm = try! Realm()
let deviceList = realm.objects(Device.self)
let lc = legCode
self.device = deviceList.filter("legCode = %#", lc).first
if self.device == nil {
// TODO Error message: Device not associated with LEG
let vc = ErrorViewController.createErrorViewController(.DeviceNotFound)
self.present(vc, animated: true, completion: nil)
return
}
self.moveToNextViewController()
default:
self.presentingViewController?.dismiss(animated: true, completion: nil)
}
});
return true
}
return false
}
func moveToNextViewController() {
let inspectionStoryboard = UIStoryboard(name: "Impact", bundle: nil)
if let resetVC = inspectionStoryboard.instantiateViewController(withIdentifier: ImpactDetectionViewController.storyboardID) as? ImpactDetectionViewController {
resetVC.device = device
// TODO Pass the impact type across too when the G2 API is set
self.navigationController?.pushViewController(resetVC, animated: false)
}
}
#IBAction func cancelToVC(_ segue: UIStoryboardSegue) { }
}
EDIT
By not working I mean the delegate for AVCaptureMetadataOutputObjectsDelegate is never being called so it never seems to be detecting a QR code. In the AppCoda tutorial it overlays a green square where it detects the QR code but this never happens when I put that code into this app.
The camera is actually running but QR codes are never deteced.
Turns out the answer was deceptively (and annoyingly) simple! Of course in Swift 4 the delegates have been renamed slightly. To fix all I had to was change
func metadataOutput(captureOutput: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
to
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
You're not connecting your class to AVCaptureMetadataOutput's delegate, that's why the AVCaptureMetadataOutputObjectsDelegate functions are not being invoked. More info: https://developer.apple.com/documentation/avfoundation/avcapturemetadataoutputobjectsdelegate
Try this:
// Initialize a AVCaptureMetadataOutput object and set it as the output device to the capture session.
let captureMetadataOutput = AVCaptureMetadataOutput()
captureMetadataOutput.metadataObjectsDelegate = self // assign self to the delegate.
captureSession?.addOutput(captureMetadataOutput)

Adding objects over camera view in barcode scanner app (Swift 3)

On my storyboard, I have a view controller, that has the following class associated with it:
import AVFoundation
import UIKit
class ScannerViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
var captureSession: AVCaptureSession!
var previewLayer: AVCaptureVideoPreviewLayer!
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = UIColor.black
captureSession = AVCaptureSession()
let videoCaptureDevice = AVCaptureDevice.defaultDevice(withMediaType: AVMediaTypeVideo)
let videoInput: AVCaptureDeviceInput
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
return
}
if (captureSession.canAddInput(videoInput)) {
captureSession.addInput(videoInput)
} else {
failed();
return;
}
let metadataOutput = AVCaptureMetadataOutput()
if (captureSession.canAddOutput(metadataOutput)) {
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
metadataOutput.metadataObjectTypes = [AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypePDF417Code, AVMetadataObjectTypeCode39Code]
} else {
failed()
return
}
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession);
previewLayer.frame = view.layer.bounds;
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
view.layer.addSublayer(previewLayer);
captureSession.startRunning();
}
func failed() {
let ac = UIAlertController(title: "Scanning not supported", message: "Your device does not support scanning a code from an item. Please use a device with a camera.", preferredStyle: .alert)
ac.addAction(UIAlertAction(title: "OK", style: .default))
present(ac, animated: true)
captureSession = nil
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if (captureSession?.isRunning == false) {
captureSession.startRunning();
}
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if (captureSession?.isRunning == true) {
captureSession.stopRunning();
}
}
func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) {
captureSession.stopRunning()
let initialView: PLLogViewController = presentingViewController as! PLLogViewController
if let metadataObject = metadataObjects.first {
let readableObject = metadataObject as! AVMetadataMachineReadableCodeObject;
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
found(code: readableObject.stringValue);
initialView.setResults(code: readableObject.stringValue)
}
dismiss(animated: true)
}
func found(code: String) {
print(code)
}
override var supportedInterfaceOrientations: UIInterfaceOrientationMask {
return .portrait
}
}
This code basically initiates a camera view that acts as a barcode scanner. If you point your device at a barcode, it'll detect the barcode, and push the results to a text field.
