Rendering SwiftUI View to UIImage at a deeper navigation level

I need to render a SwiftUI View to an UIImage without displaying it for sharing purposes, but the solutions I found here are not working if I do the rendering in a View referred by a NavigationLink.

Here is a minimal example for reproducing my problem:

SampleView.swift (the one I need rendered as UIImage)

struct SampleView: View {
    var body: some View {
        Image(systemName: "globe").ignoresSafeArea()
    }
    
    func getImage() -> UIImage {
        let controller = UIHostingController(rootView: self)
        controller.view.bounds = CGRect(origin: .zero, size: CGSize(width: 100, height: 100))
        let format = UIGraphicsImageRendererFormat()
        format.scale = 1
        return UIGraphicsImageRenderer(size: controller.view.layer.frame.size, format: format).image { context in
            controller.view.drawHierarchy(in: controller.view.layer.bounds, afterScreenUpdates: true)
        }
    }
}

ContentView.swift

struct ContentView: View {
    var image: UIImage
    
    init() {
        self.image = SampleView().getImage()
    }
    
    var body: some View {
        NavigationView {
            VStack {
                Text("MainContentView")
                Image(uiImage: self.image) //working
                NavigationLink(
                    destination: SubContentView()
                ) {
                    Text("NavigationLink")
                } // end of navigationLink
            } // end of vstack
        } // end of navigationview
    }
}

SubContentView.swift

struct SubContentView: View {
    
    var image: UIImage
    
    init() {
        self.image = SampleView().getImage()
    }
    
    var body: some View {
        VStack {
            Text("SubContentView")
            Image(uiImage: self.image)
        }
    }
}

The SampleView will be rendered correctly at my ContentView, but is rendered to a blank image at my SubContentView.

Xcode is showing following error message on output

2023-08-04 23:46:48.901870+0200 ViewRenderToImageTest[9929:192715] [Snapshotting] View (0x156f0e140, _TtGC7SwiftUI14_UIHostingViewV21ViewRenderToImageTest10SampleView_) drawing with afterScreenUpdates:YES inside CoreAnimation commit is not supported.

How to render my SampleView correctly to an image from the SubContentView?

From the log message, it seems like at the time that you call getImage, it is in the middle of a Core Animation transaction (in order to show the SubContentView), and that makes it unable to draw the view. There was no transaction when showing the ContentView, probably because it is the root.

Therefore, I tried putting the getImage call inside DispatchQueue.main.async. The idea is to allow the main queue to finish the transaction, and only then draw the view. This worked.

struct SubContentView: View {
    
    @State var image: UIImage?
    
    var body: some View {
        VStack {
            Text("SubContentView")
            if let image {
                Image(uiImage: image)
            }
        }.onAppear {
            DispatchQueue.main.async {
                image = SampleView().getImage()
            }
        }
    }
}