Multiple back buttons created when navigates to root screen in SwiftUI - ios

say I create 3 screens in SwiftUI which contains a NavigationLink to the next screen. like, first screen navigates to 2nd screen. 2nd screen navigates to third. and the third screen navigates to the first screen. In this case even if I use NavigationView only once(in the first screen). I encountered that there's a back button forming when I navigate to 1st screen from the third screen. And it keeps adding up when I start to navigate from then on. I have tried to use .navigationBarBackButtonHidden(true). It hides it but the space taken by back button was still there.
My code is similar to this:
struct FirstScreen: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: SecondScreen()) {
Text("Go to Second Screen")
}
}
}
}
}
struct SecondScreen: View {
var body: some View {
VStack {
NavigationLink(destination: ThirdScreen()) {
Text("Go to Third Screen")
}
}
}
}
struct ThirdScreen: View {
var body: some View {
VStack {
NavigationLink(destination: FirstScreen()) {
Text("Go to First Screen")
}
}
}
}
this is the image

You're pushing the FirstScreen onto your navigation stack, but FirstScreen contains its own NavigationView. If you really want to keep pushing them on the stack, then move the NavigationView outside of FirstScreen.
struct ContentView: View {
var body: some View {
NavigationStack { // Use NavigationStack for iOS 16
FirstScreen()
}
}
}
struct FirstScreen: View {
var body: some View {
VStack {
NavigationLink(destination: SecondScreen()) {
Text("Go to Second Screen")
}
}
}
}
If you actually want to pop all the views off the stack and go back to FirstScreen you should use
init(path: Binding<NavigationPath>, etc)
Here's a simple example passing the path down the stack and resetting it to pop back to the root…
enum Screen {
case two, three
}
struct ContentView: View {
#State var path = NavigationPath()
var body: some View {
NavigationStack(path: $path) {
VStack {
// value gets appended to path
NavigationLink("Go to Second Screen", value: Screen.two)
}
// Decides which screen to show for values in path
.navigationDestination(for: Screen.self) { index in
switch index {
case .two:
SecondScreen(path: $path)
case .three:
ThirdScreen(path: $path)
}
}
}
}
}
struct SecondScreen: View {
#Binding var path: NavigationPath
var body: some View {
VStack {
NavigationLink("Go to Third Screen", value: Screen.three)
}
}
}
struct ThirdScreen: View {
#Binding var path: NavigationPath
var body: some View {
VStack {
Button("Go to First Screen") {
// reset the path to pop to root
path = NavigationPath()
}
}
}
}

Related

Get the view which was dismissed and from which the current view is display

I have a NavigationView which is showing a different view via fullScreenCover when I press a Button. Now I need to know when my view from where I pressed the Button is getting visible again and what was the view before. In the view shown by the fullScreenCover im using #Environment(\.dismiss) var dismiss to dismiss it.
So here is my concrete use case:
I have my main screen with two Buttons A and B.
A is showing sub view 1 and B is showing sub view 2.
When I dismiss one of these sub screens I need to know if I was in A view 1 or 2 before.
Is this somehow possible?
You can use the .onDisappear on the view that is linked on the destination of the NavigationLink. See this example:
import SwiftUI
struct ContentView: View {
#State var selectedSubView: ViewSelection = ViewSelection.zero
var body: some View {
NavigationView {
VStack {
// Version 1
NavigationLink (
destination: SubView1()
.onDisappear {
self.selectedSubView = .one
print(self.selectedSubView) // debug
},
label: {
Text("To ViewOne").padding()
})
// Version 2
NavigationLink (
destination: SubView2()
.onDisappear {
self.selectedSubView = .two
print(self.selectedSubView) // debug
},
label: {
Text("To ViewTwo")
.padding()
})
}
}
}
}
struct SubView1: View {
var body: some View {
Text("View 1")
}
}
struct SubView2: View {
var body: some View {
Text("View 2")
}
}
enum ViewSelection {
case one
case two
case zero
}
You can use .fullScreenCover with an onDismiss closure.
(Here I used .sheet because it's easier to test, but it's the same)
struct SwiftUIView4: View {
#State private var destination: Destination?
#State private var showed: Destination?
#State private var dismissed: Destination?
var body: some View {
VStack {
HStack {
Button("A") {
destination = .firstView
showed = .firstView
}.padding()
Spacer()
Button("B") {
destination = .secondView
showed = .secondView
}.padding()
}
Text("Just dismissed : \(dismissed?.rawValue ?? "nothing")")
.sheet(item: $destination, onDismiss: {
dismissed = showed
}, content: { destination in
switch destination {
case .firstView: Text("A clicked")
case .secondView: Text("B clicked")
}
})
}
}
}
enum Destination: String, Identifiable {
case firstView, secondView
var id: Destination { self }
}
Or you could use a custom Binding for the item parameter of your .fullScreenCover :
struct SwiftUIView4: View {
#State private var showed: Destination?
#State private var dismissed: Destination?
var body: some View {
VStack {
HStack {
Button("A") {
showed = .firstView
}.padding()
Spacer()
Button("B") {
showed = .secondView
}.padding()
}
Text("Just dismissed : \(dismissed?.rawValue ?? "nothing")")
.sheet(item: .init(get: {showed}, set: {
dismissed = showed // HERE
showed = $0 // <<<<
})) { destination in
switch destination {
case .firstView: Text("A clicked")
case .secondView: Text("B clicked")
}
}
}
}
}

