this is the code
struct ContentView: View {
@State var path = NavigationPath()
var body: some View {
NavigationStack(path: $path){
List{
NavigationLink {
View1(){
print(path.count)
print(path)
}
} label: {
Text("level0 ")
}
}
}
}
}
struct View1: View {
var go: () -> Void
var body: some View {
List{
NavigationLink {
View2(){
go()
print("went to view2")
}
} label: {
Text("level 1 ")
}
}
.onAppear(){
print("view1 enter")
go()
}
}
}
struct View2: View {
var go: ()-> Void
var body: some View {
List{
NavigationLink {
View3(){
go()
print("went to view3")
}
} label: {
Text("level 2 ")
}
}
.onAppear(){
print("view2 enter")
go()
}
}
}
struct View3: View {
var go: ()-> Void
var body: some View {
List{
Text("level 3")
.onAppear(){
print("view3 enter")
go()
}
}
}
}
and this is the print log
view1 enter
0
NavigationPath(_items: SwiftUI.NavigationPath.(unknown context at $1c5c2c248).Representation.eager([]), subsequentItems: [], iterationIndex: 0)
view2 enter
0
NavigationPath(_items: SwiftUI.NavigationPath.(unknown context at $1c5c2c248).Representation.eager([]), subsequentItems: [], iterationIndex: 0)
went to view2
view3 enter
0
NavigationPath(_items: SwiftUI.NavigationPath.(unknown context at $1c5c2c248).Representation.eager([]), subsequentItems: [], iterationIndex: 0)
went to view2
went to view3
question
NavigationPath not updating with NavigationStack,
when I open view1 and view2 ,why NavigationPath not update?
Hi @zhifang ,
You'll need to use .navigationDestination to ensure that these views are getting appended to the NavigationPath. I put together some code that I'll paste below which may help. It uses a struct called Page that has a title and a destination. The navigation destination displays a view with a NavigationLink to the next view that has a link to the next and so on. I keep track of which page we're on with a "currentPage" variable. Take a look at the documentation here for more information. You'll see the path count getting printed each time you click on a NavigationLink.
struct ContentView: View {
@State var path = NavigationPath()
@State private var dests: [Page] = [.init(title: "level1", destination: "level2"), .init(title: "level2", destination: "level3"), .init(title: "level3", destination: "level4")]
@State private var currPage: Int = 0
var body: some View {
NavigationStack(path: $path){
ListView(dests: $dests, currPage: $currPage)
.navigationDestination(for: String.self) {
_ in
ListView(dests: $dests, currPage: $currPage)
.onAppear {
print(path.count)
currPage += 1
}
}
}
}
}
struct ListView: View {
@Binding var dests: [Page]
@Binding var currPage: Int
var body: some View {
List {
NavigationLink(dests[currPage].title, value: dests[currPage].destination)
}
}
}
struct Page: Identifiable, Hashable {
var id = UUID()
var title: String
var destination: String
init(id: UUID = UUID(), title: String, destination: String) {
self.id = id
self.title = title
self.destination = destination
}
}
