I have a details screen on my app and for some reason when I try to put a picker inside the list I'm getting an empty gray box, and I can see it only if I scroll inside this gray box. Can someone help me, please?
Note: I'm a beginner in iOS development :-)
Thanks
My code:
struct GoalDetailsView: View {
var id: String
var authorId: String
var name: String
var description: String
var startDate: String
var endDate: String
var numTarget: String
var numUnit: String
var category: String
#State var numUnitIndex = 0
var units = ["other", "Kg", "$$", "Km", "Hours", "Days", "Weeks", "%"]
var body: some View {
NavigationView {
List {
Button(action: {}, label: {
Text("Name: \(name)")
})
Button(action: {}, label: {
Text("Description: \(description)")
})
Button(action: {}, label: {
Text("Numerical Target: \(numTarget)")
})
Form {
Section {
Picker(selection: $numUnitIndex, label: Text("Numerical Unit")) {
ForEach(0 ..< units.count) {
Text(self.units[$0]).tag($0).foregroundColor(.blue)
}
}
}
}
Spacer()
}.navigationBarTitleDisplayMode(.inline)
.navigationTitle("Goal Details")
}
}
}
struct GoalDetailsView_Previews: PreviewProvider {
static var previews: some View {
GoalDetailsView(id: "", authorId: "", name: "", description: "", startDate: "", endDate: "", numTarget: "", numUnit: "", category: "")
}
}
you could try this, or some variation of it:
Form {
Section {
Picker(selection: $numUnitIndex, label: Text("Numerical Unit")) {
ForEach(0 ..< units.count) {
Text(self.units[$0]).tag($0).foregroundColor(.blue)
}
}
.pickerStyle(.inline) // <-- here
}
}.scaledToFit() // <-- here
Related
I have a details screen and i want to display outside the list a Text() view and then another List, but when i adding the Text() below and outside the List i can't see the view
Part of my code:
var body: some View {
NavigationView {
List {
Button(action: {}, label: {
Text("Name: \(name)")
})
Button(action: {}, label: {
Text("Description: \(description)")
})
Button(action: {}, label: {
Text("Numerical Target: \(numTarget)")
})
Picker(selection: $numUnitIndex, label: Text("Numerical Unit: \(numUnit)")) {
ForEach(0 ..< units.count) {
Text(self.units[$0]).tag($0).foregroundColor(.blue)//.listRowInsets(EdgeInsets())
}
}.pickerStyle(MenuPickerStyle())
Button(action: {}, label: {
Text("Start date: \(startDate)")
})
Button(action: {}, label: {
Text("End date: \(endDate)")
})
Button(action: {}, label: {
Text("Category: \(category)")
})
Spacer()
}.onAppear() {
setPickerValue()
}
.navigationBarTitleDisplayMode(.inline)
.navigationTitle("Goal Details")
.toolbar {
Button("Add Step") {
print("Help tapped!")
}
}
Text("Steps for this goal").background(Color.black).font(.system(size: 20))
}
}
}
struct GoalDetailsView_Previews: PreviewProvider {
static var previews: some View {
GoalDetailsView(id: "", authorId: "", name: "", description: "", startDate: "", endDate: "", numTarget: "", numUnit: "", category: "")
}
}
When you're placing more that one item inside NavigationView you need to specify container(VStack/HStack/ZStack) explicitly, like this:
NavigationView {
VStack {
List {
// content
}
Text("Steps for this goal").font(.system(size: 20))
}
}
Generally speaking, screen will be split into sections for each NavigationView sibling up to a system specific limit. For iOS this limit is 1, which makes all other views disappear, on iPadOS and macOS the limit is higher
I found strange behavior in SwiftUI.
The sheet shows empty text when I tap a list column first time.
It seems correct after second time.
Would you help me?
import SwiftUI
let fruits: [String] = [
"Apple",
"Banana",
"Orange",
]
struct ContentView: View {
#State var isShowintSheet = false
#State var selected: String = ""
var body: some View {
NavigationView {
List(fruits, id: \.self) { fruit in
Button(action: {
selected = fruit
isShowintSheet = true
}) {
Text(fruit)
}
}
}
.sheet(isPresented: $isShowintSheet, content: {
Text(selected)
})
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
list
first tap
after second tap
Use .sheet(item:) instead. Here is fixed code.
Verified with Xcode 12.1 / iOS 14.1
struct ContentView: View {
#State var selected: String?
var body: some View {
NavigationView {
List(fruits, id: \.self) { fruit in
Button(action: {
selected = fruit
}) {
Text(fruit)
}
}
}
.sheet(item: $selected, content: { item in
Text(item)
})
}
}
extension String: Identifiable {
public var id: String { self }
}
Thank you, Omid.
