SwiftUI 2.0 Cheat Sheet

SwiftUI Cheat Sheet
- Table of Contents
Resource
UIKit equivalent in SwiftUI
View
- Text
- Label
- TextEditor
- Image
- Shape
- ProgressView
- Map
Layout
- Background
- VStack
- HStack
- ZStack
- LazyVStack
- LazyHStack
- LazyVGrid
- LazyHGrid
Input
- Toggle
- Button
- TextField
- Slider
- Date Picker
- Picker
- Stepper
- Tap
- Gesture
- OnChange
List
Containers
Alerts and Action Sheets
Navigation
Work with UIKit
- Navigate to ViewController
- Use UIKit and SwiftUI Views Together

Resource

UIKit equivalent in SwiftUI

UIKit	SwiftUI
UILabel	Text & Label
UIImageView	Image
UITextField	TextField
UITextView	TextEditor
UISwitch	Toggle
UISlider	Slider
UIButton	Button
UITableView	List
UICollectionView	LazyVGrid / LazyHGrid
UINavigationController	NavigationView
UITabBarController	TabView
UIAlertController with style .alert	Alert
UIAlertController with style .actionSheet	ActionSheet
UIStackView with horizontal axis	HStack / LazyHStack
UIStackView with vertical axis	VStack / LazyVStack
UISegmentedControl	Picker
UIStepper	Stepper
UIDatePicker	DatePicker
NSAttributedString	No equivalent (use Text)
MapKit	Map
UIProgressView	ProgressView

View

Text

To show a text in UI simply write:

Text("Hello World")

Screenshot

To add style

Text("Hello World")
    .font(.largeTitle)
    .foregroundColor(Color.green)
    .lineSpacing(50)
    .lineLimit(nil)
    .padding()

Screenshot

To format text inside text view

static let dateFormatter: DateFormatter = {
    let formatter = DateFormatter()
    formatter.dateStyle = .long
    return formatter
}()

var now = Date()
var body: some View {
    Text("Task due date: \(now, formatter: Self.dateFormatter)")
}

Screenshot

Label

Labels are a much-needed addition in the latest SwiftUI iteration. They let you set icons alongside text with the following line of code.

Label("SwiftUI CheatSheet 2.0", systemImage: "up.icloud")

It's possible to set URL, upon clicking which will redirect to browser.

Link("Click me",destination: URL(string: "your_url")!)

TextEditor

Multi-line scrollable UITextViews natively in SwiftUI

TextEditor(text: $currentText)
                .onChange(of: clearText) { value in
                    if clearText {
                        currentText = ""
                    }
                }

Map

MapKit natively in SwiftUI

Map(mapRect:interactionModes:showsUserLocation: userTrackingMode:

Image

To show image

Image("hello_world") //image name is hello_world

Screenshot

To use system icon

Image(systemName: "cloud.heavyrain.fill")

Screenshot

you can add style to system icon set

Image(systemName: "cloud.heavyrain.fill")
    .foregroundColor(.red)
    .font(.largeTitle)

Screenshot

Add style to Image

Image("hello_world")
    .resizable() //it will sized so that it fills all the available space
    .aspectRatio(contentMode: .fill)
    .padding(.bottom)

Screenshot

Shape

To create Rectangle

Rectangle()
    .fill(Color.red)
    .frame(width: 200, height: 200)

Screenshot

To create circle

Circle()
    .fill(Color.blue)
    .frame(width: 50, height: 50)

Screenshot

ProgressView

To show a ProgressView

ProgressView("Text", value: 10, total: 100)

Layout

Background

To use image as a background

Text("Hello World")
    .font(.largeTitle)
    .background(
        Image("hello_world")
            .resizable()
            .frame(width: 100, height: 100)
    )

Screenshot

Gradient background

Text("Hello World")
    .background(
        LinearGradient(
            gradient: Gradient(colors: [.white, .red, .black]), 
            startPoint: .leading, 
            endPoint: .trailing
        ),
        cornerRadius: 0
    )

