<分区>
它只显示相机的输出，但没有任何反应。我不知道有什么问题。
我的代码是:
class QRScannerController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
var captureSession:AVCaptureSession?
var videoPreviewLayer:AVCaptureVideoPreviewLayer?
var qrCodeFrameView:UIView?
let supportedCodeTypes = [AVMetadataObject.ObjectType.qr]
var resultString = ""
override func viewDidLoad() {
super.viewDidLoad()
guard let captureDevice = AVCaptureDevice.default(for: AVMediaType.video) else {return}
do {
let input = try AVCaptureDeviceInput(device: captureDevice)
captureSession = AVCaptureSession()
captureSession?.addInput(input)
let captureMetadataOutput = AVCaptureMetadataOutput()
captureSession?.addOutput(captureMetadataOutput)
captureMetadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
captureMetadataOutput.metadataObjectTypes = supportedCodeTypes
videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
videoPreviewLayer?.videoGravity = AVLayerVideoGravity.resizeAspectFill
videoPreviewLayer?.frame = view.layer.bounds
view.layer.addSublayer(videoPreviewLayer!)
captureSession?.startRunning()
qrCodeFrameView = UIView()
if let qrCodeFrameView = qrCodeFrameView {
qrCodeFrameView.layer.borderColor = UIColor.green.cgColor
qrCodeFrameView.layer.borderWidth = 2
self.view.addSubview(qrCodeFrameView)
self.view.bringSubview(toFront: qrCodeFrameView)
}
captureSession?.startRunning()
} catch {
// If any error occurs, simply print it out and don't continue any more.
print(error)
return
}
}
委托(delegate):
// MARK: - AVCaptureMetadataOutputObjectsDelegate Methods
func metadataOutput(captureOutput: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
if metadataObjects.count == 0 {
qrCodeFrameView?.frame = CGRect.zero
//messageLabel.text = "No QR/barcode is detected"
print("No QR/barcode is detected")
return
}
let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject
if supportedCodeTypes.contains(metadataObj.type) {
let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
qrCodeFrameView?.frame = barCodeObject!.bounds
if metadataObj.stringValue != nil {
print(metadataObj.stringValue as Any)
}
}
}
我尝试通过放置断点进行调试，但是在委托(delegate)方法中没有触发任何断点。
有人知道为什么会这样吗？
谢谢!