I have a modal sheet that is presented from my home view as such:
Button(action: {
...
}) {
...
}
.sheet(isPresented: ...) {
MySheetView()
}
In MySheetView, there is a NavigationView and a NavigationLink to push another view onto its view stack (while I'm on MySheetView screen and use the view inspector, there's only one UINavigationController associated with it which is what I expect).
However, as soon as I get to my next view that is presented from MySheetView using the NavigationLink, and I use the view hierarchy debugger, there are TWO UINavigationControllers on-top of each other. Note, this view does NOT have a NavigationView inside it, only MySheetView does.
Does anyone know what's going on here? I have a feeling this is causing some navigation bugs im experiencing. This can be easily reproduced in an example app with the same structure.
Ex:
// These are 3 separate SwiftUI files
struct ContentView: View {
#State var isPresented = false
var body: some View {
NavigationView {
Button(action: { self.isPresented = true }) {
Text("Press me")
}
.sheet(isPresented: $isPresented) {
ModalView()
}
}
}
}
struct ModalView: View {
var body: some View {
NavigationView {
NavigationLink(destination: FinalView()) {
Text("Go to final")
}
}
}
}
struct FinalView: View {
var body: some View {
Text("Hello, World!")
}
}
I don't observe the behaviour you described. Used Xcode 11.2. Probably you need to provide your code to find the reason.
Here is an example of using navigation views in main screen and sheet. (Note: removing navigation view in main screen does not affect one in sheet).
import SwiftUI
struct TestNavigationInSheet: View {
#State private var hasSheet = false
var body: some View {
NavigationView {
Button(action: {self.hasSheet = true }) {
Text("Show it")
}
.navigationBarTitle("Main")
.sheet(isPresented: $hasSheet) { self.sheetContent }
}
}
private var sheetContent: some View {
NavigationView {
VStack {
Text("Properties")
.navigationBarTitle("Sheet")
NavigationLink(destination: properties) {
Text("Go to Inspector")
}
}
}
}
private var properties: some View {
VStack {
Text("Inspector")
}
}
}
struct TestNavigationInSheet_Previews: PreviewProvider {
static var previews: some View {
TestNavigationInSheet()
}
}
Related
I started to use SwiftUI after a couple years of UIKit.. This is not a piece of cake lol.
Alright, so I am trying to build an app that has a tab bar with 2 elements. Each Tab with contain a ViewController (View now) and they will be embedded in a NavigationController (NavigationView now)
The actual result is this
and I am expecting to have a nav bar with a title set to Home.
Could you explain me what I do wrong here? i followed the documentation and a couple tutorials, and I don't seem to do differently.
import SwiftUI
struct TabBarView: View {
var body: some View {
TabView() {
RedView()
.tabItem({
Image(systemName: "house.fill")
Text("Home")
})
.tag(0)
BlueView()
.tabItem({
Image(systemName: "dollarsign.square.fill")
Text("Trade")
})
.tag(1)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
TabBarView()
}
}
struct RedView: View {
var body: some View {
NavigationView {
List {
Text("test")
}
}
.navigationBarTitle("Home")
}
}
struct BlueView: View {
var body: some View {
NavigationView {
List {
Text("test2")
}
}
.navigationBarTitle("Trade")
}
}
This is the file that contains everything at the moment. Thanks in advance for any future help!
The .navigationBarTitle should be inside NavigationView
struct RedView: View {
var body: some View {
NavigationView {
List {
Text("test")
}
.navigationBarTitle("Home") // << here !!
}
}
}
I have lately been trying to make a tvOS app, but have run into the following rather annoying problem. I can't use navigation inside a TabView and still have the menu button on the remove take me back to the previous state.
struct TestView: View {
#State var selection : Int = 0
var body: some View {
TabView(selection: self.$selection) {
ExpView()
.tabItem {
HStack {
Image(systemName: "magnifyingglass")
Text("Explore")
}
}
.tag(0)
}
}
}
struct ExpView: View {
var body: some View {
NavigationView {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}
My question is: Is there any way to enable the menu button to go back to the previous view in the hierachy without dismissing the app completely?
You don't need to call dismiss on Menu it is called automatically for NavigationLink (so calling one more dismiss quits to main menu)
Here are fixed views. Tested with Xcode 11.4
struct ExploreView: View {
var body: some View {
NavigationView {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}
So I found a workaround for the issue.
