This question already has an answer here:
how to switch tab programmatically on button click? in swiftui
(1 answer)
Closed 1 year ago.
I know this question has been asked before and I found a few of them but mine is slightly different.
I found this for example:
Programmatically change to another tab in SwiftUI
which works fine if you have the struct ContentView: View {...} and struct FirstView: View {...} on the same Swift file.
But in my project, I have the struct ContentView: View {...} in 1 Swift file and struct FirstView: View {...} in another separate swift file.
for that reason, when I use #Binding var tabSelection: Int in my FirstView() file, I get this error in my ContentView file: Argument passed to call that takes no arguments
Could someone please advice on this issue?
For example, if you try this example it would working! It would not make any deference in result at all if you put them in deferent files!
File ContentView:
import SwiftUI
struct ContentView: View {
#State private var tabSelection = 1
var body: some View {
TabView(selection: $tabSelection) {
FirstView(tabSelection: $tabSelection)
.tabItem {
Text("Tab 1")
}
.tag(1)
SecondView(tabSelection: $tabSelection)
.tabItem {
Text("Tab 2")
}
.tag(2)
}
}
}
File FirstView:
import SwiftUI
struct FirstView: View {
#Binding var tabSelection: Int
var body: some View {
Button(action: { tabSelection = 2 }) { Text("Change to tab 2") }
}
}
File SecondView:
import SwiftUI
struct SecondView: View {
#Binding var tabSelection: Int
var body: some View {
Button(action: { tabSelection = 1 }) { Text("Change to tab 1") }
}
}
Related
Good afternoon,
I have a problem on my app with the NavigationViews. When launching the app for the very first time, users are displayed a LogIn and Sign Up page (which does not have a TabView) and once they Log-In they are directed to a TabView with different sections (Home, Chats, etc...).
The main problem that I have is that when changing from the Login view to the TabView,the NavigationTitle that is set is only that of HomeView and when changing to a different tab, the title does not change. How could I solve this problem, how do other apps deal with this?
Thank you.
File LoginView
import SwiftUI
struct LoginView: View {
var body: some View{
NavigationView{
NavigationLink(destination: TabView, label: Text("Login")
}
}
}
File TabView
import Swift UI
struct TabView: View {
var body: some View{
TabView {
HomeView()
.tabItem{
//Not relevant code
}
ChatView()
.tabItem{
//Not relevant code
}
}
}
}
File HomeView
import SwiftUI
struct HomeView: View {
var body: some View {
ZStack{
//Not relevant code
}
.navigationBarTitle("Home")
}
}
File ChatsView
import SwiftUI
struct ChatsView: View {
var body: some View {
ZStack{
//Not relevant code
}
.navigationBarTitle("Chats")
}
}
struct ContentView: View {
enum Tab {
case homeView
case chatView
}
#State var selecion: Tab = .homeView
#State var title = "House"
var body: some View{
TabView(selection: $selecion){
HomeView()
.tabItem{
//Not relevant code
Image(systemName: "house")
}
.tag(Tab.homeView)
.onAppear {
title = "House"
}
ChatsView()
.tabItem{
//Not relevant code
Image(systemName: "star")
}
.tag(Tab.chatView)
.onAppear {
title = "Chat"
}
}
.navigationTitle(title)
}
}
Im trying to show another view with SwiftUI, when a button is pressed. Here is what I am trying:
import SwiftUI
struct Home: View {
var body: some View {
VStack {
Text(/*#START_MENU_TOKEN#*/"Hello, World!"/*#END_MENU_TOKEN#*/)
Button("Press here!") {
iPhone13About()
}
}
}
}
Where I hover over iPhone13About(), it says, "Result of 'iPhone13About' initializer is unused". Im a beginner with Xcode, and I am trying to mess around with Xcode and to create something.
