将CameraView中的图像与覆盖进行组合。(Swift 3)？

import AVFoundation
import UIKit

class CameraView: UIView {
    private var previewLayer: AVCaptureVideoPreviewLayer?
    private var overlayView: UIView?
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        setupCamera()
        setupOverlay()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupCamera()
        setupOverlay()
    }
    
    private func setupCamera() {
        let captureSession = AVCaptureSession()
        guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
        
        do {
            let input = try AVCaptureDeviceInput(device: captureDevice)
            captureSession.addInput(input)
        } catch {
            print("Error setting up camera input: \(error.localizedDescription)")
            return
        }
        
        let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        previewLayer.videoGravity = .resizeAspectFill
        previewLayer.frame = bounds
        layer.addSublayer(previewLayer)
        
        captureSession.startRunning()
        self.previewLayer = previewLayer
    }
    
    private func setupOverlay() {
        let overlayView = UIView(frame: bounds)
        overlayView.backgroundColor = UIColor.clear
        // 添加覆盖视图的其他内容，例如标签、按钮等
        addSubview(overlayView)
        
        self.overlayView = overlayView
    }
}

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        let cameraView = CameraView(frame: view.bounds)
        view.addSubview(cameraView)
    }
}