Chapter 1: Views

October 25, 2019 · View on GitHub

SwiftUI

Better apps. Less code.
SwiftUI is an innovative, exceptionally simple way to build user interfaces across all Apple platforms with the power of Swift. Build user interfaces for any Apple device using just one set of tools and APIs.
With a declarative Swift syntax that’s easy to read and natural to write, SwiftUI works seamlessly with new Xcode design tools to keep your code and design perfectly in sync.
Automatic support for Dynamic Type, Dark Mode, localization, and accessibility means your first line of SwiftUI code is already the most powerful UI code you’ve ever written.

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SwiftUI shortcuts
Command + Option + Enter : Toggle the preview window
Command + Option + P : Refresh the preview window

This page has 86 SwiftUI examples, and records the screenshots of all results here, hope to be helpful to you.
All examples are based on Xcode 11.1 for now.
Xcode 11 link: https://developer.apple.com/download/

ios development 426 tutorials on the App Store:
https://apps.apple.com/us/app/ios-development-426-tutorials/id1225080698?l=en

Navigator：

Chapter 1: Views
Chatper 2: Animation
Chapter 3: Gesture
Chapter 4: Layout
Chapter 5: DataFlow
Chapter 6: More
Chapter 6: Projects by SwiftUI
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Chapter 1: Views

1、How to create a SwiftUI project:

1、Open Xcode, choose File > New > Project.
2、Choose Single View App template and click Next.
3、Select SwiftUI checkbox, and then click Next.
4、Here you get the SwiftUI project

5. Project navigator

File name	Comment
AppDelegate.swift	Override point for customization after application launch.
SceneDelegate.swift	Use func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
ContentView.swift	The initial interface of the project, the visual views on the user interface can be placed in this file.
Assets.xcassets	Here you can place images, colors or other resources in this folder.
LaunchScreen.storyboard	Used to configure what is displayed during project startup.
Info.plist	The configuration property file of the project, including the product name, version number, build number, Bundle Identifier and other items.

6、Editor:

SwiftUI uses a declarative syntax so you can simply state what your user interface should do.
For example, you can write that you want a list of items consisting of text fields, then describe alignment, font, and color for each field.
Your code is simpler and easier to read than ever before, saving you time and maintenance.

7、ContentView.swift:

//import SwiftUI framework
import SwiftUI 		             

//By default, SwiftUI view files declare two structures. 
//The first structure conforms to the View protocol and describes the view’s content and layout. 
struct ContentView: View {		 
//
    var body: some View {
    	//Show something on the screen.
        Text("Hello World")
    }
}

//Running when debugging
#if DEBUG
//The second structure declares a preview for that view.
struct ContentView_Previews: PreviewProvider {
//overrid the previews of PreviewProvider protocol
    static var previews: some View {
    	//Show the content on the preview window
        ContentView()
    }
}
#endif

8、SceneDelegate.swift

//Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

        if let windowScene = scene as? UIWindowScene {
	    //Create a new window
            let window = UIWindow(windowScene: windowScene)
	    // Initialize a new UIHostingController, and set it as the rootViewController of the window.
            window.rootViewController = UIHostingController(rootView: ContentView())
	    // assign the window object to the window of the application
            self.window = window
	    // show the window
            window.makeKeyAndVisible()
        }
    }

2: Text-BasicStyle

A view that displays one or more lines of read-only text.
Code:

VStack{
    //Basic style
    Text("www.hdjc8.com")
	.bold()

    Text("www.hdjc8.com")
	.italic()

    Text("www.hdjc8.com")
	.underline()

    Text("www.hdjc8.com")
	.underline(true, color: .orange)

    Text("www.hdjc8.com")
	.strikethrough()

    Text("www.hdjc8.com")
	.strikethrough(true, color: .orange)

    Text("www.hdjc8.com")
	.foregroundColor(Color.orange)

    Text("www.hdjc8.com")
	.baselineOffset(CGFloat(5.0))
	.background(Color.orange)

     Text("www.hdjc8.com")
	 .background(Image("Picture"), alignment: .bottom)

    //Font
    VStack{
	Text("www.hdjc8.com")
	    .font(.footnote)

	Text("www.hdjc8.com")
	    .font(.system(size: 36))

	Text("www.hdjc8.com")
	    .font(.system(.title, design: .monospaced))