If you place the navigationView outside the TabView and then use the following code it works:
struct TestView: View {
#State var selection : Int = 0
#State var hideNavigationBar : Bool
var body: some View {
NavigationView {
TabView(selection: self.$selection) {
ExpView(hideNavigationBar: self.$hideNavigationBar)
.tabItem {
HStack {
Image(systemName: "magnifyingglass")
Text("Explore")
}
}
.tag(0)
}
}
}
}
struct ExpView: View {
#Binding var hideNavigationBar : Bool
var body: some View {
NavigationLink(destination: DetailView(title: "Hey")) {
Text("Detail")
}.navigationBarTitle("")
.navigationBarHidden(self.hideNavigationBar)
.onAppear {
self.hideNavigationBar = true
}
}
}
struct DetailView: View {
var title : String
var body: some View {
VStack {
Text(title)
}
}
}
I have a Content file and am hiding the navigation bar because it takes up space and pushes elements down. One of the buttons in the ContentView redirects (using a navigation link) to another view. In this other view, the navigationBar is still hidden....for simplicity sake, I'll cut out some of the code from ContentView:
//this is the view that looks "fine" (i.e. the navigation bar takes up no space)
struct ContentView: View {
#State private var isPresentedSettings = false
var body: some View {
NavigationView {
ZStack {
VStack {
SettingsButton(isPresentedSettings: $isPresentedSettings)
}
}.navigationBarTitle("").navigationBarHidden(true)
}
}
}
//this is the button that pulls up the settings page view
struct SettingsButton: View {
#Binding var isPresentedSettings: Bool
var body: some View {
NavigationLink (destination: SettingsPageView(isPresentedSettings:
self.$isPresentedSettings)) {
Button(action: { self.isPresentedSettings.toggle() }, label: { Text("Button") })
}
}
}
//This is the view that should have a navigationbar but it doesn't
struct SettingsPageView: View {
#Binding var isPresentedSettings: Bool
var body: some View {
NavigationView {
VStack {
Text("This is a view")
}.navigationBarTitle("Settings", displayMode: .inline)
}
}
}
Also...there may have been typos because I just copied the code over from another computer. Sorry and thank you in advance!
Firstly, you don't need to have this isPresentedSettings variable for presenting a NavigationLink.
NavigationLink(destination: SettingsPageView()) {
Text("Button")
}
And there should be only one NavigationView in your view hierarchy.
This is how your final code can look like:
struct ContentView: View {
#State private var navBarHidden = true
var body: some View {
NavigationView {
ZStack {
VStack {
SettingsButton(navBarHidden: $navBarHidden)
}
}
.navigationBarHidden(navBarHidden)
}
}
}
struct SettingsButton: View {
#Binding var navBarHidden: Bool
var body: some View {
NavigationLink(destination: SettingsPageView(navBarHidden: $navBarHidden)) {
Text("Show View")
}
}
}
struct SettingsPageView: View {
#Binding var navBarHidden: Bool
var body: some View {
VStack {
Text("This is a view")
}
.navigationBarTitle("Settings", displayMode: .inline)
.onAppear {
self.navBarHidden = false
}
.onDisappear {
self.navBarHidden = true
}
}
}
I'm currently trying to present a modal view by pressing a button in the context menu. This works, but the code which should present the modal view is called twice and this is a problem, because I'm calling some networking requests.
Here is my currently demo project (without networking stuff):
This is the view which is called on app start.
struct ContentView: View {
#State var isModal: Bool = false
var body: some View {
Group {
Text("Main view")
}.contextMenu {
Button("Present Detail") { self.isModal = true }.sheet(isPresented: $isModal) {
DetailView()
}
}
}
}
This is the simple detail view
struct DetailView: View {
var body: some View {
Text("Detail View")
}
}
So if I place a breakpoint at the line where the DetailView() is instantiated, I see that this part is called twice. Is there a better solution to present the modal view, without being instantiated multiple times?
Use instead
var body: some View {
Group {
Text("Main view")
}.contextMenu {
Button("Present Detail") { self.isModal = true }
}.sheet(isPresented: $isModal) {
DetailView()
}
}
As detailed here (on an iOS topic), the following code can be used to make a SwiftUI View dismiss itself:
#Environment(\.presentationMode) var presentationMode
// ...
presentationMode.wrappedValue.dismiss()
However, this approach doesn't work for a native (not Catalyst) macOS NavigationView setup (such as the below), where the selected view is displayed alongside the List.
Ideally, when any of these sub-views use the above, the list would go back to having nothing selected (like when it first launched); however, the dismiss function appears to do nothing: the view remains exactly the same.
Is this a bug, or expected macOS behaviour?
Is there another approach that can be used instead?
struct HelpView: View {
var body: some View {
NavigationView {
List {
NavigationLink(destination:
AboutAppView()
) {
Text("About this App")
}
NavigationLink(destination:
Text("Here’s a User Guide")
) {
Text("User Guide")
}
}
}
}
}
struct AboutAppView: View {
#Environment(\.presentationMode) var presentationMode
public var body: some View {
Button(action: {
self.dismissSelf()
}) {
Text("Dismiss Me!")
}
}
private func dismissSelf() {
presentationMode.wrappedValue.dismiss()
}
}
FYI: The real intent is for less direct scenarios (such as triggering from an Alert upon completion of a task); the button setup here is just for simplicity.
The solution here is simple. Do not use Navigation View where you need to dismiss the view.
Check the example given by Apple https://developer.apple.com/tutorials/swiftui/creating-a-macos-app
If you need dismissable view, there is 2 way.
Create a new modal window (This is more complicated)
Use sheet.
Following is implimenation fo sheet in macOS with SwiftUI
struct HelpView: View {
#State private var showModal = false
var body: some View {
NavigationView {
List {
NavigationLink(destination:
VStack {
Button("About"){ self.showModal.toggle() }
Text("Here’s a User Guide")
}
) {
Text("User Guide")
}
}
}
.sheet(isPresented: $showModal) {
AboutAppView(showModal: self.$showModal)
}
}
}
struct AboutAppView: View {
#Binding var showModal: Bool
public var body: some View {
Button(action: {
self.showModal.toggle()
}) {
Text("Dismiss Me!")
}
}
}
There is also a 3rd option to use ZStack to create a Modal Card in RootView and change opacity to show and hide with dynamic data.