UIViewRepresentable视图的AVFoundation旋转

Question

我使用CameraPreview (UIViewRepresentable)作为UIKit和SwiftUI之间的桥梁。CameraPreview使用CameraModel进行配置，并使用AVCaptureVideoPreviewLayer。CameraModel正在配置AVCaptureSession和AVCaptureDeviceInput。除了我尝试在iPad上旋转设备之外，一切都很好。CameraPreview没有正确地旋转，并且使用以前旋转的输入。(下图)我可以检查SwiftUI (基于本文)中正在旋转的设备，但是我不知道如何重新配置CameraPreview和AVCaptureVideoPreviewLayer的旋转。知道在我发现设备被旋转后如何在UIKit中触发布局更新吗？

代码如下：

struct CameraView: View {
    @StateObject var camera = CameraModel()

    var body: some View {
            CameraPreview(camera: camera)
                .ignoresSafeArea(.all, edges: .all)
     }
}

struct CameraPreview: UIViewRepresentable {
    @ObservedObject var camera: CameraModel
    
    func makeUIView(context: Context) -> UIView {
        let view = UIView(frame: UIScreen.main.bounds)
        camera.preview = AVCaptureVideoPreviewLayer(session: camera.session)
        camera.preview.frame = view.frame
        
        //your own properies
        camera.preview.videoGravity = .resizeAspectFill
        view.layer.addSublayer(camera.preview)
        
        //starting session
        camera.session.startRunning()
        return view
    }
    
    func updateUIView(_ uiView: UIViewType, context: Context) { }
}

class CameraModel: NSObject, ObservableObject, AVCapturePhotoCaptureDelegate {
    @Published var session = AVCaptureSession()
    @Published var preview: AVCaptureVideoPreviewLayer!
    @Published var output = AVCapturePhotoOutput()

    func setUp() {
        do {
            self.session.beginConfiguration()
            let device = AVCaptureDevice.default(for: .video)
            let input = try AVCaptureDeviceInput(device:device!)
            if self.session.canAddInput(input) {
                self.session.addInput(input)
            } 
            if self.session.canAddOutput(self.output) {
                self.session.addOutput(self.output)
            } 
            self.session.commitConfiguration()
            
        }catch {
            print(error.localizedDescription)
        }
    }
}

​

​

Answer 1

我通过以下方式解决了这一问题：

1. 使预览框架适应bounds而不是frame。
2. 当我在某些superview View上检测到设备方向的变化时，我改变了deviceRotation变量的值，这会自动触发updateUIView函数。 struct CameraPreview: UIViewRepresentable { @ObservedObject var摄像机: CameraModel var deviceRotation: UIDeviceOrientation func makeUIView(上下文:上下文) -> UIView { let view = UIView(frame: UIScreen.main.bounds) camera.preview =AVCaptureVideoPreviewLayer(会话: camera.session) camera.preview.frame = view.bounds //您自己的属性camera.preview.videoGravity = .resizeAspectFill view.layer.addSublayer(view.bounds)//启动会话()返回updateUIView(_ uiView: UIViewType，上下文:上下文){ let view =UIView(框架: UIScreen.main.bounds) camera.preview.frame = view.bounds }
3. 手动在AVCaptureVideoOrientation上设置AVCaptureConnection以纠正设备方向。每当我检测到方向变化时，我都会这样做： previewConnection.videoPreviewLayer?.connection?.videoOrientation = orientation.videoOrientation