NavigationStack causes microhang when loading sheet

Question

I have a simple sheet:

.sheet(isPresented: $newContactSheetTrigger) {
 NewContactSheet()
 .presentationDetents([.large])
}

with the following code:

import SwiftUI
import SwiftData
import WidgetKit
struct NewContactSheet: View {
 
 @Environment(\.dismiss) private var dismiss
 @State private var contactName = ""
 @State private var newDaysDue: Set<String> = []
 @State private var favorite = false
 private let templatesHeight = UIScreen.main.bounds.height * 0.035
 private let dayWidth = UIScreen.main.bounds.width * 0.1
 private let weekdays: [String] = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
 private let buttonBackground = Color(uiColor: .systemGroupedBackground)
 private let green85 = Color.green.opacity(0.85)
 private let green30 = Color.green.opacity(0.3)
 private let adaptiveBlack = Color("AdaptiveBlack")
 
 var body: some View {
 NavigationStack {
 Form {
 Section {
 TextField("Contact name", text: $contactName)
 HStack {
 Text("Templates:")
 .font(.footnote)
 .foregroundStyle(.secondary)
 
 ScrollView(.horizontal, showsIndicators: false) {
 LazyHStack {
 ForEach(NewContactTemplate.predefinedTemplates) { template in
 Button {
 if contactName == template.name {
 clearTemplate()
 } else {
 applyTemplate(template: template)
 }
 } label: {
 Text("\(template.name)")
 .padding(.horizontal)
 .font(.footnote)
 .frame(height: templatesHeight)
 .foregroundStyle(adaptiveBlack)
 }
 .background(buttonBackground, in: RoundedRectangle(cornerRadius: 10))
 .buttonStyle(.borderless)
 }
 }
 }
 .contentMargins(.horizontal, 0)
 }
 } header: {
 Text("Name")
 }
 Section {
 HStack (alignment: .center) {
 Spacer()
 ForEach (weekdays, id: \.self) { day in
 let containsCheck = newDaysDue.contains(day)
 Button {
 if favorite {
 // activeAlert = .correctDaysSelector
 // showAlert = true
 } else {
 if containsCheck {
 newDaysDue.remove(day)
 } else {
 newDaysDue.insert(day)
 }
 }
 } label: {
 Text(day)
 .font(.caption)
 .frame(width: dayWidth, height: templatesHeight)
 .background(
 containsCheck ?
 RoundedRectangle(cornerRadius: 10)
 .fill(green85)
 .overlay(
 RoundedRectangle(cornerRadius: 10)
 .stroke(.clear, lineWidth: 2)
 )
 
 :
 RoundedRectangle(cornerRadius: 10)
 .fill(.clear)
 .overlay(
 RoundedRectangle(cornerRadius: 10)
 .stroke(green30, lineWidth: 2)
 )
 )
 .foregroundStyle(favorite ? .gray : containsCheck ? .white : green85)
 }
 .buttonStyle(.plain)
 }
 Spacer()
 }
 
 HStack {
 Text("Presets:")
 .font(.footnote)
 .foregroundStyle(.secondary)
 
 ScrollView(.horizontal, showsIndicators: false) {
 LazyHStack {
 ForEach(NewContactDaysDue.predefinedTemplates) { template in
 Button {
 if newDaysDue.count == template.daycount {
 newDaysDue = []
 } else {
 newDaysDue = template.daysDue
 }
 } label: {
 Text("\(template.name)")
 .padding(.horizontal)
 .font(.footnote)
 .frame(height: templatesHeight)
 .foregroundStyle(adaptiveBlack)
 }
 .buttonStyle(.borderless)
 .background(buttonBackground, in: RoundedRectangle(cornerRadius: 10))
 }
 }
 }
 .contentMargins(.horizontal, 0)
 }
 } header: {
 Text("Meet")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 Section {
 
 } header: {
 Text("xxx")
 }
 }
 .scrollIndicators(.hidden)
 .toolbar {
 ToolbarItem(placement: .topBarLeading) {
 Button {
 dismiss()
 } label: {
 Text("Cancel")
 .foregroundStyle(.red)
 }
 }
 ToolbarItem(placement: .topBarTrailing) {
 Button {
 //implement save logic
 WidgetCenter.shared.reloadAllTimelines()
 dismiss()
 } label: {
 Text("Save")
 .foregroundStyle(.green)
 }
 }
 }
 .navigationTitle("New Contact")
 .navigationBarTitleDisplayMode(.inline)
 .navigationBarHidden(false)
 }
 
 }
 
 func applyTemplate(template: NewContactTemplate) {
 contactName = template.name
 }
 
 func clearTemplate() {
 contactName = ""
 }
}
#Preview {
 NewContactSheet()
}
struct NewContactTemplate: Identifiable {
 let id = UUID()
 let name: String
 let daysDue: Set<String>
}
extension NewContactTemplate {
 static let predefinedTemplates: [NewContactTemplate] = [
 NewContactTemplate(name: "Test1",
 daysDue: ["Mon", "Tue", "Wed"]),
 NewContactTemplate(name: "Test2",
 daysDue: ["Tue", "Wed", "Fri"]),
 NewContactTemplate(name: "Test3",
 daysDue: ["Sat", "Sun", "Mon"])
 ]
}
struct NewContactDaysDue: Identifiable {
 let id = UUID()
 let name: String
 let daysDue: Set<String>
 let daycount: Int
}
extension NewContactDaysDue {
 static let predefinedTemplates: [NewContactDaysDue] = [
 NewContactDaysDue(name: "Daily", daysDue: ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"], daycount: 7),
 NewContactDaysDue(name: "Weekdays", daysDue: ["Mon", "Tue", "Wed", "Thu", "Fri"], daycount: 5),
 NewContactDaysDue(name: "Weekend", daysDue: ["Sat", "Sun"], daycount: 2)
 ]
}

However when I tap on the button that triggers it I get a microhang in my profiler (testing on an actual device not simulator). enter image description here

No matter how much I try to optimise the code I can't get rid of it, any suggestions on how to avoid these microhangs?

I'm targeting iOS 17.0+

Any help would be very much appreciated

• workingdog support Ukraine: Well how about showing a minimal reproducible code that produces your issue, see: minimal code, not just some bits of a NavigationStack code.
• Alan: Sure! I edited the question and added enough code to fully reproduce the issue