The Swift UI View is called iPhone13.swift, and the function it is passing is
struct iPhone13About: View {
Thanks in advance!
try this.
struct iPhone13About: View {
#Environment(\.dismiss) var dismiss
var body: some View {
Button("Press to dismiss") {
dismiss()
}
.font(.title)
.padding()
.background(Color.black)
}
}
struct HomeView: View {
#State private var iPhone13Flag = false
var body: some View {
Button("iPhone13About") {
iPhone13Flag.toggle()
}
.sheet(isPresented: $showingSheet) {
SheetView()
}
}
}
I am new to Swift & iOS dev in general.
I am building an app in SwiftUI. Assume there are 2 separate views in different files: MainView() & Results() and TabBar()(ignore the naming, this is just an example)(those 2 views are ON 2 SEPARATE TABS)
My goal is to press on that button FROM ResultsView() and change the textValue property of MainView() to something else & then display the change ON the MainView(). How can I do that? P.S Please ignore alignment & etc. I am new to StackOverflow
struct MainView: View {
#State var textValue: String = "Old Text"
var body: some View {
Text(textValue)
}
}
struct TabBar: View {
var body: some View {
TabView {
MainView()
.tabItem {
Label("Main", systemImage: "circle.dashed.inset.filled")
}
ResultsView()
.tabItem {
Label("Results", systemImage: "person.2.crop.square.stack.fill")
}
}
}
}
struct ResultsView: View {
var body: some View {
Button {
// HOW TO UPDATE MainView.textValue?
} label: {
Text("Update")
}
}
}
ContentView() just has TabBar() in body
Basically, my question is how do we change UI of certain view from another view? Without NavigationLink
Might sound like a rookie question, but any reply will be so appreciated!
You can achieve this by passing the textValue from MainView to DetailView through a #Binding.
struct MainView: View {
#State private var text: String = "Original"
var body: some View {
NavigationView {
VStack {
Text(text)
NavigationLink("Detail", destination: DetailView(text: $text))
}
}
}
}
struct DetailView: View {
#Binding var text: String
var body: some View {
Button("Change Text") {
text = "New Text"
}
}
}
I recommend you read this article about bindings as it explains how to change a view from elsewhere.
Edit:
Because you mentioned, that both views are in a TabBar, here should be a working example:
struct ContentView: View {
#State private var text: String = "Original Text"
var body: some View {
TabView {
MainView(text: $text)
.tabItem { ... }
DetailView(text: $text)
.tabItem { ... }
}
}
}
struct MainView: View {
#Binding var text: String
var body: some View {
Text(text)
}
}
struct DetailView: View {
#Binding var text: String
var body: some View {
Button("Change Text") {
text = "New Text"
}
}
}
I understand its new, but this seems like pretty basic functionality that is not here. When implementing a .searchable in the new iOS 15, it would seem that a NavigationLink does not work, at all.
Ideally, the searchable would produce a filtered list with a ForEach and for each item, a Nav Link could take you to another view based on your selection. The ForEach and list works and looks beautiful, it just wont take you anywhere.
Watching WWDC21, they talk an awful lot about .searchable, but very little demonstration/example is given..
Here is a simple example, with no ForEach loop, that shows it does not work at all.. Am I missing something?
Any insight appreciated:
import SwiftUI
struct ContentView: View {
#State private var term = ""
var body: some View {
NavigationView {
Text("Hello, world!")
.padding()
}
.searchable(text: $term) {
NavigationLink(destination: SecondView()) {
Text("Go to second view")
}
}
}
}
struct SecondView: View {
var body: some View {
Text("Goodbye!")
.padding()
}
}
NavigationLink must always be inside NavigationView, no matter what. If you want to put it outside, like inside .searchable, you should use programmatic navigation with isActive.
struct ContentView: View {
#State private var term = ""
#State private var isPresenting = false
var body: some View {
NavigationView {
/// NavigationView must only contain 1 view
VStack {
Text("Hello, world!")
.padding()
/// invisible NavigationLink
NavigationLink(destination: SecondView(), isActive: $isPresenting) { EmptyView()}
}
}
.searchable(text: $term) {
Button { isPresenting = true } label: {
Text("Go to second view")
}
}
}
}
struct SecondView: View {
var body: some View {
Text("Goodbye!")
.padding()
}
}
Result:
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 !!
}
}
}