Screenshot

VStack

Shows child view vertically

VStack {
    Text("Hello")
    Text("World")
}

Screenshot

Styling

VStack(alignment: .leading, spacing: 20) {
    Text("Hello")
    Divider()
    Text("World")
}

Screenshot

HStack

Shows child view horizontally

HStack {
    Text("Hello")
    Text("World")
}

Screenshot

ZStack

To create overlapping content use ZStack

ZStack() {
    Image("hello_world")
    Text("Hello World")
        .font(.largeTitle)
        .background(Color.black)
        .foregroundColor(.white)
}

Screenshot

LazyVStack

It loads content as and when it’s needed thus improving performance

  ScrollView(.horizontal) {
           LazyVStack(spacing: 10) {
                ForEach(0..<1000) { index in
                    Text("\(index)")
                            .frame(width: 100, height: 200)
                            .border(Color.gray.opacity(0.5), width: 0.5)
                            .background(Color.blue)
                            .cornerRadius(6)
                }
            }
            .padding(.leading, 10)
        }

LazyHStack

It loads content as and when it’s needed thus improving performance

  ScrollView(.horizontal) {
            LazyHStack(spacing: 10) {
                ForEach(0..<1000) { index in
                    Text("\(index)")
                            .frame(width: 100, height: 200)
                            .border(Color.gray.opacity(0.5), width: 0.5)
                            .background(Color.blue)
                            .cornerRadius(6)
                }
            }
            .padding(.leading, 10)
        }

LazyVGrid

A containers for grid-based layouts that let you set child views vertically in LazyVGrid. Each element of a SwiftUI grid is a GridItem. We can set the alignments, spacing, and size of the GridItem

struct ContentView: View {
    
    let colors: [Color] = [.red, .green, .yellow, .blue]
    
    var columns: [GridItem] =
        Array(repeating: .init(.flexible(), alignment: .center), count: 3)
    
    var body: some View {
        ScrollView {
            LazyVGrid(columns: columns, spacing: 10) {
                ForEach(0...100, id: \.self) { index in
                    Text("Tab \(index)")
                        .frame(width: 110, height: 200)
                        .background(colors[index % colors.count])
                    .cornerRadius(8)
                }
            }
        }
    }
}

LazyHGrid

A containers for grid-based layouts that let you set child views horizontally in LazyHGrid

struct ContentView: View {
    
    let colors: [Color] = [.red, .green, .yellow, .blue]
    
    var columns: [GridItem] =
        Array(repeating: .init(.flexible(), alignment: .center), count: 3)
    
    var body: some View {
        ScrollView {
            LazyHGrid(columns: columns, spacing: 10) {
                ForEach(0...100, id: \.self) { index in
                    Text("Tab \(index)")
                        .frame(width: 110, height: 200)
                        .background(colors[index % colors.count])
                    .cornerRadius(8)
                }
            }
        }
    }
}

Input

Toggle

Toggle lets users move between true and false states

@State var isShowing = true //state

Toggle(isOn: $isShowing) {
    Text("Hello World")
}.padding()

Screenshot

Button

To create button

Button(
    action: {
        // do something
    },
    label: { Text("Click Me") }
)

Screenshot

To create image Button

Button(
    action: {
        // do something
    },
    label: { Image("hello_world") }
)

TextField

It heavily relies in state, simply create a state and pass it as it will bind to it

@State var fullName: String = "Joe" //create State

TextField($fullName) // passing it to bind
    .textFieldStyle(.roundedBorder) // adds border

Screenshot

To create secure TextField

@State var password: String = "" // create State

SecureField($password) // passing it to bind
    .textFieldStyle(.roundedBorder) // adds border

Screenshot

Slider

@State var value: Double = 0 // create State
    
Slider(value: $value, from: -100, through: 100, by: 1)

Screenshot

Date Picker

@State var selectedDate = Date()
DatePicker(
    $selectedDate,
    maximumDate: Date(),
    displayedComponents: .date
)

Screenshot

Picker

@State var favoriteColor = 0
var colors = ["Red", "Green", "Blue"]

