如何通过XCode在iOS应用中实现摄像头功能

var captureSession: AVCaptureSession?
var previewLayer: AVCaptureVideoPreviewLayer?

func setupCaptureSession() {
    captureSession = AVCaptureSession()
    
    guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
    
    do {
        let input = try AVCaptureDeviceInput(device: captureDevice)
        captureSession?.addInput(input)
    } catch {
        print(error.localizedDescription)
        return
    }
    
    let output = AVCaptureVideoDataOutput()
    output.setSampleBufferDelegate(self, queue: DispatchQueue(label: "videoQueue"))
    captureSession?.addOutput(output)
    
    previewLayer = AVCaptureVideoPreviewLayer(session: captureSession!)
    previewLayer?.videoGravity = .resizeAspectFill
    previewLayer?.frame = view.frame
    view.layer.insertSublayer(previewLayer!, at: 0)
    
    captureSession?.startRunning()
}

override func viewDidLoad() {
    super.viewDidLoad()
    setupCaptureSession()
}

extension ViewController: AVCaptureVideoDataOutputSampleBufferDelegate {
    func captureOutput(_ output: AVCaptureOutput, didOutput sampleBuffer: CMSampleBuffer, from connection: AVCaptureConnection) {
        // 在这里处理视频数据
    }
}