自定義相機一

class FaceCameraVC: UIViewController, AVCapturePhotoCaptureDelegate {

    private let captureSession = AVCaptureSession()
    private var previewLayer: AVCaptureVideoPreviewLayer!
    private var capturePhotoOutput: AVCapturePhotoOutput!
    
    private let bgView = UIView()
    private let plaseLab = UILabel()
    
    private let closeBtn = UIButton(type: .custom)
    private let cancelBtn = UIButton(type: .custom)
    private let confirmBtn = UIButton(type: .custom)
    private let photographBtn = UIButton(type: .custom)
    
    typealias FacePhotoFinishBlock = (_ image: UIImage?)->Void
    var facePhotoFinishBlock: FacePhotoFinishBlock?
    

    override func viewDidLoad() {
        super.viewDidLoad()
        
        setupCamera()
        
        view.addSubview(bgView)
        bgView.backgroundColor = .black.withAlphaComponent(0.6)
        bgView.snp.makeConstraints { make in
            make.edges.equalToSuperview()
        }
        
        view.addSubview(closeBtn)
        closeBtn.backgroundColor = .red
        closeBtn.snp.makeConstraints { make in
            make.left.equalTo(20)
            make.size.equalTo(CGSizeMake(25, 25))
            make.top.equalTo(view.snp.topMargin).offset(20)
        }
        
        view.addSubview(photographBtn)
        photographBtn.backgroundColor = .blue
        photographBtn.snp.makeConstraints { make in
            make.centerX.equalToSuperview()
            make.size.equalTo(CGSize(width: 64, height: 64))
            make.bottom.equalTo(view.snp.bottomMargin).offset(-15)
        }
        
        view.addSubview(cancelBtn)
        view.addSubview(confirmBtn)
        
        cancelBtn.backgroundColor = .green
        confirmBtn.backgroundColor = .brown
        
        cancelBtn.snp.makeConstraints { make in
            make.left.equalTo(88)
            make.centerY.equalTo(photographBtn)
            make.size.equalTo(CGSize(width: 52, height: 52))
        }
        
        confirmBtn.snp.makeConstraints { make in
            make.right.equalTo(-88)
            make.centerY.equalTo(photographBtn)
            make.size.equalTo(CGSize(width: 52, height: 52))
        }
        
        view.addSubview(plaseLab)
        plaseLab.numberOfLines = 0
        plaseLab.textColor = .white
        plaseLab.textAlignment = .center
        plaseLab.font = .systemFont(ofSize: 14)
        plaseLab.text = "Please face your phone, and take a selfie"
        
        plaseLab.snp.makeConstraints { make in
            make.centerX.equalToSuperview()
            make.top.equalTo(closeBtn.snp.bottom).offset(60)
        }
        
        cancelBtn.isHidden = true
        confirmBtn.isHidden = true
        
        closeBtn.addTarget(self, action: #selector(cancelBtnClick(_:)), for: .touchUpInside)
        cancelBtn.addTarget(self, action: #selector(cancelBtnClick(_:)), for: .touchUpInside)
        confirmBtn.addTarget(self, action: #selector(confirmBtnClick(_:)), for: .touchUpInside)
        photographBtn.addTarget(self, action: #selector(photographBtnClick(_:)), for: .touchUpInside)
            
    }
    
    @objc func cancelBtnClick(_ btn: UIButton) {
        
        facePhotoFinishBlock?(nil)
        self.navigationController?.popViewController(animated: true)
    }
    
    @objc func confirmBtnClick(_ btn: UIButton) {
        
        
    }
    
    @objc func photographBtnClick(_ btn: UIButton) {
        
        let settings = AVCapturePhotoSettings()
        capturePhotoOutput.capturePhoto(with: settings, delegate: self)
        
        btn.isHidden = true
        cancelBtn.isHidden = !btn.isHidden
        confirmBtn.isHidden = !btn.isHidden
    }
    
    func setupCamera() {
        
        captureSession.sessionPreset = .photo
        
        guard let frontCamera = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .front) else {
            print("Unable to access front camera")
            return
        }
        
        do {
            let input = try AVCaptureDeviceInput(device: frontCamera)
            captureSession.addInput(input)
            capturePhotoOutput = AVCapturePhotoOutput()
            captureSession.addOutput(capturePhotoOutput)
        } catch {
            print(error.localizedDescription)
        }
        
        previewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
        previewLayer.videoGravity = .resizeAspectFill
        previewLayer.frame = view.layer.bounds
        view.layer.addSublayer(previewLayer)
        
        captureSession.startRunning()
    }
    
    func photoOutput(_ output: AVCapturePhotoOutput, didFinishProcessingPhoto photo: AVCapturePhoto, error: Error?) {
        
        if let error = error {
            print("Error capturing photo: \(error.localizedDescription)")
            return
        }

        guard let imageData = photo.fileDataRepresentation() else {
            print("Unable to get photo data")
            return
        }

        var capturedImage = UIImage(data: imageData)

        if let cgImage = capturedImage?.cgImage {
            capturedImage = UIImage(cgImage: cgImage, scale: capturedImage?.scale ?? 1.0, orientation: .leftMirrored)
        }
        
        captureSession.stopRunning()
    }
}