我正在遵循https://developer.apple.com/tutorials/swiftui/interfacing-with-uikit，并尝试将我的页面视图添加到UIHostingController数组中。当我这样做时一切都正常：
PageView(pages: [Text("hi"), Text("hello!")])
当视图类型不同时，我收到了"Failed to produce diagnostic for expression; please file a bug report"的错误提示：
PageView(pages: [Text("hi"), SomeOtherView()])
这是我的代码：
页面控制器（PageViewController）
struct PageViewController<Page: View>: UIViewControllerRepresentable {
var pages: [Page]
@Binding var currentPage: Int
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> UIPageViewController {
let pageViewController = UIPageViewController(
transitionStyle: .scroll,
navigationOrientation: .horizontal
)
pageViewController.dataSource = context.coordinator
pageViewController.delegate = context.coordinator
return pageViewController
}
func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
pageViewController.setViewControllers(
[context.coordinator.controllers[currentPage]], direction: .forward, animated: true)
}
class Coordinator: NSObject, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var parent: PageViewController
var controllers = [UIViewController]()
init(_ pageViewController: PageViewController) {
parent = pageViewController
controllers = parent.pages.map { UIHostingController(rootView: $0.navigationBarHidden(true)) }
for viewController in controllers {
viewController.view.backgroundColor = .clear
}
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let index = controllers.firstIndex(of: viewController) else { return nil }
//swiping back on page 0
if index == 0 {
return nil
}
return controllers[index - 1]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let index = controllers.firstIndex(of: viewController) else { return nil }
//swiping forward on last page
if index + 1 == controllers.count {
return nil
}
return controllers[index + 1]
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed,
let visibleViewController = pageViewController.viewControllers?.first,
let index = controllers.firstIndex(of: visibleViewController) {
parent.currentPage = index
}
}
}
}
页面浏览量
struct PageView<Page: View>: View {
var pages: [Page]
@State private var currentPage = 0
var body: some View {
PageViewController(pages: pages, currentPage: $currentPage)
Text("Current page = \(currentPage)")
}
}