Picker("Favorite Color", selection: $favoriteColor) {
    ForEach(0 ..< colors.count) { index in
        Text(self.colors[index])
            .tag(index)
    }
}
.pickerStyle(SegmentedPickerStyle())

Screenshot

Stepper

@State var count:Int = 0

Stepper(
    onIncrement: { self.count += 1 }, 
    onDecrement: { self.count -= 1 }, 
    label: { Text("Count is \(count)") }
)

@State var count:Int = 0

Stepper(value: $count, in: 1...10) {
    Text("Count is \(count)")
}

@State private var temperature = 0.0

Stepper(value: $temperature, in: 0...100.0, step: 0.5) {
                Text("Temperature is \(temperature, specifier:"%g")")
            }

Tap

For single tap

Text("Tap me!")
    .onTapGesture {
        print("Tapped!")
    }

For double tap

Text("Tap me!")
    .onTapGesture(count: 2) {
        print("Tapped!")
    }

Screenshot

Gesture

Gesture like TapGesture, LongPressGesture, DragGesture

Text("Tap")
    .gesture(
        TapGesture()
            .onEnded { _ in
                // do something
            }
    )

Text("Drag Me")
    .gesture(
        DragGesture(minimumDistance: 50)
            .onEnded { _ in
                // do something
            }
    )

Text("Long Press")
    .gesture(
        LongPressGesture(minimumDuration: 2)
            .onEnded { _ in
                // do something
            }
    )

OnChange

onChange is a new view modifier that’s available across all SwiftUI views. It lets you listen to state changes and perform actions on a view accordingly.

 TextEditor(text: $currentText)
                .onChange(of: clearText) { value in
                    if clearText{
                        currentText = ""
                    }
                }

List

To create static scrollable List

List {
    Text("Hello world")
    Text("Hello world")
    Text("Hello world")
}

Screenshot

To create dynamic List

let names = ["Thanos", "Iron man", "Ant man"]
List(names, id: \.self) { name in
    Text(name)
}

To add section

List {
    Section(header: Text("Good Hero")) {
        Text("Thanos")
    }

    Section(header: Text("Bad Heros")) {
        Text("Iron man")
    }
}

Screenshot

To make it grouped add .listStyle(GroupedListStyle())

List {
    Section(header: Text("Good Hero")) {
        Text("Thanos")
    }

    Section(header: Text("Bad Heros")) {
        Text("Iron man")
    }
}.listStyle(GroupedListStyle())

Screenshot

To add a footer to a section

List {
    Section(header: Text("Good Heros"), footer: Text("Powerful")){
        Text("Thanos")
    }
    Section(header: Text("Bad Heros"), footer: Text("Not as Powerful")){
        Text("Iron Man")
    }
}.listStyle(GroupedListStyle())

Screenshot

Containers

NavigationView

NavigationView is more/less like UINavigationController, It handles navigation between views, shows title, places navigation bar on top.

NavigationView {
    Text("Hello")
        .navigationBarTitle(Text("World"), displayMode: .inline)
}

Screenshot

For large title use .large

Add bar items to NavigationView

NavigationView {
    Text("Hello")
        .navigationBarTitle(Text("World"), displayMode: .inline)
        .navigationBarItems(
            trailing:
                Button(
                    action: { print("Going to Setting") },
                    label: { Text("Setting") }
                )
        )
}

Screenshot

TabView

TabView creates a container similar to UITabBarController with radio-style selection control which determines which View is presented.

@State private var selection = 0

TabView(selection: $selection) {
    Text("View A")
        .font(.title)
        .tabItemLabel(Text("View A")
            .font(.caption))
        .tag(0)
    Text("View B")
        .font(.title)
        .tabItemLabel(Text("View B")
            .font(.caption))
        .tag(1)
    Text("View C")
        .font(.title)
        .tabItemLabel(Text("View C")
            .font(.caption))
        .tag(2)
}

Screenshot

Group

Group creates several views to act as one, also to avoid Stack's 10 View maximum limit.

