在iOS 14+上将SwiftUI视图转换为UIImage

import SwiftUI

class SwiftUIContainerView: UIView {
    private var hostingController: UIHostingController<AnyView>?

    init(rootView: AnyView) {
        super.init(frame: .zero)
        hostingController = UIHostingController(rootView: rootView)
        addSubview(hostingController!.view)
        hostingController!.view.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            hostingController!.view.leadingAnchor.constraint(equalTo: leadingAnchor),
            hostingController!.view.trailingAnchor.constraint(equalTo: trailingAnchor),
            hostingController!.view.topAnchor.constraint(equalTo: topAnchor),
            hostingController!.view.bottomAnchor.constraint(equalTo: bottomAnchor)
        ])
    }

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

    func snapshot() -> UIImage? {
        UIGraphicsBeginImageContextWithOptions(bounds.size, false, 0)
        defer { UIGraphicsEndImageContext() }
        drawHierarchy(in: bounds, afterScreenUpdates: true)
        return UIGraphicsGetImageFromCurrentImageContext()
    }
}

import SwiftUI

// 创建一个SwiftUI视图
struct ContentView: View {
    var body: some View {
        Text("Hello, SwiftUI!")
            .font(.largeTitle)
            .foregroundColor(.blue)
    }
}

// 在需要的地方将SwiftUI视图转换为UIImage
let swiftUIView = ContentView().eraseToAnyView()
let containerView = SwiftUIContainerView(rootView: swiftUIView)
let image = containerView.snapshot()