I changed my code from Asperi's code using #State like this.
import SwiftUI
struct Fruit: Identifiable, Hashable {
var name: String
var id = UUID()
}
let fruits: [Fruit] = [
Fruit(name: "Apple"),
Fruit(name: "Banana"),
Fruit(name: "Orange"),
]
struct ContentView: View {
#State var selected: Fruit?
var body: some View {
NavigationView {
List(fruits, id: \.self) { fruit in
Button(action: {
selected = fruit
}) {
Text(fruit.name)
}
}
}
.sheet(item: $selected, content: { item in
Text(item.name)
})
}
}
I'm trying to update arrays item with typed new value into Textfield, but List is not updated with edited value.
My Code is:
Model:
struct WalletItem: Identifiable{
let id = UUID()
var name:String
var cardNumber:String
var type:String
var cvc:String
let pin:String
var dateOfExpiry:String
}
ModelView:
class Wallet: ObservableObject{
#Published var wallets = [
WalletItem(name: "BSB", cardNumber: "123456789", type: "master card", cvc: "1234", pin: "1234", dateOfExpiry: "2016-06-29"),
WalletItem(name: "Alpha bank", cardNumber: "123456789", type: "master card", cvc: "1234", pin: "1234", dateOfExpiry: "2017-03-12"),
WalletItem(name: "MTŠ‘", cardNumber: "123456789", type: "master card", cvc: "1234", pin: "1234", dateOfExpiry: "2020-11-12"),
]
}
First View:
struct WalletListView: View {
// Properties
// ==========
#ObservedObject var wallet = Wallet()
#State var isNewItemSheetIsVisible = false
var body: some View {
NavigationView {
List(wallet.wallets) { walletItem in
NavigationLink(destination: EditWalletItem(walletItem: walletItem)){
Text(walletItem.name)
}
}
.navigationBarTitle("Cards", displayMode: .inline)
.navigationBarItems(
leading: Button(action: { self.isNewItemSheetIsVisible = true
}) {
HStack {
Image(systemName: "plus.circle.fill")
Text("Add item")
}
}
)
}
.sheet(isPresented: $isNewItemSheetIsVisible) {
NewWalletItem(wallet: self.wallet)
}
}
}
and Secondary View:
struct EditWalletItem: View {
#State var walletItem: WalletItem
#Environment(\.presentationMode) var presentationMode
var body: some View {
Form{
Section(header: Text("Card Name")){
TextField("", text: $walletItem.name)
}
}
.navigationBarItems(leading:
Button(action: {
self.presentationMode.wrappedValue.dismiss()
})
{
Text("Back")
}, trailing:
Button(action: {
self.presentationMode.wrappedValue.dismiss()
})
{
Text("Save")
})
}
}
P.S: If I use #Binding instead of the #State I've got an error in the first view: Initializer init(_:) requires that Binding<String> conform to StringProtocol
Here are modified parts (tested & works with Xcode 11.2 / iOS 13.2):
Sure over binding
struct EditWalletItem: View {
#Binding var walletItem: WalletItem
Place to pass it
List(Array(wallet.wallets.enumerated()), id: .element.id) { (i, walletItem) in
NavigationLink(destination: EditWalletItem(walletItem: self.$wallet.wallets[i])){
Text(walletItem.name)
}
}
ForEach(Array(list.enumerated())) will only work correctly if the list is an Array but not for an ArraySlice, and it has the downside of copying the list.
A better approach is using a .indexed() helper:
struct IndexedCollection<Base: RandomAccessCollection>: RandomAccessCollection {
typealias Index = Base.Index
typealias Element = (index: Index, element: Base.Element)
let base: Base
var startIndex: Index { self.base.startIndex }
var endIndex: Index { self.base.endIndex }
func index(after i: Index) -> Index {
self.base.index(after: i)
}
func index(before i: Index) -> Index {
self.base.index(before: i)
}
func index(_ i: Index, offsetBy distance: Int) -> Index {
self.base.index(i, offsetBy: distance)
}
subscript(position: Index) -> Element {
(index: position, element: self.base[position])
}
}
extension RandomAccessCollection {
func indexed() -> IndexedCollection<Self> {
IndexedCollection(base: self)
}
}
Example:
// SwiftUIPlayground
// https://github.com/ralfebert/SwiftUIPlayground/
import Foundation
import SwiftUI
struct Position {
var id = UUID()
var count: Int
var name: String
}
class BookingModel: ObservableObject {
#Published var positions: [Position]
init(positions: [Position] = []) {
self.positions = positions
}
}
struct EditableListExample: View {
#ObservedObject var bookingModel = BookingModel(
positions: [
Position(count: 1, name: "Candy"),
Position(count: 0, name: "Bread"),
]
)
var body: some View {
// >>> Passing a binding into an Array via index:
List(bookingModel.positions.indexed(), id: \.element.id) { i, _ in
PositionRowView(position: self.$bookingModel.positions[i])
}
}
}
struct PositionRowView: View {
#Binding var position: Position
var body: some View {
Stepper(
value: $position.count,
label: {
Text("\(position.count)x \(position.name)")
}
)
}
}
struct EditableListExample_Previews: PreviewProvider {
static var previews: some View {
EditableListExample()
}
}
See also:
How does the Apple-suggested .indexed() property work in a ForEach?