	Text("www.hdjc8.com")
	    .font(.custom("BradleyHandITCTT-Bold", size: 36))

	Text("www.hdjc8.com")
	    .fontWeight(Font.Weight.heavy)

	Text("www.hdjc8.com")
	    .fontWeight(Font.Weight.ultraLight)

    }
}

View the result

3: Text-Paragraph

Code:

VStack{

    Text("www.hdjc8.com")

    Text("www.hdjc8.com")
	.tracking(10)

    Text("www.hdjc8.com")
	.kerning(10)

    Text("www.hdjc8.com")
	.blur(radius: 1)

    Text("SwiftUI is an innovative, exceptionally simple way to build user interfaces across all Apple platforms with the power of Swift.")
	.lineSpacing(20)
//                .lineLimit(1)
	.lineLimit(nil)

    Text("www.hdjc8.com")
	.offset(x: 40, y: 0)

    Text("www.hdjc8.com")
	.frame(width: 200, height: 80, alignment: .bottomTrailing)
	.background(Color.orange)

    VStack{
	Text("www.hdjc8.com2")
	    .position(x: 50, y: 50)
	    .frame(width: 300, height: 100, alignment: .bottomTrailing)
	    .background(Color.orange)

	Text("Interactive\ntutorials\nfor\nXcode!")
	    .multilineTextAlignment(.center)
	    .lineLimit(4)

	Text("Hello\nInteractive Tutorials!").multilineTextAlignment(.leading)
    }

}

View the result

4: Text-Padding

br/> Code:

VStack{
    Text("www.hdjc8.com")
	.background(Color.black)
	.foregroundColor(.white)
	.padding(20)

    Text("www.hdjc8.com")
	.padding()
	.background(Color.black)
	.foregroundColor(.white)

    Text("Swift User Interface")
	.font(.largeTitle)
	.foregroundColor(.black)
	.padding(15)
	.background(Color.yellow)
	.padding(15)
	.background(Color.orange)
	.padding(10)
	.background(Color.red)
}

View the result

5: Text-FullScreen

Code:

Text("Hello World")
    .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
    .background(Color.orange)
    .font(.largeTitle)
    .edgesIgnoringSafeArea(.all)

View the result

6: Text-DateFormatter

Code:

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

var body: some View {

Text("The time is: \(now, formatter: Self.dateFormatter)")
    .font(.title)
    .padding()

}

View the result

7: Text-Append

Code:

Text("Interactive ")
    .foregroundColor(.yellow)
    .fontWeight(.heavy)
+ Text("tutorials ")
    .foregroundColor(.orange)
    .strikethrough()
+ Text("for ")
    .foregroundColor(.red)
    .italic()
+ Text("SwiftUI")
    .foregroundColor(.purple)
    .underline()

View the result

8: TextField

A control that displays an editable text interface.
Code:

struct ContentView : View {
    
    @State var username : String
    @State var nickname : String
    
    var body: some View {
        
        VStack{
            
            Text("Your username is \(username)!")
            
            Text("Your nickname is \(nickname)!")
            
            TextField("User Name", text: $username, onEditingChanged: { (value) in
                print("onEditingChanged:\(self.username)")
            }) {
                print("onCommit:\(self.username)")
            }.textFieldStyle(RoundedBorderTextFieldStyle())
            
            TextField("Nick Name", text: $nickname)
                .textFieldStyle(RoundedBorderTextFieldStyle())
            
        }
        .padding()
        
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    
    static var previews: some View {
        ContentView(username: "", nickname: "")
    }
}
#endif

View the result

9: TextField-SecureField

A control into which the user securely enters private text.
Code:

struct ContentView : View {
    
    @State var password : String
    
    var body: some View {
        
        VStack{
            
            Text("Your password is \(password)!")
            