This all works great. My question is - I would like to have some other elements showing on the screen. Right now, my entire screen is being overtaken by the camera, and so if you access this view, you either HAVE to scan a barcode, or you have to shut down the app.
I attempted to add other elements in the view just by dragging them from the object library, however, the camera seems to overlay those items, making them inaccessible.
There are two elements that I would like to add over top of the camera view. The first is an image, that looks like a "bracket" to give some indication of where the user should "fit" the barcode they are scanning.
The second is a button that allows the user to cancel out of the camera view.
So ultimately, my question is simply, how can I add elements over top of a camera view that is being initialized programmatically?
add a view in you view controller were you want your video preview to appear then simply add the preview layer to that layer instead of the whole view.
Like so:
// Initialize the video preview layer and add it as a sublayer to your views layer.
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer?.videoGravity = AVLayerVideoGravityResizeAspectFill
previewLayer?.frame = /*your views name here i e qrView*/.layer.bounds
/*your views name here i e qrView*/.layer.addSublayer(videoPreviewLayer!)
// instead of
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession);
previewLayer.frame = view.layer.bounds;
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
view.layer.addSublayer(previewLayer);

How can I scan barcodes on iOS? [closed]

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How can I simply scan barcodes on iPhone and/or iPad?
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.
As with the release of iOS7 you no longer need to use an external framework or library. The iOS ecosystem with AVFoundation now fully supports scanning almost every code from QR over EAN to UPC.
Just have a look at the Tech Note and the AVFoundation programming guide. AVMetadataObjectTypeQRCode is your friend.
Here is a nice tutorial which shows it step by step:
iPhone QR code scan library iOS7
Just a little example on how to set it up:
#pragma mark -
#pragma mark AVFoundationScanSetup
- (void) setupScanner;
{
self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
self.input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];
self.session = [[AVCaptureSession alloc] init];
self.output = [[AVCaptureMetadataOutput alloc] init];
[self.session addOutput:self.output];
[self.session addInput:self.input];
[self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
self.output.metadataObjectTypes = #[AVMetadataObjectTypeQRCode];
self.preview = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill;
self.preview.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
AVCaptureConnection *con = self.preview.connection;
con.videoOrientation = AVCaptureVideoOrientationLandscapeLeft;
[self.view.layer insertSublayer:self.preview atIndex:0];
}
There are two major libraries:
ZXing a library written in Java and then ported to Objective C / C++ (QR code only). And an other port to ObjC has been done, by TheLevelUp: ZXingObjC
ZBar an open source software for reading bar codes, C based.
According to my experiments, ZBar is far more accurate and fast than ZXing, at least on iPhone.
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.
If support for the iPad 2 or iPod Touch is important for your application, I'd choose a barcode scanner SDK that can decode barcodes in blurry images, such as our Scandit barcode scanner SDK for iOS and Android. Decoding blurry barcode images is also helpful on phones with autofocus cameras because the user does not have to wait for the autofocus to kick in.
Scandit comes with a free community price plan and also has a product API that makes it easy to convert barcode numbers into product names.
(Disclaimer: I'm a co-founder of Scandit)
The problem with iPhone camera is that the first models (of which there are tons in use) have a fixed-focus camera that cannot take picture in-focus for distances under 2ft. The images are blurry and distorted and if taken from greater distance there is not enough detail/information from the barcode.
A few companies have developed iPhone apps that can accomodate for that by using advanced de-blurring technologies. Those applications you can find on Apple app store: pic2shop, RedLaser and ShopSavvy. All of the companies have announced that they have also SDKs available - some for free or very preferential terms, check that one out.