Can I navigate ParentView to another View by button in ChildView?, swiftUI

I'm new to SwiftUI and struggling to move MainView to LoginView by clicking Text() in ChildView.
I tried make NavigationView and NavigationLink like this code but it's not working. It's much more complex in real code but I show only simple structure of my code to explain.
struct ContentView: View {
#State private var currViewIdx: Int = 0
var body: some View {
NavigationView {
CurrentView(currViewIdx: $currViewIdx)
}
}
}
struct CurrentView: View {
#Binding var currViewIdx: Int
var body: some View {
if self.currViewIdx == 0 {
HomeView()
.onTapGesture {
self.currViewIdx = 0
}
} else {
//SomeView.onTapGesture(self.currViewIdx = 1)
}
}
}
struct HomeView: View {
var body: some View {
NavigationLink(destination: TestView()) {
Text("Go TestView")
.contentShape(Rectangle())
}
}
}
struct TestView: View {
var body: some View {
Text("Here is Test View")
}
}
I think, the top hierarchy view, ContentView, has NavigationView and it should be changed when I click Text("Go TestView") in HomeView because it's in NavagationLink.
But the ContentView is not changed to TestView although I touch Text("Go TestView"). How to solve this problem? I considered way to add one more State value to change top level view, but it seems not good if I'll make lots of more values
Thank you

Navigate to same view in SwiftUI

So I'm trying to navigate from one view to another in SwiftUI and have stumbled upon a problem.
My views looks like this and trying to navigation from one DetailView to another DetailView but as soon I push the navigation link I'm forced back to the first DetailView.
Any ideas on how to achieve navigation to the same view in SwiftUI?
ListView.swift
struct ListView: View {
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: DetailView(data: data)) {
Text("Navigate")
}
}
}
}
}
DetailView.swift
struct DetailView: View {
var body: some View {
VStack {
NavigationLink(destination: DetailView(data: otherData)) {
Text("Navigate")
}
}
}
}
EDIT:
Remove the NavigationView in DetailView as pointed out below but still facing the same issue.
Remove NavigationView from DetailView, there should be only one in stack, so when you navigate all new links are opened in original NavigationView:
struct DetailView: View {
var body: some View {
VStack {
NavigationLink(destination: DetailView(data: otherData)) {
Text("Navigate")
}
}
}
}

Navigation of Pop and Push not working in SwiftUI?

I have two screens. First screen has following code
NavigationLink(destination: SecondScreen()) {
Text("Scan Qr Code")
}
The NavigationLink navigates to second screen which works as expected. In the second screen
struct SecondScreen: View {
#Environment(\.presentationMode) var presentation
var body: some View{
Button("Done") {
self.presentation.wrappedValue.dismiss()
}
}}
The button in second screen pops to first screen which works as expected, but as soon as I come back to first screen and I click NavigationLink, it does not move to second screen.
Here is a solution. Use a button on the first screen instead of the navigation link and use that button to pop out a sheet. I tested this and it worked for me!
struct ContentView: View {
#State private var showingAddExpense = false
var body: some View {
NavigationView{
Button(action: {
self.showingAddExpense = true
}) {
Text("Button")
}
.sheet(isPresented: $showingAddExpense) {
SecondScreen()
}
}
}
}
struct SecondScreen: View {
#Environment(\.presentationMode) var presentation
var body: some View{
NavigationView{
Button("Done") {
self.presentation.wrappedValue.dismiss()
}
}
}
}

How to display missing back button in Master-Detail1-Detail2 view in SwiftUI in landscape?

I'm using a NavigationView and NavigationLinks to move from a MasterView to a Detail1View and then further to a Detail2View.
On an iPhone in portrait mode, the back button is displayed for all detail views and allows to move back from Detail2View to Detail1View, and then further to MasterView.
But on an iPhone in landscape mode or on an iPad, when moving from Detail1View to Detail2View, there is no back button. And it is thus impossible to go back to Detail1View.
Adding a 2nd NavigationView allows to have a back button, but it's not really a desirable workaround, as the 2nd UINavigationViewController is shown below the 1st one.
struct MyMasterView: View {
private let names = ["Homer", "Marge", "Bart", "Lisa"]
var body: some View {
List() {
Section(header: Text("The Simpsons")) {
ForEach(names, id: \.self) { name in
NavigationLink(destination: MyDetail1View(name: name)) {
Text(name)
}
}
}
}
.navigationBarTitle(Text("My App"))
}
}
struct MyDetail1View: View {
var name: String
var body: some View {
//NavigationView {
List {
NavigationLink(destination: MyDetail2View(name: name)) {
Text("Hello \(name)")
}
}
.navigationBarTitle(Text("Details 1"))
//}
}
}
struct MyDetail2View: View {
var name: String
var body: some View {
HStack {
Text("\(name), I'm sorry but in Landscape there is no back button...")
}
.navigationBarTitle(Text("Details 2"))
}
}
struct ContentView : View {
var body: some View {
NavigationView {
MyMasterView()
Text("In Landscape, swipe to start...")
}
}
}
The answer turns out to be as simple as using isDetailLink()!
NavigationLink(destination: MyDetail2View(name: name)) {
Text("Hello \(name)")
}.isDetailLink(false)
Credits to https://stackoverflow.com/a/57400873/2893408

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