I am developing SDK and swizzling viewDidAppear. I have a customer who implements a custom TabBar Navigation where VC's are added to the hierarchy on the first load, and then, he changes the opacity to the currently displayed tab so the next time the user sees the tab - viewDidAppear isn't called, so my code isn't called. I'm attaching a sample project which reproduces that. Is there any way to trigger ViewDidAppear intentionally? If yes, what can be the side effect of doing that? Do I have any other alternative in this case? @main struct DemoCustomTabViewApp: App { @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate var body: some Scene { WindowGroup { TabBarRouterView() } } } import UIKit // MARK: - TabBarItem (unchanged) enum TabBarItem: Identifiable, CaseIterable { case home, search, profile var id: Self { self } var title: String { switch self { case .home: return "Home" case .search: return "Search" case .profile: return "Profile" } } var icon: String { switch self { case .home: return "house" case .search: return "magnifyingglass" case .profile: return "person" } } } // MARK: - NavigationControllerView struct NavigationControllerView: UIViewControllerRepresentable { var rootViewController: UIViewController func makeUIViewController(context: Context) -> UINavigationController { let navigationController = UINavigationController(rootViewController: rootViewController) return navigationController } func updateUIViewController(_ uiViewController: UINavigationController, context: Context) {} } // MARK: - TabBarRouterViewModel class TabBarRouterViewModel: ObservableObject { @Published var currentTab: TabBarItem = .home @Published var cachedViews: [TabBarItem: AnyView] = [:] let tabs: [TabBarItem] = TabBarItem.allCases func switchTab(to tab: TabBarItem) { currentTab = tab } func createView(for tab: TabBarItem) -> AnyView { if let cachedView = cachedViews[tab] { return cachedView } let rootViewController: UIViewController switch tab { case .home: rootViewController = UIHostingController(rootView: Text("Home View")) case .search: rootViewController = UIHostingController(rootView: Text("Search View")) case .profile: rootViewController = UIHostingController(rootView: Text("Profile View")) } let navigationView = NavigationControllerView(rootViewController: rootViewController) let anyView = AnyView(navigationView) cachedViews[tab] = anyView return anyView } } // MARK: - CustomTabBarView (unchanged) struct CustomTabBarView: View { let tabs: [TabBarItem] @Binding var selectedTab: TabBarItem let onTap: (TabBarItem) -> Void var body: some View { HStack { ForEach(tabs) { tab in Spacer() VStack { Image(systemName: tab.icon) .font(.system(size: 24)) Text(tab.title) .font(.caption) } .foregroundColor(selectedTab == tab ? .blue : .gray) .onTapGesture { onTap(tab) } Spacer() } } .frame(height: 60) .background(Color.white) .shadow(radius: 2) } } // MARK: - TabBarRouterView struct TabBarRouterView: View { @StateObject private var viewModel = TabBarRouterViewModel() var body: some View { VStack(spacing: .zero) { contentView CustomTabBarView( tabs: viewModel.tabs, selectedTab: $viewModel.currentTab, onTap: viewModel.switchTab ) } .edgesIgnoringSafeArea(.bottom) } private var contentView: some View { ZStack { ForEach(viewModel.tabs) { tab in viewModel.createView(for: tab) .opacity(viewModel.currentTab == tab ? 1.0 : 0.0) } } } }