Questions tagged [swiftui-foreach]
120 questions
23
votes
2 answers
SwiftUI Error: "Closure containing control flow statement cannot be used with function builder 'ViewBuilder'"
I tried a SwiftUI tutorial, "Handling User Input".
https://developer.apple.com/tutorials/swiftui/handling-user-input
I tried implementing it with for instead of ForEach.
But an error arose: "Closure containing control flow statement cannot be used…
msoniku
- 231
- 1
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- 4
10
votes
0 answers
Why does ForEach initialize its Child View twice as much in SwiftUI?
I came across a weird behaviour of SwiftUI's ForEach view.
I've noticed that ForEach always initialize its child view twice as much as it should according to its repetition. Normally, when you render the view, its init is called once. But if you put…
Hollycene
- 287
- 1
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- 12
9
votes
1 answer
searchable modifier not displaying search bar below navigation bar title
I'm using iOS 15 and trying out the new searchable modifier on Lists in SwiftUI. It looks like when you attach searchable(text: $searchText) to a NavigationView the search bar renders on the screen by default below the navigation bar title. When…
Petesta
- 1,623
- 3
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- 29
7
votes
2 answers
How to update SwiftUI's ForEach in a TabView with PageTabViewStyle modifier when inserting a new element to the collection at first index
This is a very specific issue when using ForEach in a TabView with PageTabViewStyle modifier.
Every time I'm inserting an element at the beginning of my array my app crashes.
I'm getting a
attempt to delete item 11 from section 0 which only…
Marco Boerner
- 1,243
- 1
- 11
- 34
7
votes
1 answer
How to apply strikethrough() to a tapped foreach Text item in SwiftUI?
I'm trying to apply a strikethrough to any tapped Text items in a ForEach loop:
struct BrandListView: View {
@ObservedObject var list: ListObject
var body: some View {
ScrollView {
VStack…
Super Noob
- 750
- 8
- 17
6
votes
0 answers
SwiftUI CPU High Usage on Real-Time ForEach View Updating (macOS)
So I have a view and I am computing the amplitude of an audio file and then passing it to a view to graph it and it changes in real-time. The problem is that the graph gets so laggy after few seconds and CPU usage gets maximized and literally…
arata
- 859
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6
votes
2 answers
What does "\.self" actually do in swift/swiftUI?
I don't fully understand what exactly \.self does in the following code:
struct ContentView: View {
@State private var numbers = [Int]()
@State private var currentNumber = 1
var body: some View {
VStack {
List {
…
Super Noob
- 750
- 8
- 17
4
votes
2 answers
Same ForEach loop twice in one SwiftUI View
When I use a ForEach loop over an array twice within a view, I get the following warning at runtime:
LazyVGridLayout: the ID 84308994-9D16-48D2-975E-DC40C5F9EFFF is used by multiple child views, this will give undefined results!
The reason for this…
D. Mika
- 2,577
- 1
- 13
- 29
3
votes
1 answer
SwiftUI: Move rows in nested ForEach
I am trying to implement the ability to move rows in a hierarchical SwiftUI List via drag+drop. My List is build with recursive ForEach loops:
import SwiftUI
struct FileItem: Hashable, Identifiable, CustomStringConvertible {
var id: Self { self…
DaPhil
- 1,509
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3
votes
0 answers
SwiftUI: Error message when using .onMove on List built with forEach
I have an array containing some data that I want to present in a View. It should be possible to rearrange the data by holding and dragging it to its new position. I have used the .onMove modifier on a List generated using ForEach to iterate over…
cODinG iS eAsY
- 41
- 5
3
votes
3 answers
SwiftUI throwing 'Fatal error: Index out of range' when adding element for app with no explicit indexing
Why, in the following app when clicking through to 'Nice Restaurant' and trying to add a contributor, does the app crash with the error:
Swift/ContiguousArrayBuffer.swift:575: Fatal error: Index out of range?
The error, in the Xcode debugger, has no…
Jared Khan
- 333
- 2
- 12
3
votes
1 answer
Binding in SwiftUI ForEach from Parent to Child
I have a Subtask defined like this:
struct Subtask: Identifiable{
var id = UUID().uuidString
var text = ""
}
I populate an array of them in an ObservableObject like this:
//View Model
class SubtaskModel: ObservableObject {
static let shared =…
Clifton Labrum
- 13,053
- 9
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- 128
3
votes
0 answers
SwiftUI list: NSInternalInconsistencyException / invalid number of rows
I have a view CountriesListScreen, to which I am passing a list of items.
struct CountriesListScreen: View {
var listItems: CountriesListItems
var body: some View {
VStack {
Section(header: CountriesListHeader()) {
ForEach…
Daniele B
- 19,801
- 29
- 115
- 173
2
votes
1 answer
Using a ForEach loop to show the key and value of dictionary items in a Form view in SwiftUI
I'm trying to create what I thought would be a simple bit of code to show the key of a dictionary item and implement a Stepper or a Picker to modify the key's value in a single line within a Form view.
At the end of the day, all I'm trying to…
tjmcbutters
- 21
- 5
2
votes
1 answer
Is it possible to reload only modified item in SwiftUI List/ForEach that uses @Binding
Simple sample code with toggle button (slightly modified from hackingwithswift:
This code(hackingwithswift original and my version) IS redrawing every list cell whenever any toggle happens. I modified code to better debug view drawing.
import…
Oridadedles
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