如何在 iPhone 和/或 iPad 上简单地扫描条形码？
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144788 次
12 回答
84
我们为 iPhone 制作了“条形码”应用程序。它可以解码二维码。源代码可从zxing 项目获得；具体来说，你想看看iPhone 客户端和核心库的部分 C++ 端口。该端口有点旧，大约从 Java 代码的 0.9 版本开始，但应该仍然可以正常工作。
如果您需要扫描其他格式，例如 1D 格式，您可以继续将此项目中的 Java 代码移植到 C++。
编辑：iphone项目中的条码和代码在 2014 年初左右停用。
于 2009-05-14T10:43:32.893 回答
57
随着发布iOS7您不再需要使用外部框架或库。带有 AVFoundation 的 iOS 生态系统现在完全支持扫描几乎所有代码，从 QR over EAN 到 UPC。
只需查看技术说明和 AVFoundation 编程指南。AVMetadataObjectTypeQRCode是你的朋友。
这是一个很好的教程，一步一步地展示它： iPhone QR码扫描库iOS7
只是一个关于如何设置它的小例子：
#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];
}
于 2013-10-14T08:32:18.323 回答
7
您可以在下面找到另一个使用Swift 4和Xcode 9的原生 iOS 解决方案。AVFoundation此解决方案中使用的本机框架。
第一部分是一个子类，UIViewController它具有相关的设置和处理函数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)
}
}
第二部分是我们捕获捕获输出的UIViewController子类的扩展。AVCaptureMetadataOutputObjectsDelegate
extension BarCodeScannerViewController: AVCaptureMetadataOutputObjectsDelegate {
func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
handleCapturedOutput(metadataObjects: metadataObjects)
}
}
Swift 4.2 更新
.UIApplicationWillEnterForeground变化为UIApplication.willEnterForegroundNotification.
于 2018-05-14T12:23:51.493 回答
5
如果对 iPad 2 或 iPod Touch 的支持对您的应用程序很重要，我会选择可以解码模糊图像中的条码的条码扫描器 SDK，例如我们的适用于 iOS 和 Android 的Scandit 条码扫描器 SDK。解码模糊的条形码图像在配备自动对焦摄像头的手机上也很有帮助，因为用户不必等待自动对焦启动。
Scandit 提供免费的社区价格计划，还有一个产品 API，可以轻松将条形码编号转换为产品名称。
（免责声明：我是 Scandit 的联合创始人）
于 2012-09-25T11:49:36.737 回答
3
iPhone 相机的问题在于，第一批型号（其中有大量使用中）有一个定焦相机，无法在 2 英尺以下的距离内对焦。图像模糊且失真，如果从更远的距离拍摄，则条形码中的细节/信息不足。
一些公司开发了 iPhone 应用程序，可以通过使用先进的去模糊技术来适应这种情况。您可以在 Apple 应用商店中找到这些应用程序：pic2shop、RedLaser 和 ShopSavvy。所有的公司都宣布他们也有 SDK 可用——一些是免费的或非常优惠的条款，请查看那个。
于 2009-12-07T04:12:01.600 回答
2
使用Swift 5，它既简单又超级快！！
你只需要添加可可豆荚“BarcodeScanner”这里是完整的代码
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '12.0'
target 'Simple BarcodeScanner'
do
pod 'BarcodeScanner'
end
确保在您的 .plist 文件中添加相机权限
<key>NSCameraUsageDescription</key>
<string>Camera usage description</string>
并以这种方式在您的 ViewController 中添加 Scanner 和处理结果
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)
}
}
仍然有任何问题或挑战，请在此处查看示例应用程序以及完整的源代码
于 2019-06-06T10:21:20.290 回答
1
这是简单的代码：
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
}
于 2016-05-02T08:42:57.377 回答
1
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 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
}
}
}
}
于 2016-10-17T01:48:24.657 回答
1
如果您正在使用 Swift 4 为 iOS >10.2 进行开发，那么您可以尝试我的解决方案。我把这个和这个教程混在一起，想出了一个 ViewController，它可以扫描二维码并将print()其输出。我的 UI 中还有一个开关来切换相机灯，这也可能会有所帮助。目前我只在 iPhone SE 上进行了测试，如果它不适用于较新的 iPhone，请告诉我。
干得好：
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)")
}
}
}
于 2018-05-17T16:25:36.310 回答
0
您可以检查 ZBarSDK 以读取 QR 码和 ECN/ISBN 码，它很容易集成尝试以下代码。
- (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) {
}
在 didFinishPickingMediaWithInfo 我们得到条形码值。
- (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];
}
于 2015-06-22T12:16:31.793 回答
0
最简单的方法是使用可以改进的最小 UI 的 3rd 方框架。检查QRCodeScanner83
您可以简单地使用以下代码（查看有关如何在情节提要中创建视图控制器的文档）：
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)
于 2020-12-03T14:02:09.927 回答