I want a list with rows, with each row having 2 Textfields inside of it. Those rows should be saved in an array, so that I can use the data in an other view for further functions. If the text in the Textfield is changed, the text should be saved inside the right entry in the array.
You also can add new rows to the list via a button, which should also change the array for the rows.
The goal is to have a list of key value pairs, each one editable and those entries getting saved with the current text.
Could someone help me and/or give me hint for fixing this problem?
So far I have tried something like this:
// the array of list entries
#State var list: [KeyValue] = [KeyValue()]
// the List inside of a VStack
List(list) { entry in
KeyValueRow(list.$key, list.$value)
}
// the single item
struct KeyValue: Identifiable {
var id = UUID()
#State var key = ""
#State var value = ""
}
// one row in the list with view elements
struct KeyValueRow: View {
var keyBinding: Binding<String>
var valueBinding: Binding<String>
init(_ keyBinding: Binding<String>, _ valueBinding: Binding<String>){
self.keyBinding = keyBinding
self.valueBinding = valueBinding
}
var body: some View {
HStack() {
TextField("key", text: keyBinding)
Spacer()
TextField("value", text: valueBinding)
Spacer()
}
}
}
Also, about the button for adding new entries.
Problem is that if I do the following, my list in the view goes blank and everything is empty again
(maybe related: SwiftUI TextField inside ListView goes blank after filtering list items ?)
Button("Add", action: {
self.list.append(KeyValue())
})
I am not sure what the best practice is keep a view up to date with state in an array like this, but here is one approach to make it work.
For the models, I added a list class that conforms to Observable object, and each KeyValue item alerts it on changes:
class KeyValueList: ObservableObject {
#Published var items = [KeyValue]()
func update() {
self.objectWillChange.send()
}
func addItem() {
self.items.append(KeyValue(parent: self))
}
}
class KeyValue: Identifiable {
init(parent: KeyValueList) {
self.parent = parent
}
let id = UUID()
private let parent: KeyValueList
var key = "" {
didSet { self.parent.update() }
}
var value = "" {
didSet { self.parent.update() }
}
}
Then I was able to simply the row view to just keep a single piece of state:
struct KeyValueRow: View {
#State var item: KeyValue
var body: some View {
HStack() {
TextField("key", text: $item.key)
Spacer()
TextField("value", text: $item.value)
Spacer()
}
}
}
And for the list view:
struct TextFieldList: View {
#ObservedObject var list = KeyValueList()
var body: some View {
VStack {
List(list.items) { item in
HStack {
KeyValueRow(item: item)
Text(item.key)
}
}
Button("Add", action: {
self.list.addItem()
})
}
}
}
I just threw an extra Text in there for testing to see it update live.
I did not run into the Add button blanking the view as you described. Does this solve that issue for you as well?
Working code example for iOS 15
In SwiftUI, Apple recommends passing the binding directly into the List constructor and using a #Binding in the ViewBuilder block to iterate through with each element.
Apple recommends this approach over using the Indices to iterate over the collection since this doesn't reload the whole list every time a TextField value changes (better efficiency).
The new syntax is also back-deployable to previous releases of SwiftUI apps.
struct ContentView: View {
#State var directions: [Direction] = [
Direction(symbol: "car", color: .mint, text: "Drive to SFO"),
Direction(symbol: "airplane", color: .blue, text: "Fly to SJC"),
Direction(symbol: "tram", color: .purple, text: "Ride to Cupertino"),
Direction(symbol: "bicycle", color: .orange, text: "Bike to Apple Park"),
Direction(symbol: "figure.walk", color: .green, text: "Walk to pond"),
Direction(symbol: "lifepreserver", color: .blue, text: "Swim to the center"),
Direction(symbol: "drop", color: .indigo, text: "Dive to secret airlock"),
Direction(symbol: "tram.tunnel.fill", color: .brown, text: "Ride through underground tunnels"),
Direction(symbol: "key", color: .red, text: "Enter door code:"),
]
var body: some View {
NavigationView {
List($directions) { $direction in
Label {
TextField("Instructions", text: $direction.text)
}
}
.listStyle(.sidebar)
.navigationTitle("Secret Hideout")
}
}
}
struct Direction: Identifiable {
var id = UUID()
var symbol: String
var color: Color
var text: String
}
No need to mess up with classes, Observable, Identifiable. You can do it all with structs.
