Ios AVFoundation、数据矩阵、Swift 4
啊。我与Swift 4 AVFoundation变革的斗争仍在继续 我有一个数据矩阵“QR”代码,我正在尝试读取 在Swift 3编译时,它读起来很好,但在Swift 4对代码进行更改时,它不会被拾取 还要注意,苹果提供的示例应该与Swift 4一起使用,但也没有读取DataMatrix代码 当我打印出可用类型时,数据矩阵可用Ios AVFoundation、数据矩阵、Swift 4,ios,avfoundation,barcode-scanner,swift4,Ios,Avfoundation,Barcode Scanner,Swift4,啊。我与Swift 4 AVFoundation变革的斗争仍在继续 我有一个数据矩阵“QR”代码,我正在尝试读取 在Swift 3编译时,它读起来很好,但在Swift 4对代码进行更改时,它不会被拾取 还要注意,苹果提供的示例应该与Swift 4一起使用,但也没有读取DataMatrix代码 当我打印出可用类型时,数据矩阵可用 print("types available:\n \(metadataOutput.availableMetadataObjectTypes)") 收益率: type
print("types available:\n \(metadataOutput.availableMetadataObjectTypes)")
收益率:
types available:
[__ObjC.AVMetadataObject.ObjectType(_rawValue: face), ...
__ObjC.AVMetadataObject.ObjectType(_rawValue: org.iso.DataMatrix), ...
但是,当我运行代码时,从未调用didOutput metadataObjects:。但是,它确实会被其他类型调用
另外,显式添加类型:
metadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.dataMatrix]
没有什么不同
有人有在Swift 4中扫描数据矩阵的经验吗
代码:
import UIKit
import AVFoundation
class ViewController: UIViewController,AVCaptureMetadataOutputObjectsDelegate {
var videoCaptureDevice: AVCaptureDevice = AVCaptureDevice.default(for: AVMediaType.video)!
var device = AVCaptureDevice.default(for: AVMediaType.video)
var output = AVCaptureMetadataOutput()
var previewLayer: AVCaptureVideoPreviewLayer?
var captureSession = AVCaptureSession()
var code: String?
var scannedCode = UILabel()
override func viewDidLoad() {
super.viewDidLoad()
self.setupCamera()
self.addLabelForDisplayingCode()
}
private func setupCamera() {
let input = try? AVCaptureDeviceInput(device: videoCaptureDevice)
if self.captureSession.canAddInput(input!) {
self.captureSession.addInput(input!)
}
self.previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
if let videoPreviewLayer = self.previewLayer {
videoPreviewLayer.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer.frame = self.view.bounds
view.layer.addSublayer(videoPreviewLayer)
}
let metadataOutput = AVCaptureMetadataOutput()
if self.captureSession.canAddOutput(metadataOutput) {
self.captureSession.addOutput(metadataOutput)
metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
print("types available:\n \(metadataOutput.availableMetadataObjectTypes)")
metadataOutput.metadataObjectTypes = metadataOutput.availableMetadataObjectTypes
// metadataOutput.metadataObjectTypes = [AVMetadataObject.ObjectType.dataMatrix]
} else {
print("Could not add metadata output")
}
}
private func addLabelForDisplayingCode() {
view.addSubview(scannedCode)
scannedCode.translatesAutoresizingMaskIntoConstraints = false
scannedCode.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20.0).isActive = true
scannedCode.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20.0).isActive = true
scannedCode.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant: -20.0).isActive = true
scannedCode.heightAnchor.constraint(equalToConstant: 50).isActive = true
scannedCode.font = UIFont.preferredFont(forTextStyle: .title2)
scannedCode.backgroundColor = UIColor.black.withAlphaComponent(0.5)
scannedCode.textAlignment = .center
scannedCode.textColor = UIColor.white
scannedCode.text = "Scanning...."
}
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 metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
print(metadataObjects)
for metadata in metadataObjects {
let readableObject = metadata as! AVMetadataMachineReadableCodeObject
let code = readableObject.stringValue
scannedCode.text = code
}
}
}
非常感谢。您必须确保连接未镜像。 数据矩阵需要以原始格式读取
您是否在plist中添加了
NSCameraUsageDescription
?好主意。但我已经有了。但这是一个非常典型的错误——你问得对!你想出来了吗?没有,但安迪·雅各布斯想出来了。见下文