iOS_从相机或相册里扫描二维码或条形码
文章目录
1. 从相机里扫描
1.1 申请相机权限
- 导入:
import AVFoundation
- 在项目的
Info.plist
文件里添加Privacy - Camera Usage Descriptio
描述申请使用相机权限。 - 查询相机权限:
AVCaptureDevice.authorizationStatus(for: .video)
- 权限类型:
AVAuthorizationStatus
notDetermined 未申请
restricted 受限制
denied 已拒绝
authorized 已授权
- 请求相机权限,系统弹出授权申请提示:
AVCaptureDevice.requestAccess(for: .video) { (status) in// handle request result
}
1.2 创建Scanner
- 获得设备:
guard let device = AVCaptureDevice.default(for: .video) else {print("device error")return
}
- 创建input:
let input: AVCaptureDeviceInput
do {input = try AVCaptureDeviceInput(device: device)
} catch {print("input error")return
}
if self.captureSession.canAddInput(input) {self.captureSession.addInput(input)
} else {print("session can't add input")return
}
- 创建 output:
let output = AVCaptureMetadataOutput()
if self.captureSession.canAddOutput(output) {// Tips: add output must before of set outputself.captureSession.addOutput(output)
} else {print("session can't add output")return
}// Set metadata identification type qr: QR code; Other: Barcode
// 设置扫描类型(qr:二维码,其他:条形码)
let hopeSupportTypes = [AVMetadataObject.ObjectType.qr,AVMetadataObject.ObjectType.ean13,AVMetadataObject.ObjectType.ean8,AVMetadataObject.ObjectType.pdf417]
var types: [AVMetadataObject.ObjectType] = []
for type in hopeSupportTypes {if output.availableMetadataObjectTypes.contains(type) {types.append(type)}
}
output.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
output.metadataObjectTypes = types
output.rectOfInterest = CGRect(x: 0, y: 0,width: self.view.bounds.size.width,height: self.view.bounds.size.height)
- 设置预览视图:
let previewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
previewLayer.frame = scanView.layer.bounds
previewLayer.videoGravity = .resizeAspectFill
scanView.layer.addSublayer(previewLayer)
1.3 开始扫描
Tips: 不能在主线程中扫描,否则会无法响应用户操作,导致卡死现象
DispatchQueue.global(qos: .userInitiated).async {self.captureSession.startRunning()
}
1.4 处理扫描结果
遵循 AVCaptureMetadataOutputObjectsDelegate
协议,实现扫描回调方法:
func metadataOutput(_ output: AVCaptureMetadataOutput,didOutput metadataObjects: [AVMetadataObject],from connection: AVCaptureConnection) {guard let metadataObject = metadataObjects.first else {captureSession.stopRunning()return}guard let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject else {print("as? AVMetadataMachineReadableCodeObject faliue")return}guard let stringValue = readableObject.stringValue else {print("stringValue faliue")return}AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))print("scan result: \\(stringValue)") // print resultcaptureSession.stopRunning()
}
2. 从相册里扫描
2.1 获取相册权限
- 导入:
import Photos
- 在项目的
Info.plist
文件里添加Privacy - Photo Library Usage Description
描述申请访问相册权限。 - 查询相机权限:
PHPhotoLibrary.authorizationStatus()
- 权限类型:
PHAuthorizationStatus
notDetermined 未申请
restricted 受限制
denied 已拒绝
authorized 已授权
limited 已授权有限库访问
- 请求相册权限,系统弹出授权申请提示:
PHPhotoLibrary.requestAuthorization { (status) in// handle request result
}
2.2 打开相册
Tips: 打开相册必须在主线程中执行
/// have photos permission
DispatchQueue.main.async {self.openPhotoLabrary()
}private func openPhotoLabrary() {let picker = UIImagePickerController()picker.title = "Photos"picker.delegate = selfpicker.allowsEditing = truepicker.sourceType = .photoLibrarypicker.navigationBar.barStyle = .defaultself.present(picker, animated: true, completion: nil)
}
2.3 获得选择结果
遵循 UIImagePickerControllerDelegate
和 UINavigationControllerDelegate
协议,并实现选中相片后触发的协议方法:
func imagePickerController(_ picker: UIImagePickerController,didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {dismiss(animated: true)guard let image = info[.originalImage] as? UIImage else {print("choose not image")return}parseBarCode(image: image)
}
2.4 解析相片中的二维码或条形码
导入:import Vision
/// parse qrCode or barCode
private func parseBarCode(image: UIImage) {guard let cgimg = image.cgImage else {return}let request = VNDetectBarcodesRequest { req, err inif let error = err {print("parseBarCode error: \\(error)")return}self.handleResults(req.results)}let handler = VNImageRequestHandler(cgImage: cgimg)do {try handler.perform([request])} catch {print("parseBarCode error: \\(error)")}
}private func handleResults(_ result: [VNObservation]?) {guard let results = result, results.count > 0 else {print("parseBarCode result is nil: \\(String(describing: result))")return}for result in results {self.handleResult(result)}
}private func handleResult(_ result: VNObservation) {guard let barcode = result as? VNBarcodeObservation,let value = barcode.payloadStringValue else {print("handleResult covert to string error: \\(result)")return}if barcode.symbology == .qr {print("二维码: \\(value)")} else {print("条形码: \\(value), \\(barcode.symbology.rawValue)")}
}
github demo
参考:
iOS16 Swift二维码/条形码扫描+相册获取识别