如何在扫描二维码后转到新的viewcontroller？

import AVFoundation

class ScanViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate {
    var captureSession: AVCaptureSession!
    var previewLayer: AVCaptureVideoPreviewLayer!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 初始化扫描会话
        captureSession = AVCaptureSession()
        
        // 获取设备的摄像头
        guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else { return }
        
        // 创建输入流
        guard let videoInput = try? AVCaptureDeviceInput(device: videoCaptureDevice) else { return }
        
        // 将输入流添加到会话
        if captureSession.canAddInput(videoInput) {
            captureSession.addInput(videoInput)
        } else {
            // 处理无法添加输入流的情况
            return
        }
        
        // 创建输出流
        let metadataOutput = AVCaptureMetadataOutput()
        
        // 将输出流添加到会话
        if captureSession.canAddOutput(metadataOutput) {
            captureSession.addOutput(metadataOutput)
            
            // 设置输出流的代理和扫描类型
            metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
            metadataOutput.metadataObjectTypes = [.qr]
        } else {
            // 处理无法添加输出流的情况
            return
        }
        
        // 创建预览图层
        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        previewLayer.frame = view.layer.bounds
        previewLayer.videoGravity = .resizeAspectFill
        
        // 将预览图层添加到视图层级
        view.layer.addSublayer(previewLayer)
        
        // 启动扫描会话
        captureSession.startRunning()
    }
    
    // 扫描结果回调方法
    func metadataOutput(_ output: AVCaptureMetadataOutput, didOutput metadataObjects: [AVMetadataObject], from connection: AVCaptureConnection) {
        // 停止扫描会话
        captureSession.stopRunning()
        
        // 检查是否有扫描结果
        if let metadataObject = metadataObjects.first as? AVMetadataMachineReadableCodeObject,
           let qrCodeString = metadataObject.stringValue {
            // 创建目标ViewController的实例
            let targetViewController = TargetViewController()
            
            // 将扫描结果传递给目标ViewController
            targetViewController.qrCodeString = qrCodeString
            
            // 跳转到目标ViewController
            navigationController?.pushViewController(targetViewController, animated: true)
        }
    }
}

class TargetViewController: UIViewController {
    var qrCodeString: String?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 在目标ViewController中展示扫描结果
        if let qrCodeString = qrCodeString {
            // 处理扫描结果
        }
    }
}