Swift3：我想读取和计数二维码

Posted 2023-03-14

【中文标题】Swift3：我想读取和计数二维码

【英文标题】：Swift3: I would like to function read and count QR code

【发布时间】：2017-08-28 02:45:15

【问题描述】：

我正在构建一个二维码阅读器应用。我写了一个函数来读取和计算二维码。我可以显示动态按钮标题的计数；但是，二维码的值不是像1、2、3那样计算的。显示自然的二维码值。

我的视图控制器：

class LentScanViewController: QRScannerViewController 

var device_name = ""
var countNum = 0

@IBOutlet weak var LentButton: UIButton!
@IBAction func lentButton(_ sender: Any) 
    performSegue(withIdentifier: "toLentTable",sender: device_name)

override func viewDidLoad() 
    super.viewDidLoad()


func captureOutput(_ captureOutput: AVCaptureOutput!, didOutputMetadataObjects metadataObjects: [Any]!, from connection: AVCaptureConnection!) 


    if metadataObjects == nil || metadataObjects.count == 0 
        qrCodeFrameView?.frame = CGRect.zero
        return
    

    let metadataObj = metadataObjects[0] as! AVMetadataMachineReadableCodeObject

    if metadataObj.type == AVMetadataObjectTypeQRCode 

        let barCodeObject = videoPreviewLayer?.transformedMetadataObject(for: metadataObj)
        qrCodeFrameView?.frame = barCodeObject!.bounds

        if metadataObj.stringValue != nil 
            device_name = metadataObj.stringValue

            countNum = countNum + 1
            LentButton.setTitle(String(countNum) + "Lent", for:[])
        
    

【参考方案1】：

请尝试：

var qrCodes:[String] = [] // declare it as member variable in the class

然后调用

if metadataObj.stringValue != nil 
    let device_name = metadataObj.stringValue
    if !qrCodes.contains(device_name!) 
        qrCodes.append(device_name!)
    
    countNum = countNum + 1
    messageLabel.text = String(countNum) + "Lent"

【讨论】：

谢谢。但此代码是显示 metadataObj 值。我想如果扫描一个二维码显示 1. 再扫描一个显示 2.

就像这个视频youtube.com/watch?v=zKMyp17Squ8&feature=youtu.be

编辑了答案。请检查。