Create Image of SwiftUI layouts

CreateImageView.swift

import SwiftUI
import Charts

struct CreateImageView: View {
  @State var uiImage: UIImage?
  var body: some View {
    VStack {
      if let uiImage = uiImage {
        Image(uiImage: uiImage)
      }
    }
    .onAppear{
      do {
        let image = try createImage(AnyView(Page1()))
        uiImage = image
      } catch {
        print(error.localizedDescription)
      }
    }
  }
  
  struct Page1: View {
    let age = 22.0
    var body: some View {
      NavigationStack {
        VStack {
          List {
            Grid(alignment: .leading){
              GridRow {
                Text("Name")
                Text("Age")
              }
              .frame(width: 80)
              Divider()
                .gridCellUnsizedAxes(.horizontal)
              GridRow {
                Text("mbotsu")
                Text(String(format: "%d", Int(age)))
              }
              .frame(width: 80)
            }
          }
          .frame(width: 200, height: 120, alignment: .center)
          .scrollContentBackground(.hidden)
          .shadow(radius: 1)
          
          Chart {
            BarMark(
              xStart: .value("", 20),
              xEnd: .value("", 30)
            )
            .foregroundStyle(.blue)
            .cornerRadius(10)
            BarMark(
              xStart: .value("", age - 0.5),
              xEnd: .value("", age + 0.5)
            )
            .foregroundStyle(.cyan)
            PointMark(
              x: .value("", age)
            )
            .annotation(position: .overlay){
              Image(systemName: "checkmark.seal")
                .imageScale(.large)
                .symbolRenderingMode(.palette)
                .foregroundStyle(.black, .yellow)
                .symbolVariant(.fill)
            }
            .foregroundStyle(.green)
          }
          .chartYAxis {
            AxisMarks{}
          }
          .chartXAxis {
            AxisMarks(preset: .aligned){
              AxisValueLabel().font(.body)
            }
          }
          .chartXScale(domain: 20...30)
          .frame(width: 300, height: 100)
          Spacer()
        }
        .navigationTitle("hoge")
      }
    }
  }
}

func createImage(_ view: AnyView,
                 width:CGFloat=595.2,
                 height:CGFloat=841.8) throws -> UIImage {
  
  let rect = CGRect(x: 0, y: 0, width: width, height: height)
  
  guard let rootVC = (UIApplication.shared.connectedScenes.first as? UIWindowScene)?
    .windows.first?.rootViewController else {
    throw NSError(domain: "rootViewController NotFound", code: -1)
  }
  
  let size = CGSize(width: width, height: height)
  UIGraphicsBeginImageContextWithOptions(size, false, 0)
  UIGraphicsBeginImageContext(size)
  
  guard let context = UIGraphicsGetCurrentContext() else {
    throw NSError(domain: "Context failed", code: -1)
  }

  let vc = UIHostingController(rootView: view)
  vc.view.frame = rect
  rootVC.addChild(vc)
  rootVC.view.insertSubview(vc.view, at: 0)
  
  context.clear(rect)
  rootVC.view.layer.render(in: context)
  
  vc.removeFromParent()
  vc.view.removeFromSuperview()
  
  guard let image = UIGraphicsGetImageFromCurrentImageContext() else {
    throw NSError(domain: "Image context failed", code: -1)
  }

  UIGraphicsEndImageContext()
  
  return image
}

struct CreateImageView_Previews: PreviewProvider {
  static var previews: some View {
    CreateImageView()
  }
}

Preview Image