如何使用AVCaptureVideoPreviewLayer从相机应用程序实现2倍缩放

import AVFoundation

let captureSession = AVCaptureSession()
guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
guard let input = try? AVCaptureDeviceInput(device: captureDevice) else { return }
captureSession.addInput(input)

let videoOutput = AVCaptureVideoDataOutput()
videoOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as String: kCVPixelFormatType_32BGRA]
videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue.global(qos: .default))
captureSession.addOutput(videoOutput)

let previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
previewLayer.videoGravity = .resizeAspectFill
previewLayer.frame = view.bounds
view.layer.addSublayer(previewLayer)

captureSession.startRunning()

func zoom(scale: CGFloat) {
    guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
    do {
        try captureDevice.lockForConfiguration()
        defer { captureDevice.unlockForConfiguration() }
        captureDevice.videoZoomFactor = scale
    } catch {
        print("Zoom failed: \(error.localizedDescription)")
    }
}

zoom(scale: 2.0)