Hi
I refactored my NavigationBarView and was able to me more "SwiftUI" like in the implementation. Hope this helps:
import SwiftUI
extension View {
func onWillDisappear(_ perform: @escaping () -> Void) -> some View {
modifier(ViewWillDisappearModifier(callback: perform))
}
func onWillAppear(_ perform: @escaping () -> Void) -> some View {
modifier(ViewWillAppearModifier(callback: perform))
}
}
struct ViewWillDisappearModifier: ViewModifier {
let callback: () -> Void
func body(content: Content) -> some View {
content.background(UIViewControllerResponder(viewWillDisappear: callback))
}
}
struct ViewWillAppearModifier: ViewModifier {
let callback: () -> Void
func body(content: Content) -> some View {
content.background(UIViewControllerResponder(viewWillAppear: callback))
}
}
private struct UIViewControllerResponder: UIViewControllerRepresentable {
/// Notifies the view controller that its view is about to be added to a view hierarchy.
var viewWillAppear: (() -> Void)? = nil
/// Notifies the view controller that its view is about to be removed from a view hierarchy.
var viewWillDisappear: (() -> Void)? = nil
private let controller = ViewController()
func makeUIViewController(context: UIViewControllerRepresentableContext<UIViewControllerResponder>) -> UIViewController {
if let viewWillAppear = viewWillAppear {
controller.viewWillAppear = viewWillAppear
}
if let viewWillDisappear = viewWillDisappear {
controller.viewWillDisappear = viewWillDisappear
}
return controller
}
func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<UIViewControllerResponder>) {
}
/// An object that manages a view hierarchy for your UIKit app.
private class ViewController: UIViewController {
var viewWillAppear: () -> Void = { }
var viewWillDisappear: () -> Void = { }
/// Notifies the view controller that its view is about to be added to a view hierarchy.
/// - Parameter animated: If true, the view is being added to the window using an animation.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
viewWillAppear()
}
/// /// Notifies the view controller that its view is about to be removed from a view hierarchy.
/// - Parameter animated: If true, the view is being added to the window using an animation.
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
viewWillDisappear()
}
}
}
And in the View, this is how you interact with the events:
struct MyView: View {
var body: some View {
NavigationStack {
Text("Home")
.navigationTitle("Some Text")
.toolbar {
ToolbarItem(placement: .primaryAction) {
Button {
print("Toolbar button pressed")
}
label: {
Image(systemName: "plus")
}
}
}
}
.onWillAppear {
let appearance = UINavigationBarAppearance()
appearance.titleTextAttributes = [.foregroundColor: UIColor.white]
appearance.largeTitleTextAttributes = [.foregroundColor: UIColor.white]
UINavigationBar.appearance().standardAppearance = appearance
UINavigationBar.appearance().compactAppearance = appearance
}
.onWillDisappear {
let appearance = UINavigationBarAppearance()
appearance.titleTextAttributes = [:]
appearance.largeTitleTextAttributes = [:]
UINavigationBar.appearance().standardAppearance = appearance
UINavigationBar.appearance().compactAppearance = appearance
}
}
}
