I am passing binding variable into other view:
struct PocketlistView: View {
#ObservedObject var pocket = Pocket()
#State var isSheetIsVisible = false
var body: some View {
NavigationView{
List{
ForEach(Array(pocket.pockets.enumerated()), id: \.element.id) { (index, pocketItem) in
VStack(alignment: .leading){
Text(pocketItem.name).font(.headline)
Text(pocketItem.type).font(.footnote)
}
.onTapGesture {
self.isSheetIsVisible.toggle()
}
.sheet(isPresented: self.$isSheetIsVisible){
PocketDetailsView(pocketItem: self.$pocket.pockets[index])
}
}
}
.listStyle(GroupedListStyle())
.navigationBarTitle("Pockets")
}
}
}
the other view is:
struct PocketDetailsView: View {
#Binding var pocketItem: PocketItem
var body: some View {
Text("\(pocketItem.name)")
}
}
Why I see the first item when i open sheet for second or third row?
When I use NavigationLink instead of the .sheet it works perfect
You activate all sheets at once, try the following approach (I cannot test your code, but the idea should be clear)
struct PocketlistView: View {
#ObservedObject var pocket = Pocket()
#State var selectedItem: PocketItem? = nil
var body: some View {
NavigationView{
List{
ForEach(Array(pocket.pockets.enumerated()), id: \.element.id) { (index, pocketItem) in
VStack(alignment: .leading){
Text(pocketItem.name).font(.headline)
Text(pocketItem.type).font(.footnote)
}
.onTapGesture {
self.selectedItem = pocketItem
}
}
}
.listStyle(GroupedListStyle())
.navigationBarTitle("Pockets")
.sheet(item: self.$selectedPocket) { item in
PocketDetailsView(pocketItem:
self.$pocket.pockets[self.pocket.pockets.firstIndex(of: item)!])
}
}
}
}
Related
Why fullScreenCover always take just first index of an array?
This is some example of code:
struct TestView: View {
#State private var isFullScreen: Bool = false
var body: some View {
VStack{
ForEach(0..<5, id:\.self) { number in
VStack{
Text("\(number)")
.background(.red)
.foregroundColor(.white)
.padding(20)
.onTapGesture {
isFullScreen.toggle()
}
}
.fullScreenCover(isPresented: $isFullScreen) {
test2View(title: number)
}
}
}
}
}
This is the code of test2View:
struct test2View: View {
var title:Int
var body: some View {
Text("\(title)")
}
}
Whenever I click on any number it always show just 0, but when I make navigationLink instead of fullScreenCover, it works as expected, but navigationLink isn't a solution for my problem, I want that to be fullScreenCover.
It's because fullScreenCover is using a single isFullScreen for each number so only the first one works. Fix by adding a third intermediary View to hold an isFullScreen bool for each number, e.g.
struct TestView: View {
var body: some View {
VStack{
ForEach(0..<5) { number in
TestView2(number: number)
}
}
}
}
struct TestView2: View {
let number: Int
#State private var isFullScreen: Bool = false
var body: some View {
Text("\(number, format: .number)")
.background(.red)
.foregroundColor(.white)
.padding(20)
.onTapGesture {
isFullScreen.toggle()
}
.fullScreenCover(isPresented: $isFullScreen) {
TestView3(number: number)
}
}
}
struct TestView3: View {
let number: Int
var body: some View {
Text("\(number, format: .number)")
}
}
I found a solution using .fullScreenCover item parameter like this:
struct TestView: View {
#State private var isFullScreen: Int? = nil
var body: some View {
VStack{
ForEach(0..<5, id:\.self) { number in
VStack{
Text("\(number)")
.background(.red)
.foregroundColor(.white)
.padding(20)
.onTapGesture {
isFullScreen = number
}
}
.fullScreenCover(item: $isFullScreen) { item in
test2View(title: item)
}
}
}
}
}
I have this use case where I have a parent view and a child view. Both of the views have their own corresponding ViewModels.
ParentView:
struct ParentView: View {
#StateObject var parentViewModel = ParentViewModel()
var body: some View {
NavigationView {
List {
TextField("Add Name", text: $parentViewModel.newListName)
NavigationLink(destination: ChildView()) {
Label("Select Products", systemImage: K.ListIcons.productsNr)
}
}
}
}
ParentViewModel:
class ParentViewModel: ObservableObject {
#Published var newListName: String = ""
func saveList() {
// some logic to save to CoreData, method would be called via a button
// how do I reference "someString" from ChildViewModel in this ViewModel?