VStack {
    Group {
        Text("Hello")
        Text("Hello")
        Text("Hello")
    }
    Group {
        Text("Hello")
        Text("Hello")
    }
}

Screenshot

Alerts and Action Sheets

To Show an Alert

Alert(
    title: Text("Title"), 
    message: Text("message"), 
    dismissButton: .default(Text("Ok!"))
)

To Show Action Sheet

ActionSheet(
    title: Text("Title"), 
    message: Text("Message"), 
    buttons: [
        .default(Text("Ok!"), action: { print("hello") })
    ]
)

Navigation

Navigate via NavigationLink

NavigationView {
    NavigationLink(destination: SecondView()) {
        Text("Show")
    }.navigationBarTitle(Text("First View"))
}

Screenshot

Navigate via tap on List Item

let names = ["Thanos", "Iron man", "Ant man"]
List(names, id: \.self) { name in
    NavigationLink(destination: HeroView(name: name)) {
        Text(name)
    }
}

Work with UIKit

Navigate to ViewController

It's possible to work with UIKit components from SwiftUI or call SwiftUI views as View Controllers from UIKit.

Let's say you have a View Controller named SuperVillainViewController and want to call it from a SwiftUI view, to do that ViewController needs to implement UIViewControllerRepresentable:

struct SuperVillainViewController: UIViewControllerRepresentable {
    var controllers: [UIViewController]
    func makeUIViewcontroller(context: Context) -> SuperVillainViewController {
        // you could have a custom constructor here, I'm just keeping it simple
        let vc = SuperVillainViewController()
        return vc
    }
}

Now you can use it like

NavigationLink(destination: SuperVillainViewController()) {
    Text("Click")
}

Use UIKit and SwiftUI Views Together

To use UIView subclasses from within SwiftUI, you wrap the other view in a SwiftUI view that conforms to the UIViewRepresentable protocol. (Reference)

as example

import SwiftUI
import MapKit

struct MapView: UIViewRepresentable {
    func makeUIView(context: Context) -> MKMapView {
        MKMapView(frame: .zero)
    }

    func updateUIView(_ view: MKMapView, context: Context) {
        let coordinate = CLLocationCoordinate2D(
            latitude: 34.011286, 
            longitude: -116.166868
        )
        let span = MKCoordinateSpan(latitudeDelta: 2.0, longitudeDelta: 2.0)
        let region = MKCoordinateRegion(center: coordinate, span: span)
        view.setRegion(region, animated: true)
    }
}

struct MapView_Preview: PreviewProvider {
    static var previews: some View {
        MapView()
    }
}

Grouped section with header and footer text

Apple is using the grouped sections a lot in their iOS setting app. Do the sections also provide a footer parameter?

In most of The iOS Interface the header text is uppercase and the footer small and gray-ish. Will this be handled by SwiftUI in the future?

Thank you for building this reference!

opened by m5o 4
Fix several code style & spacing issues + 'UIKit' typos

As many developers will use this cheat sheet in the future, I think we should make sure to be good citizens and have good and consistent code styling in the README. I also fixed the most annoying typo for me as a reader, which was the multiple appearance of UIKIT which is incorrect. I don't even know what the IT at the end could be abbreviations of (UI abbreviates User Interface).

The code should be much more readable and consistent once this is merged.

opened by Jeehut 3
Update Documentation
Rename TabbedView to TabView

SegmentedControl has beed deprecated in favor of Picker.pickerStyle(SegmentedPickerStyle())

PresentationButton has beed deprecated in favor of .sheet(isPresented: Bool)
opened by yuzushioh 0
Downscale images to 50%

I think you should just downscale the images uploaded in the repository (using preview, you can downscale using a percentage)

Originally posted by @tbaranes in https://github.com/SimpleBoilerplates/SwiftUI-Cheat-Sheet/pull/12#issuecomment-503043823

opened by AkdM 0
SuperVillainViewController example
The example does not seem correct. At no point are you instantiating a view controller, as the line

let vc = SuperVillainViewController()

is just creating an instance of the enclosing struct.
opened by avi-kik 2