如何在iPhone和/或iPad上简单扫描条形码？
我们为iPhone制作了“条形码”应用程序。它可以解码QR码。源代码可从zxing project获得;具体来说，你想看看iPhone client和partial C++ port of the core library。该端口有点陈旧，大约是Java代码的0.9版本，但仍然应该运行得相当好。
如果需要扫描其他格式（如1D格式），可以将此项目中的Java代码端口继续到C ++。
编辑：项目中的条形码和iphone代码在2014年初退役。
如果对iPad 2或iPod Touch的支持对您的应用程序很重要，我会选择条形码扫描仪SDK来解码模糊图像中的条形码，例如我们用于iOS和Android的.UIApplicationWillEnterForeground。解码模糊条形码图像对于具有自动对焦相机的手机也很有用，因为用户无需等待自动对焦启动。
Scandit提供免费的社区价格计划，还有一个产品API，可以很容易地将条形码数字转换为产品名称。
（免责声明：我是Scandit的联合创始人）
你可以看看UIApplication.willEnterForegroundNotification（QR Code library; what QR Codes are），如果它仍然可用。
iPhone相机的问题在于，第一个型号（其中有大量使用的）具有定焦相机，无法在2英尺以下的距离内对焦。图像模糊和失真，如果从更远的距离拍摄，则条形码中没有足够的细节/信息。
一些公司开发了可以通过使用先进的去模糊技术来适应这种情况的iPhone应用程序。您可以在Apple应用商店找到的应用程序：pic2shop，RedLaser和ShopSavvy。所有的公司都宣布他们也有SDK可用 - 一些免费或非常优惠的条款，检查一个。
对于原生iOS 7条形码扫描器，请查看我在GitHub上的项目：
如果您使用Swift 4开发iOS> 10.2，那么您可以尝试我的解决方案。我混合了Google Code project和archived blog post教程并想出了一个ViewController，它扫描QR码和https://github.com/werner77/WECodeScanner它。我的UI中也有一个Switch来切换相机灯，也可能有用。目前我只在iPhone SE上测试过，请告诉我它是否适用于较新的iPhone。
干得好：
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
}
有时，生成QR码也很有用。这里有一个极好的C库，就像一个魅力。它被称为this。编写用于显示QR码的自定义视图并不困难，可以通过对QuartzCore的基本了解来完成。
我相信这可以使用AVFramework来完成，这是执行此操作的示例代码
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)")
}
}
}
使用Swift 5它简单而超级快！
你只需要添加可可豆荚“BarcodeScanner”这里就是完整的代码
libqrencode
确保在.plist文件中添加Camera权限
- (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) {
}
并以这种方式在ViewController中添加Scanner并处理结果
- (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];
}
仍然和任何问题或挑战，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
}
}
}
}
查看ZBar读取QR码和ECN / ISBN代码，并在LGPL v2许可下可用。
与iOS7的发布一样，您不再需要使用外部框架或库。拥有AVFoundation的iOS生态系统现在完全支持扫描从EAN到UPC的QR中的几乎所有代码。
只需看看Tech Note和AVFoundation编程指南。 AVMetadataObjectTypeQRCode是你的朋友。
这是一个很好的教程，一步一步地显示它：iPhone QR code scan library iOS7
关于如何设置它的一个小例子：
#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];
}
iPhone 4相机更能够制作条形码。斑马线条形码库在github qazxsw poi上有一个分叉。它是开源的。
zxing-iphone是github上“从zxing移植的Objective C中的Lite QR阅读器”，并且支持Xcode 4。
qazxsw poi，指向qazxsw poi，看起来很有帮助（qazxsw poi）。
您可以在下面找到使用Swift 4和Xcode 9的另一个原生iOS解决方案。本解决方案中使用的本机ZBar框架。
第一部分是HOWTO: Add a barcode reader to an iPhone app的子类，它具有ZBar iPhone SDK的相关设置和处理函数。
from another thread
第二部分是AVFoundation的UIViewController子类的扩展，我们捕获捕获的输出。
AVCaptureSession更新Swift 4.2
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)
}
}
changes为UIViewController。
不确定这是否有用，但这里是一个开源AVCaptureMetadataOutputObjectsDelegate的链接。正如你所看到的，有几个人已经用它来为iPhone创建应用程序。
维基百科有一篇文章解释extension BarCodeScannerViewController: AVCaptureMetadataOutputObjectsDelegate {
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
handleCapturedOutput(metadataObjects: metadataObjects)
}
}
。在我看来，QR码比iphone所关注的标准条码更适合用途，因为它是为这种类型的实现而设计的。