            SecureField("Your password", text: $password) {
                print("Your password is \(self.password)!")
            }
            .textFieldStyle(RoundedBorderTextFieldStyle())
            
        }
        .padding()
        
    }
}

View the result

10: Button

A control that performs an action when triggered.
Code:

VStack{

    Button("First button") {
	print("---First button action.")
    }

    Button(action: {
	print("---Second button action.")
    }) {
	Text("Second button")
    }

    Button(action: {
	print("---Third button action.")
    }) {
	Image(systemName: "clock")
	Text("Third button")
    }
    .foregroundColor(Color.white)
    .background(Color.orange)

    //padding for button : the tap area is wrong
    Button(action: {
	print("---padding for button.")
    }){
	Text("Default padding")
    }
    .padding()
    .background(Color.yellow)

    //padding for label : the tap area is correct!
    Button(action: {
	print("---padding for label.")
    }){
	Text("Default padding")
	    .padding()
	    .background(Color.yellow)
    }

    Button(action: {
	print("---Button with image.")
    }){
	HStack {
	    Image(systemName: "star")
	    Text("Button with image")
	}
	.padding()
	    .background(Color.yellow)
    }
    Button(action: {
	print("---modifier button")
    }){
	Text("modifier button")
	    .modifier(MyButtonStyle())
    }
}

View the result

11: Button-sheet

Code:

struct ContentView : View {

    @State var isPresented = false
    
    var body: some View {
        VStack{
            Button("Show modal") {
                self.isPresented = true
            }.sheet(isPresented: $isPresented, content: {
                MyDetailView(message: "Modal window")
            })
        }
    }
}

struct MyDetailView: View {
    let message: String

    var body: some View {
        VStack {
            Text(message)
                .font(.largeTitle)
        }
    }
}

View the result

12: Spacer

A flexible space that expands along the major axis of its containing stack layout, or on both axes if not contained in a stack.
Code:

var body: some View {
        VStack{
            HStack {
                Image(systemName: "clock")
                Spacer()
           }
           .padding()
        
           HStack {
                Image(systemName: "clock")
                Spacer()
                Text("\(Date())")
           }
           .padding()
        
            HStack {
                 Image(systemName: "clock")
                 Spacer(minLength: 50)
                 Text("\(Date())")
            }
            .padding()
        }
    }

View the result

13: Divider

When contained in a stack, the divider extends across the minor axis of the stack, or horizontally when not in a stack.
Code:

VStack{
    VStack {
	 Image(systemName: "clock")
	 Divider()
	 Text("\(Date())")
    }
    .padding()

    VStack {
	 Image(systemName: "clock")
	 Divider()
	    .background(Color.purple)
	    .scaleEffect(CGSize(width: 1, height: 10))
	 Text("\(Date())")
    }
    .padding()
}

View the result

14: Image-Basic

A view that displays an environment-dependent image.
Code:

VStack{
            
    Image("girlPicture")

    Image(systemName: "arkit")
	.foregroundColor(.orange)
	.font(.system(size: 48))

    Image("girlPicture")
	.resizable()
	.aspectRatio(contentMode: .fit)
}
.padding()

View the result

15: Image-Style

Code:

ScrollView{
     VStack{

	Image("girlPicture")
	    .border(Color.orange)

	Image("girlPicture")
	    .border(Color.orange, width: 10)

	Image("girlPicture")
	    .opacity(0.5)

	Image("girlPicture")
	    .shadow(radius: 10)

	Image("girlPicture")
	    .shadow(color: .purple, radius: 20, x: 20, y: 20)
    }
}

View the result

16: Image-Processing

Code:

ScrollView{
     VStack{
	Image("girlPicture")

	Image("girlPicture")
	    .blur(radius: CGFloat(2))

	Image("girlPicture")
	    .blur(radius: CGFloat(2), opaque: true)

	Image("girlPicture")
	    .brightness(0.2)

	Image("girlPicture")
	    .colorInvert()

	Image("girlPicture")
	    .colorMultiply(Color.yellow)

	Image("girlPicture")
	    .contrast(1.5)
    }

    VStack{
	Image("girlPicture")
	    .hueRotation(Angle.degrees(180))

	Image("girlPicture")
	    .saturation(10)

	Image("girlPicture")
	    .grayscale(5.5)

	Image("girlPicture")
	    .luminanceToAlpha()
    }
}

View the result

17: Image-Blend

Code:

VStack{
            
    Image("girlPicture")
	.blendMode(.difference)

    ZStack{
	Image("texture")
	Image("girlPicture")
	    .blendMode(.multiply)
    }
}
.padding()

View the result

18: Image-Mask

Code:

VStack{

    Image("girlPicture")
	.clipShape(Circle())

    Image("girlPicture")
	.mask(Circle())

    Image("texture")
    .resizable()
    .frame(width: 300, height: 300)
    .mask(
	Text("SWIFT UI!")
	    .font(Font.system(size: 64).bold()))

