传递没有文本字段的数据

Question

我目前在尝试将数据从QR码扫描仪控制器传递到视图控制器时遇到问题。这样做的原因是因为我在一个事件中会有30多个Qr代码，并且所有这些代码都将转换到相同的视图控制器但具有不同的标签/数据。

查看控制器

var myString:String = ""
@IBOutlet var label: UILabel!

override func viewDidLoad() {
    super.viewDidLoad()

    label?.text = myString

}

QR扫描仪控制器

func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let secondController = segue.destination as! Sample3Controller
  if segue.identifier == "Segue1"
       {
           secondController.myString = "Welcome to Booth 1"
       }
  else if segue.identifier == "Segue2"
       {
           secondController.myString = "Welcome to Booth 2"
       }
     }
            if metadataObj.stringValue == "Booth 1" //if qr code text is "Booth1"
            {
                captureSession?.stopRunning()
                self.performSegue(withIdentifier: "Segue1", sender: self)
            }
            else if metadataObj.stringValue == "Booth 2" // if qr code text is "Booth2"
            {
                captureSession?.stopRunning()
                self.performSegue(withIdentifier: "Segue2", sender: self)
            }