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
}
}
}
}
Here is simple code:
func scanbarcode()
{
view.backgroundColor = UIColor.blackColor()
captureSession = AVCaptureSession()
let videoCaptureDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
let videoInput: AVCaptureDeviceInput
do {
videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
} catch {
return
}
if (captureSession.canAddInput(videoInput)) {
captureSession.addInput(videoInput)
} else {
failed();
return;
}
let metadataOutput = AVCaptureMetadataOutput()
if (captureSession.canAddOutput(metadataOutput)) {
captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
metadataOutput.metadataObjectTypes = [AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypePDF417Code]
} else {
failed()
return
}
previewLayer = AVCaptureVideoPreviewLayer(session: captureSession);
previewLayer.frame = view.layer.bounds;
previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
view.layer.addSublayer(previewLayer);
view.addSubview(closeBtn)
view.addSubview(backimg)
captureSession.startRunning();
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func failed() {
let ac = UIAlertController(title: "Scanning not supported", message: "Your device does not support scanning a code from an item. Please use a device with a camera.", preferredStyle: .Alert)
ac.addAction(UIAlertAction(title: "OK", style: .Default, handler: nil))
presentViewController(ac, animated: true, completion: nil)
captureSession = nil
}
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
if (captureSession?.running == false) {
captureSession.startRunning();
}
}
override func viewWillDisappear(animated: Bool) {
super.viewWillDisappear(animated)
if (captureSession?.running == true) {
captureSession.stopRunning();
}
}
func captureOutput(captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [AnyObject]!, fromConnection connection: AVCaptureConnection!) {
captureSession.stopRunning()
if let metadataObject = metadataObjects.first {
let readableObject = metadataObject as! AVMetadataMachineReadableCodeObject;
AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
foundCode(readableObject.stringValue);
}
// dismissViewControllerAnimated(true, completion: nil)
}
func foundCode(code: String) {
var createAccountErrorAlert: UIAlertView = UIAlertView()
createAccountErrorAlert.delegate = self
createAccountErrorAlert.title = "Alert"
createAccountErrorAlert.message = code
createAccountErrorAlert.addButtonWithTitle("ok")
createAccountErrorAlert.addButtonWithTitle("Retry")
createAccountErrorAlert.show()
NSUserDefaults.standardUserDefaults().setObject(code, forKey: "barcode")
NSUserDefaults.standardUserDefaults().synchronize()
ItemBarcode = code
print(code)
}
override func prefersStatusBarHidden() -> Bool {
return true
}
override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
return .Portrait
}
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)")
}
}
}
you can check ZBarSDK to reads QR Code and ECN/ISBN codes it's simple to integrate try the following code.
- (void)scanBarcodeWithZBarScanner
{
// ADD: present a barcode reader that scans from the camera feed
ZBarReaderViewController *reader = [ZBarReaderViewController new];
reader.readerDelegate = self;
reader.supportedOrientationsMask = ZBarOrientationMaskAll;
ZBarImageScanner *scanner = reader.scanner;
// TODO: (optional) additional reader configuration here
// EXAMPLE: disable rarely used I2/5 to improve performance
[scanner setSymbology: ZBAR_I25
config: ZBAR_CFG_ENABLE
to: 0];
//Get the return value from controller
[reader setReturnBlock:^(BOOL value) {
}
and in didFinishPickingMediaWithInfo we get bar code value.
- (void) imagePickerController: (UIImagePickerController*) reader
didFinishPickingMediaWithInfo: (NSDictionary*) info
{
// ADD: get the decode results
id<NSFastEnumeration> results =
[info objectForKey: ZBarReaderControllerResults];
ZBarSymbol *symbol = nil;
for(symbol in results)
// EXAMPLE: just grab the first barcode
break;
// EXAMPLE: do something useful with the barcode data
barcodeValue = symbol.data;
// EXAMPLE: do something useful with the barcode image
barcodeImage = [info objectForKey:UIImagePickerControllerOriginalImage];
[_barcodeIV setImage:barcodeImage];
//set the values for to TextFields
[self setBarcodeValue:YES];
// ADD: dismiss the controller (NB dismiss from the *reader*!)
[reader dismissViewControllerAnimated:YES completion:nil];
}
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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