}

View the result

19: Image-Transform

Code:

ScrollView{
            
    VStack{
	Image("girlPicture")
	    .scaleEffect(0.8)

	Image("girlPicture")
	    .scaleEffect(CGSize(width: 1.2, height: 1))

	Image("girlPicture")
	    .scaleEffect(x: 1.5, y: 1, anchor: UnitPoint.bottomLeading)
    }

     VStack{

	Image("girlPicture")
	     .rotationEffect(Angle.init(degrees: 90))

	Image("girlPicture")
	    .rotationEffect(Angle.init(degrees: 30), anchor: UnitPoint.init(x: 0, y: 0))

	Image("girlPicture")
	    .rotation3DEffect(Angle.init(degrees: 30), axis: (x: CGFloat(0.1), y: CGFloat(0.1), z: CGFloat(0)))

    }
}

View the result

20: Image-Web

Code:

struct ContentView : View {
    
    @State private var remoteImage : UIImage? = nil
    let placeholderOne = UIImage(named: "Picture")
    
    var body: some View {
        Image(uiImage: self.remoteImage ?? placeholderOne!)
            .onAppear(perform: fetchRemoteImage)
    }
    
    func fetchRemoteImage()
    {
        guard let url = URL(string: "http://hdjc8.com/images/logo.png") else { return }
        URLSession.shared.dataTask(with: url){ (data, response, error) in
            if let image = UIImage(data: data!){
                self.remoteImage = image
            }
            else{
                print(error ?? "")
            }
        }.resume()
    }
}

View the result

21: Picker

A control for selecting from a set of mutually exclusive values.
Code:

struct ContentView : View {
    
     var fruits = ["Apple", "Banner", "Pear", "Watermelon"]
     var colors = [Color.blue, Color.orange, Color.red, Color.purple]
     @State private var selectedItem = 0

     var body: some View {
        VStack {
            
           Picker(selection: $selectedItem, label: Text("Fruits")) {
              ForEach(0 ..< fruits.count) {
                Text(self.fruits[\$0]).tag(\$0).foregroundColor(self.colors[\$0])
              }
           }
           Text("Your choice: ")
            + Text("\(fruits[selectedItem])").foregroundColor(self.colors[selectedItem])
        }
     }
}

View the result

22: DatePicker

A control for selecting an absolute date.
Code:

struct ContentView : View {
    var myDateFormatter: DateFormatter {
        let formatter = DateFormatter()
        formatter.dateStyle = .long
        return formatter
    }

    @State var selectedDate = Date()

    var body: some View {
        VStack {
            DatePicker(selection: $selectedDate, displayedComponents: DatePickerComponents.hourAndMinute) {
                Text("Date")
            }
            
            DatePicker(selection: $selectedDate, displayedComponents: DatePickerComponents.date) {
                Text("Date")
            }

            DatePicker(selection: $selectedDate,in: Date()...Date().advanced(by: 7*24*3600), displayedComponents: [.date, .hourAndMinute]) {
                Text("Date")
            }

            Text("Your Choice: \(selectedDate, formatter: myDateFormatter)")
        }
    }
}

View the result

23: Slider

A control for selecting a value from a bounded linear range of values.
Code:

struct ContentView : View {
    
     @State var temperature: Double = 0

       var body: some View {
           VStack {
                Slider(value: $temperature)
                Slider(value: $temperature, in: -20...40)
                Slider(value: $temperature, in: -20...40) { (item) in
                    print(item)
                }
                HStack{
                    Image(systemName: "sun.max")

                    Slider(value: $temperature, in: -20...40, step: 2) { (item) in
                        print(item)
                    }.accentColor(.pink).colorInvert()
                    
                   Image(systemName: "sun.max.fill")
                }.padding()

                Text("The temperature is \(Int(temperature)).")
           }
       }
}

View the result

24: Stepper

A control used to perform semantic increment and decrement actions.
Code:

struct ContentView : View {
    
     @State var temperature: Double = 0

       var body: some View {
        
           VStack {
                Stepper(onIncrement: {
                    self.temperature += 1
                }, onDecrement: {
                    self.temperature -= 1
                }, label: { Text("Temperature: \(Int(temperature))") })
                
