相机预览上的SwiftUI位置叠加

Question

我正在尝试将使用类似目标的叠加层添加到使用在某些设备上拍摄肖像，在其他设备上拍摄风景。我可以手动设置坐标，但是无法获得相机预览框架的正确坐标。

这是一个SwiftUI应用程序，所以我正在使用UIViewControllerRepresentable。这就是我所拥有的，显然，目标圈子是当设备和/或方向改变时，总是错误的。我似乎无法捕捉相机预览所在的模式视图的框架。我愿意成为能够在模态视图上指定摄像机预览的框架和位置。

struct CaptureImageView: View {
    @Binding var isShown: Bool
    @Binding var image: Image?
    @Binding var newUIImage: UIImage?
    @Binding var showSaveButton: Bool

    func makeCoordinator() -> Coordinator {
        return Coordinator(isShown: $isShown, image: $newUIImage, showSaveButton: $showSaveButton)
    }
}

extension CaptureImageView: UIViewControllerRepresentable {

    func makeUIViewController(context: UIViewControllerRepresentableContext<CaptureImageView>) -> UIImagePickerController {

        let vc = UIImagePickerController()

        if UIImagePickerController.isSourceTypeAvailable(UIImagePickerController.SourceType.camera) {
            vc.sourceType = .camera
            vc.allowsEditing = true
            vc.delegate = context.coordinator

            let screenSize: CGRect = UIScreen.main.bounds
            let screenWidth = screenSize.width
            let screenHeight = screenSize.height

            vc.cameraOverlayView = CircleView(frame: CGRect(x: (screenWidth / 2) - 50, y: (screenWidth / 2) + 25, width: 100, height: 100))

            return vc
        }
        return UIImagePickerController()
    }

    func updateUIViewController(_ uiViewController: UIImagePickerController, context: UIViewControllerRepresentableContext<CaptureImageView>) {
    }
}

这里是想法-但目标始终需要居中：

和目标文件：

class CircleView: UIView {

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.backgroundColor = UIColor.clear
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func draw(_ rect: CGRect) {
        if let context = UIGraphicsGetCurrentContext() {
            context.setLineWidth(3.0)
            UIColor.red.set()

            let center = CGPoint(x: frame.size.width / 2, y: frame.size.height / 2)
            let radius = (frame.size.width - 10) / 2

            context.addArc(center: center, radius: radius, startAngle: 0.0, endAngle: .pi * 2.0, clockwise: true)
            context.strokePath()
        }
    }
}

任何指导将不胜感激。 Xcode版本11.3.1（11C504）

Answer 1

虽然我仍然想找到获取相机框架的方法的答案-我的目标主要可以通过在VStack中像这样创建圆形视图来实现：

if showCaptureImageView {
    ZStack {
        CaptureImageView(isShown: $showCaptureImageView, image: $myImage, newUIImage: $newUIImage, showSaveButton: $showSaveButton)

        Circle()
            .stroke(Color.red, style: StrokeStyle(lineWidth: 10 ))
            .frame(width: 100, height: 100)
            .offset(CGSize(width: 0, height: -50.0))
    }
}//if show