}
}
ChildView:
struct ChildView: View {
#StateObject var childViewModel = ChildViewModel()
var body: some View {
NavigationView {
List{
Text("Some element")
.onTapGesture {
childViewModel.alterData()
}
}
}
}
}
ChildViewModel:
class ChildViewModel: ObservableObject {
#Published var someString: String = ""
func alterData() {
someString = "Toast"
}
}
My question now is, how do I pass the new value of "someString" from ChildViewModel into the ParentViewModel, in order to do some further stuff with it?
I've tried to create a #StateObject var childViewModel = ChildViewModel() reference in the ParentViewModel, but that does obviously not work, as this will create a new instance of the ChildViewModel and therefore not know of the changes made to "someString"
Solution:
As proposed by Josh, I went with the approach to use a single ViewModel instead of two. To achieve this, the ParentView needs a .environmentObject(T) modifier.
ParentView:
struct ParentView: View {
#StateObject var parentViewModel = ParentViewModel()
var body: some View {
NavigationView {
List {
TextField("Add Name", text: $parentViewModel.newListName)
NavigationLink(destination: ChildView()) {
Label("Select Products", systemImage: K.ListIcons.productsNr)
}
}
}.environmentObject(parentViewModel)
}
The ChildView then references that environment Object via #EnvironmentObject without an initializer:
struct ChildView: View {
#EnvironmentObject var parentViewModel: ParentViewModel
var body: some View {
NavigationView {
List{
Text("Some element")
.onTapGesture {
parentViewModel.alterData()
}
}
}
}
}
Most likely you would use a binding for this situation:
struct ChildView: View {
#Binding var name: String
var body: some View {
NavigationView {
List{
Text("Some element")
.onTapGesture {
name = "Altered!"
}
}
}
}
}
And in the parent:
struct ParentView: View {
#StateObject var parentViewModel = ParentViewModel()
var body: some View {
NavigationView {
List {
TextField("Add Name", text: $parentViewModel.newListName)
NavigationLink(destination: ChildView(name: $parentViewModel.newListName)) {
Label("Select Products", systemImage: K.ListIcons.productsNr)
}
}
}
}
Also, I think you can remove the NavigationView view from ChildView. Having it ParentView is enough.
I have 2 Views in my Swift Project and when I click on the Button on the secondView, I want to update the List in the First View. I don't know how to do it! If I use a static variable in my MainView and then edit this variable from the secondView, it works, but it won't update. And if I don't use static and instead use #State, it would update, but I can't access it from my secondView.
Here is the Code below:
import SwiftUI
struct ContentView: View {
var body: some View {
TabView {
MainView()
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("MainView")
}
}.tag(0)
UpdateOtherViewFromHere()
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("SecondView")
}
}.tag(1)
}
}
}
struct MainView: View {
var arrayList: [CreateListItems] = []
init() {
let a = CreateListItems(name: "First Name!")
let b = CreateListItems(name: "Second Name!")
let c = CreateListItems(name: "Third Name!")
arrayList.append(a)
arrayList.append(b)
arrayList.append(c)
}
var body: some View {
return VStack {
ZStack {
NavigationView {
List {
ForEach(arrayList) { x in
Text("\(x.name)")
}
}.navigationBarTitle("Main View")
}
}
}
}
}
struct UpdateOtherViewFromHere: View {
func updateList() {
//Code that should remove "FirstName" from the List in MainView
}
var body: some View {
return VStack {
Button(action: {
updateList()
}) {
Image(systemName: "heart.slash")
.font(.largeTitle)
Text("Click Me!")