                Stepper(onIncrement: {
                    self.temperature += 1
                }, onDecrement: {
                    self.temperature -= 1
                }, onEditingChanged: { (item) in
                    print(item)
                }, label: { Text("Temperature: \(Int(temperature))") })
           
       }.padding()
    }
}

View the result

25: Segment

A control for selecting from a set of options.
Code:

struct ContentView : View {
    
    private var animals = ["🐶 Dog", "🐯 Tiger", "🐷 Pig"]
    var colors = [Color.yellow, Color.orange, Color.red, Color.purple]
    @State private var selectedAnimal = 0

    var body: some View {
        VStack {
            Picker(selection: $selectedAnimal, label: Text("animals")) {
               ForEach(0 ..< animals.count) {
                Text(self.animals[\$0]).tag(\$0)
               }
            }.pickerStyle(SegmentedPickerStyle())
            Text("Your choice: \(animals[selectedAnimal])")
        }
    }
}

View the result

26: Toggle

A control that toggles between on and off states.
Code:

struct ContentView : View {
    @State var showNotification = true

    var body: some View {
        VStack {
            Text("Show Notification: ")
            + Text("\(self.showNotification.description)")
                .foregroundColor(.green)
                .bold()
                
            
            Toggle(isOn: $showNotification) {
                Text("Show notification:")
            }.padding()
        }
    }
}

View the result

27: TabView

A view that switches between multiple child views using interactive user interface elements.
Code:

var body: some View {
	TabView {
	    Text("The home page.")
		.font(.system(size: 36))
		.tabItem({
		    Image(systemName: "house")
		    Text("Home") })
		.tag(0)

	    Text("The settings page")
		.font(.system(size: 36))
		.tabItem({
		    Image(systemName: "gear")
		    Text("Settings")
		})
		.tag(1)
	}
    }

View the result

28: How to import WKWebview from UIKit

Code:

import SwiftUI
import WebKit

struct ContentView : UIViewRepresentable {
    
    func makeUIView(context: UIViewRepresentableContext<ContentView>) -> WKWebView {
        return WKWebView()
    }
    
    func updateUIView(_ uiView: WKWebView, context: UIViewRepresentableContext<ContentView>) {
        let request = URLRequest(url:URL(string: "https://apple.com")!)
        uiView.load(request)
    }
}

View the result

29: How to import MKMapView from UIKit

Code:

import SwiftUI
import MapKit

struct ContentView : UIViewRepresentable {
    
    func makeUIView(context: UIViewRepresentableContext<ContentView>) -> MKMapView {
        return MKMapView()
    }
    
    func updateUIView(_ uiView: MKMapView, context: UIViewRepresentableContext<ContentView>) {
        uiView.showsUserLocation = true
        uiView.mapType = MKMapType.satellite
        
        let coordinate2D = CLLocationCoordinate2D(latitude: 39.915352, longitude: 116.397105)
        let zoomLevel = 0.02
        let region = MKCoordinateRegion(center: coordinate2D, span: MKCoordinateSpan(latitudeDelta: zoomLevel, longitudeDelta: zoomLevel))
        uiView.setRegion(uiView.regionThatFits(region), animated: true)
    }
}

View the result

30: Shape-Circle

A circle centered on the frame of the view containing it.
Code:

VStack{
    Circle()
    Circle()
	.fill(Color.orange)
	.frame(width: 200, height: 200)
    ZStack {
       Circle().fill(Color.purple)
       Circle().fill(Color.yellow).scaleEffect(0.8)
       Circle().fill(Color.orange).scaleEffect(0.6)
    }
    Rectangle()
    Rectangle()
	.fill(Color.orange)
	.frame(width: 200, height: 200)
    ZStack {
       Rectangle().fill(Color.purple)
	.frame(width: 300, height: 200)

       Rectangle().fill(Color.yellow)
	.frame(width: 300, height: 200)
	.scaleEffect(0.8)

       Rectangle()
	.fill(Color.orange)
	.frame(width: 300, height: 200)
	.scaleEffect(0.6)
    }
}

View the result

31: Shape-Rectangle

A rectangular shape aligned inside the frame of the view containing it.
Code:

VStack{
            
    Rectangle()
    Rectangle()
	.fill(Color.orange)
	.frame(width: 200, height: 200)

    ZStack {
       Rectangle().fill(Color.purple)
	.frame(width: 300, height: 200)