Note, that version below will do fine for insertions, but fail if you try to delete array elements:
import SwiftUI
// the single item
struct KeyValue {
var key: String
var value: String
}
struct ContentView: View {
#State var boolArr: [KeyValue] = [KeyValue(key: "key1", value: "Value1"), KeyValue(key: "key2", value: "Value2"), KeyValue(key: "key3", value: "Value3"), KeyValue(key: "key4", value: "Value4")]
var body: some View {
NavigationView {
// id: \.self is obligatory if you need to insert
List(boolArr.indices, id: \.self) { idx in
HStack() {
TextField("key", text: self.$boolArr[idx].key)
Spacer()
TextField("value", text: self.$boolArr[idx].value)
Spacer()
}
}
.navigationBarItems(leading:
Button(action: {
self.boolArr.append(KeyValue(key: "key\(UInt.random(in: 0...100))", value: "value\(UInt.random(in: 0...100))"))
print(self.boolArr)
})
{ Text("Add") }
, trailing:
Button(action: {
self.boolArr.removeLast() // causes "Index out of range" error
print(self.boolArr)
})
{ Text("Remove") })
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Update:
A little trick to make it work with deletions as well.
import SwiftUI
// the single item
struct KeyValue {
var key: String
var value: String
}
struct KeyValueView: View {
#Binding var model: KeyValue
var body: some View {
HStack() {
TextField("Key", text: $model.key)
Spacer()
TextField("Value", text: $model.value)
Spacer()
}
}
}
struct ContentView: View {
#State var kvArr: [KeyValue] = [KeyValue(key: "key1", value: "Value1"), KeyValue(key: "key2", value: "Value2"), KeyValue(key: "key3", value: "Value3"), KeyValue(key: "key4", value: "Value4")]
var body: some View {
NavigationView {
List(kvArr.indices, id: \.self) { i in
KeyValueView(model: Binding(
get: {
return self.kvArr[i]
},
set: { (newValue) in
self.kvArr[i] = newValue
}))
}
.navigationBarItems(leading:
Button(action: {
self.kvArr.append(KeyValue(key: "key\(UInt.random(in: 0...100))", value: "value\(UInt.random(in: 0...100))"))
print(self.kvArr)
})
{ Text("Add") }
, trailing:
Button(action: {
self.kvArr.removeLast() // Works like a charm
print(self.kvArr)
})
{ Text("Remove") })
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Swift 5.5
This version of swift enables one line code for this by passing the bindable item directly from the array.
struct DirectionsList: View {
#Binding var directions: [Direction]
var body: some View {
List($directions) { $direction in
Label {
TextField("Instructions", text: $direction.text)
} icon: {
DirectionsIcon(direction)
}
}
}
}
Trying to make a modal that's similar to the "Create Event" modal in Apple's Calendar app. I've got my modal successfully showing using the following code in a parent NavigationView:
.navigationBarItems(trailing:
Button(action: {
self.isModal = true
}) {
Image(systemName: "plus").sheet(isPresented: $isModal, content: {
EventCreate(showModal: self.$isModal)
})
}
)
The modal shows successfully, but I can't get a NavigationBar to show in the modal, which looks like this:
struct EventCreate: View {
#Binding var showModal: Bool
#State var event = Event(id: 0, title: "", description: "", location: "", start: Date(), end: Date(), cancelled: false, public_occurrence: false, created: "", last_updated: "", guests: -1)
var body: some View {
NavigationView {
Form{
Section {
TextField("Title", text: $event.title)
TextField("Location", text: $event.location)
}
Section {
DatePicker(selection: $event.start, label: { Text("Start") })
DatePicker(selection: $event.end, label: { Text("End") })
}
}
}
.navigationBarTitle(Text("Create Event"), displayMode: .inline)
.navigationBarItems(leading:
Button("Close") {
self.showModal = false
})
}
}
The app builds, and the Form is displayed, but the NavigationView doesn't:
How can I make this show? Or is there another view I should be using instead of NavigationView
You need to put navigationBarTitle and navigationBarItems modifier inside the NavigationView, not outside it. These modifiers must be placed on the view that you are embedding, in your case the Form
struct EventCreate: View {
#Binding var showModal: Bool
#State var event = Event(id: 0, title: "", description: "", location: "", start: Date(), end: Date(), cancelled: false, public_occurrence: false, created: "", last_updated: "", guests: -1)
var body: some View {
NavigationView {
Form{
Section {
TextField("Title", text: $event.title)
TextField("Location", text: $event.location)
}
Section {
DatePicker(selection: $event.start, label: { Text("Start") })
DatePicker(selection: $event.end, label: { Text("End") })
}
}
.navigationBarTitle(Text("Create Event"), displayMode: .inline)
.navigationBarItems(leading:
Button("Close") {
self.showModal = false
})
}
}
}
This article by HackingWithSwift shows the correct placement.