}
}
}
}
struct CreateListItems: Identifiable {
var id: UUID = UUID()
var name: String
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
You can share it using #State and #Binding if you put
struct ContentView: View {
#State var arrayList: [CreateListItems] = []
struct MainView: View {
#Binding var arrayList: [CreateListItems]
struct UpdateOtherViewFromHere: View {
#Binding var arrayList: [CreateListItems]
or you use the MVVM pattern and store the list in an ObservableObject and use #StateObject/#ObservedObject (source) and use #EnvironmentObject(connection) to share it between your Views.
https://developer.apple.com/documentation/swiftui/managing-model-data-in-your-app
class ParentViewModel: ObservableObject{
#Published var arrayList: [CreateListItems] = []
init(){
addSamples()
}
func addSamples() {
let a = CreateListItems(name: "First Name!")
let b = CreateListItems(name: "Second Name!")
let c = CreateListItems(name: "Third Name!")
arrayList.append(a)
arrayList.append(b)
arrayList.append(c)
}
func updateList() {
let a = CreateListItems(name: "\(arrayList.count + 1) Name!")
arrayList.append(a)
}
}
struct ParentView: View {
#StateObject var vm: ParentViewModel = ParentViewModel()
var body: some View {
TabView {
MainView().environmentObject(vm)
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("MainView")
}
}.tag(0)
UpdateOtherViewFromHere().environmentObject(vm)
.tabItem() {
VStack {
Image(systemName: "circle.fill")
Text("SecondView")
}
}.tag(1)
}
}
}
struct MainView: View {
#EnvironmentObject var vm: ParentViewModel
var body: some View {
return VStack {
ZStack {
NavigationView {
List {
ForEach(vm.arrayList) { x in
Text(x.name)
}
}.navigationBarTitle("Main View")
}
}
}
}
}
struct UpdateOtherViewFromHere: View {
#EnvironmentObject var vm: ParentViewModel
var body: some View {
return VStack {
Button(action: {
vm.updateList()
}) {
Image(systemName: "heart.slash")
.font(.largeTitle)
Text("Click Me!")
}
}
}
}
The following code creates new controls every time a button is pressed at runtime, the problem is that the picker selection is set to the same state.
How can I create new controls with different state variables so they can operate separately ?
struct ContentView: View {
#State private var numberOfControlls = 0
#State var selection: String="1"
var body: some View {
VStack {
Button(action: {
self.numberOfControlls += 1
}) {
Text("Tap to add")
}
ForEach(0 ..< numberOfControlls, id: \.self) { _ in
Picker(selection: self.$selection, label:
Text("Picker") {
Text("1").tag(1)
Text("2").tag(2)
}
}
}
}
}
How can I create new controls with different state variables so they can operate separately ?
Separate control into standalone view with own state (or view model if/when needed).
Here is a demo:
struct ContentView: View {
#State private var numberOfControlls = 0
var body: some View {
VStack {
Button(action: {
self.numberOfControlls += 1
}) {
Text("Tap to add")
}
ForEach(0 ..< numberOfControlls, id: \.self) { _ in
ControlView()
}
}
}
}
struct ControlView: View {
#State var selection: String="1"
var body: some View {
Picker(selection: self.$selection, label:
Text("Picker")) {
Text("1").tag(1)
Text("2").tag(2)
}
}
}
I tried to add a navigation view in the list as following. But it not works saying Result of 'NavigationView<Content>' initializer is unused
var body: some View {
GeometryReader { geometry in
VStack {
List {
ForEach(self.allItems){ item in
TaskRow(item: item)
.onTapGesture {
// TODO: switch to another view
NavigationView {
VStack {
Text("Hello World")
NavigationLink(destination: AnotherView()) {
Text("Do Something")
}
}
}
}
}
}
}
}
}
And AnotherView is a SwiftUI file as following:
import SwiftUI
struct AnotherView: View {
var body: some View {
VStack{
Text("Hello, World!")
}
}
}
struct AnotherView_Previews: PreviewProvider {
static var previews: some View {
AnotherView()
}
}
I have tried the solution in stackoverflow Switching Views With Observable Objects in SwiftUI and SwiftUI Change View with Button. They neither work in my situation.
How to switch to another view by onTapGesture of the list in SwiftUI like following:
var body: some View {
GeometryReader { geometry in
VStack {
List {
ForEach(self.allItems){ item in
TaskRow(item: item)
.onTapGesture {
// TODO: switch to another view
AnotherView()
}
}
}
}
}
}
You have to place whole your body into NavigationView.
Example
struct Item: Identifiable {
let id = UUID()
let name: String
}
struct ContentView: View {
var body: some View {
NavigationView {
List {
ForEach([Item(name: "A"), Item(name: "B")]) { value in
NavigationLink(destination: X(item: value)) {
Text(value.name)
}
}
}
}
}
}
struct X: View {
let item: Item
var body: some View {
Text(item.name)
}
}