       Rectangle().fill(Color.yellow)
	.frame(width: 300, height: 200)
	.scaleEffect(0.8)

       Rectangle()
	.fill(Color.orange)
	.frame(width: 300, height: 200)
	.scaleEffect(0.6)
    }

    RoundedRectangle(cornerRadius: 120)

    RoundedRectangle(cornerSize: CGSize(width: 100, height: 40)).frame(width: 300, height: 200)

    RoundedRectangle(cornerRadius: 100, style: RoundedCornerStyle.continuous)

}

View the result

32: 32Shape-Path

Code Shapes with Paths.
Code:

Path { path in
   path.move(to: CGPoint(x: 30, y: 0))
   path.addLine(to: CGPoint(x: 30, y: 200))
   path.addLine(to: CGPoint(x: 230, y: 200))
    path.addLine(to: CGPoint(x: 230, y: 0))
}

Path { path in
    path.addEllipse(in: CGRect(x: 100, y: 30, width: 200, height: 200))

    path.addRoundedRect(in: CGRect(x: 100, y: 120, width: 200, height: 200), cornerSize: CGSize(width: 10, height: 10))

    path.addEllipse(in: CGRect(x: 100, y: 210, width: 200, height: 200))
}

View the result

33: LinearGradien

The gradient applies the color function along an axis, as defined by its start and end points. The gradient maps the unit-space points into the bounding rectangle of each shape filled with the gradient.
Code:

Text("SwifUI Gradient")
    .font(.system(size: 36))
    .padding()
    .foregroundColor(.white)
    .background(LinearGradient(gradient: Gradient(colors: [.orange, .red, .purple]), startPoint: .topLeading, endPoint: .bottomTrailing))

}

View the result

34: AngularGradient

An angular gradient is also known as a “conic” gradient. This gradient applies the color function as the angle changes, relative to a center point and defined start and end angles.
Code:

VStack{
    Text("SwifUI Gradient")
    .font(.system(size: 36))
    .padding()
    .foregroundColor(.white)
    .background(AngularGradient(gradient: Gradient(colors: [.orange, .red, .purple]), center: UnitPoint(x: 0.5, y: 0.5), angle: Angle.init(degrees: -45)))

    Text("SwifUI Gradient")
    .font(.system(size: 36))
    .padding()
    .foregroundColor(.white)
    .background(AngularGradient(gradient: Gradient(colors: [.orange, .red, .purple]), center: UnitPoint(x: 0.5, y: 0.5), startAngle: Angle.init(degrees: 0), endAngle: Angle.init(degrees: 0)))

}

View the result

35: RadialGradient

The gradient applies the color function as the distance from a center point, scaled to fit within the defined start and end radii. The gradient maps the unit-space center point into the bounding rectangle of each shape filled with the gradient.
Code:

Text("SwifUI Gradient")
    .font(.system(size: 36))
    .padding()
    .foregroundColor(.white)
    .background(RadialGradient(gradient: Gradient(colors: [.orange, .red, .purple]), center: .init(x: 0.5, y: 0.5), startRadius: CGFloat(10), endRadius: CGFloat(120)))

}

View the result

#Chapter 2: Animation

1: scaleEffect+default

When using SwiftUI, you can individually animate changes to views, or to a view’s state, no matter where the effects are. SwiftUI handles all the complexity of these combined, overlapping, and interruptible animations for you.
Code:

struct ContentView : View {
    
    @State var factor: CGFloat = 1

    var body: some View {
        
        VStack{
            Image("logo")
                .scaleEffect(factor)
                .animation(.default)
            
            Divider().fixedSize()
            
            Button(action: {
                self.factor += 0.2
            }) {
                Text("Zoom in")
            }
        }
    }
}

View the result

2: Opacity+linear

Code:

struct ContentView : View {
    
    @State var factor: Double = 1
    @State var alpha: Double = 1

    var body: some View {
        Image("logo")
            .scaleEffect(CGFloat(factor))
            .opacity(alpha)
            .onTapGesture {
                withAnimation(.linear(duration: 1.0)) {
                    self.factor += 0.1
                    self.alpha -= 0.2
                }
            }
    }
}

View the result

3: Offset+easeOut

Code:

struct ContentView : View {
    
    @State var distance: Double = 0

    var body: some View {
        VStack{
            Image("logo")
                .offset(x: 0, y: CGFloat(distance))
                .animation(.easeOut(duration: 2))
            
