Introduction
Hello,
As part of our ongoing migration to SwiftUI, we are currently managing navigation using UIKit. Our SwiftUI views are embedded in UIHostingController instances and pushed or presented via UINavigationController.
We’ve encountered an issue that causes either a UI glitch on iOS 18 or a crash on iOS 17 when using the .refreshable modifier in a SwiftUI view that is added to a UINavigationController via setViewControllers(_:animated:).
To reproduce the issue, we’re using the following simple SwiftUI view:
struct TestView: View {
var body: some View {
List {
ForEach(0...100, id: \.self) {
Text("Number: \($0)")
}
}
.refreshable {
// No action needed — the presence of this modifier alone triggers the issue
}
}
}
Problematic Scenario
The following code causes the issue:
class ViewController: UIViewController {
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let initialNav = self.navigationController
let hostingController = UIHostingController(rootView: TestView())
let newNav = UINavigationController()
// This causes a freeze (iOS 18) or crash (iOS 17)
newNav.setViewControllers([hostingController], animated: true)
initialNav?.present(newNav, animated: true)
}
}
After presenting the navigation controller, our app is freezing on iOS 18 or crashing on iOS 17.
Working scenario
When using pushViewController(_:animated:), the issue does not occur:
class ViewController: UIViewController {
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
let initialNav = self.navigationController
let hostingController = UIHostingController(rootView: TestView())
let newNav = UINavigationController()
// This works without issue
newNav.pushViewController(hostingController, animated: true)
initialNav?.present(newNav, animated: true)
}
}
Conclusion
We would like to better understand the root cause of this behavior. While using pushViewController is a viable workaround, there are scenarios where we must rely on setViewControllers, and currently, that approach breaks the experience or crashes the app.
Is this a known issue, or are we missing something about how UIHostingController interacts with .refreshable in this context?
Thanks for your time — we look forward to any insights you can share.