            Divider().fixedSize()
            
            Button(action: {
                self.distance -= 120
            }) {
                Text("Move Effect")
            }
            
        }
        
    }
}

View the result

4: RotationEffect+spring

Code:

struct ContentView : View {
    
    @State var angle: Double = 0

    var body: some View {
        VStack{
            Image("logo")
            .rotationEffect(Angle.init(degrees: angle))
            .animation(.spring())
            
            Divider().fixedSize()
            
            Button(action: {
                self.angle += 90
            }) {
                Text("Rotation Effect")
            }
        }
    }
}

View the result

5: CombinedAnimation

Code:

struct ContentView : View {
    
    @State var radius: Double = 0
    @State var brightness: Double = 0

    var body: some View {
        VStack{
            Image("logo")
                .shadow(radius: CGFloat(radius))
                .brightness(brightness)
                .animation(.linear(duration: 2))
            
            Divider().fixedSize()
            
            Button(action: {
                self.radius += 10
                self.brightness = 1
            }) {
                Text("Move Effect")
            }
            
        }
        
    }
}

View the result

6: SpeadAndDelay

Code:

struct ContentView : View {
    @State var factor: Double = 1.0
    
    var animation: Animation {
        Animation.linear(duration: 1)
//            .speed(1)
//            .speed(5)
            .delay(2)
    }

    var body: some View {
        VStack{
            Image("logo")
            .scaleEffect(CGFloat(factor))
            .animation(animation)
            
            Divider().fixedSize()
            
            Button(action: {
                self.factor += 0.2
            }) {
                Text("Zoom In Effect")
            }
        }
    }
}

View the result

7: Repeating

Code:

struct ContentView : View {
    
    @State var angle: Double = 0
    
    var animation: Animation {
        Animation.spring()
             .repeatForever()
//            .repeatForever(autoreverses: false)
//            .repeatCount(3)
    }

    var body: some View {
        VStack{
            Image("logo")
                .rotationEffect(Angle.init(degrees: angle))
                .animation(animation)
            
            Divider().fixedSize()
            
            Button(action: {
                self.angle += 45
            }) {
                Text("Repeat Forever Effect")
            }
        }
    }
}

View the result

8: ToggleVisibility

Code:

struct ContentView : View {
    
    @State var showingPassword = false
    @State var password = ""

    var body: some View {
        
        VStack {
            Toggle(isOn: $showingPassword.animation(.spring())) {
                Text("Toggle Password")
            }

            if showingPassword {
                TextField("Password", text: $password)
                    .padding()
                    .border(Color.green, width: 1)
            }
        }
        .padding()
    }
}

View the result

9: AsymmetricTransition

Code:

struct ContentView : View {
    @State var showPicture = false

    var body: some View {
        VStack {
            Button(action: {
                withAnimation {
                    self.showPicture.toggle()
                }
            }) {
                Text("Show picture")
            }

            if showPicture {
//                Image("logo")
                
//                Image("logo")
//                    .transition(.move(edge: .top))
                
//                Image("logo")
//                    .transition(.scale(scale: 0))
                
//                Image("logo")
//                    .transition(.slide)
                
//                Image("logo")
//                    .transition(.asymmetric(insertion: .scale(scale: 0), removal: .slide))
                
                Image("logo")
                    .transition(AnyTransition.scale(scale: 0).combined(with:.slide))
            }
        }
    }
}

View the result

三章手势Gesture

1: TapGesture+Single tap

Code:

struct ContentView : View {
    
    @State var isPressed = false
    
    var body: some View {
        let tapGesture = TapGesture()
            .onEnded { _ in
                self.isPressed.toggle()
        }
        
        return Circle()
            .fill(Color.orange)
            .frame(width: 240, height: 240)
            .gesture(tapGesture)
            .scaleEffect(isPressed ? 1.4 : 1)
            .animation(.default)
    }
}

View the result

2: TapGesture+Double tap

Code:

struct ContentView : View {
    
    @State var isPressed = false
    
    var body: some View {
        
        return Circle()
            .fill(Color.orange)
            .frame(width: 240, height: 240)
            .scaleEffect(isPressed ? 1.4 : 1)
            .animation(.default)
            .onTapGesture(count: 2) {
                self.isPressed.toggle()
                print("Double tap.")
        }
    }
}

View the result

3: LongPressGesture

Code:

struct ContentView : View {
    
    @GestureState var isLongPressed = false
    
    var body: some View {
        let longPressGesture = LongPressGesture()
            .updating($isLongPressed) { value, state, transcation in
                print(value, state, transcation)
                state = value
            }
            .onEnded { (value) in
                print(value)
            }
        
        return Circle()
            .fill(Color.orange)
            .frame(width: 240, height: 240)
            .gesture(longPressGesture)
            .scaleEffect(isLongPressed ? 1.4 : 1)
            .animation(.default)
    }
}

View the result

4: RotationGesture

Code:

struct ContentView : View {
    
    @State var angle = 0.0
    
    var body: some View {
        let rotationGesture = RotationGesture(minimumAngleDelta: Angle.init(degrees: 20))
            .onChanged({ (angle) in
                
                self.angle += angle.animatableData
            }).onEnded { (angle) in
                print(self.angle)
        }
        
        return Image("logo")
            .gesture(rotationGesture)
            .rotationEffect(Angle.init(degrees: self.angle))
    }
}

View the result

5: DragGesture

Code:

struct ContentView : View {
    
    @State var offset: CGSize = .zero
    
    var body: some View {
        let dragGesture = DragGesture()
            .onChanged { (value) in
                print(value.startLocation, value.location, value.translation)
                self.offset = value.translation
            }
            .onEnded { (value) in
                if(abs(value.translation.width) >= 40 || abs(value.translation.height - (-260)) >= 40){
                    self.offset = .zero
                }
                else{
                    self.offset = CGSize(width: 0, height: -260)
                }
            }
        
        return VStack{
            Circle()
                .fill(Color.black)
                .opacity(0.1)
                .frame(width: 200, height: 200)
                .offset(CGSize(width: 0, height: -50))
            
            Circle()
                .fill(Color.orange)
                .frame(width: 200, height: 200)
                .offset(offset)
                .gesture(dragGesture)
                .animation(.spring())
        }
        
    }
}

View the result

6: LongPressGestureAndDragGesture

Code:

struct ContentView : View {
    
    @State var offset: CGSize = .zero
    @GestureState var isLongPressed = false
    
    var body: some View {
        let longPressGesture = LongPressGesture()
            .updating($isLongPressed) { value, state, transcation in
                print(value, state, transcation)
                state = value
        }
        .onEnded { (value) in
            print(value)
        }
        
        let dragGesture = DragGesture()
            .onChanged { (value) in
                print(value.startLocation, value.location, value.translation)
                self.offset = value.translation
        }
        .onEnded { (value) in
            if(abs(value.translation.width) >= 40 || abs(value.translation.height - (-260)) >= 40){
                self.offset = .zero
            }
            else{
                self.offset = CGSize(width: 0, height: -260)
            }
        }
        .simultaneously(with: longPressGesture)
        
        return VStack{
            Circle()
                .fill(Color.black)
                .opacity(0.1)
                .frame(width: 200, height: 200)
                .offset(CGSize(width: 0, height: -50))
            
            Circle()
                .fill(Color.orange)
                .frame(width: 200, height: 200)
                .offset(offset)
                .gesture(dragGesture)
                .scaleEffect(isLongPressed ? 1.4 : 1)
                .animation(.spring())
        }
        
    }
}

View the result

Chapter 4: Layout

1: Group

Code:

struct ContentView : View {
    
    var body: some View {
        Group {
            Text("Apple")
            Text("Banana")
            Text("Orange")
            Text("Watermelon")
            Text("Grape")
            Text("Papaya")
            Text("Pear")
        }
        .font(.title)
        .foregroundColor(.orange)
        .padding()
    }
}

View the result

2: HSTack

Code:

struct ContentView : View {
    
    var body: some View {
        HStack(alignment: .bottom, spacing: 40){
            Image(systemName: "book.fill")
            Text("Interactive Tutorials")
            Spacer()
            Image(systemName: "icloud.and.arrow.down")
        }
        .padding()
    }
}

View the result

3: VSTack

Code:

struct ContentView : View {
    
    var body: some View {
        VStack{
            Text("The fruit and the tree")
                .font(.largeTitle)
            Image("Apple")
            Text("An apple is a sweet, edible fruit produced by an apple tree Apple trees are cultivated worldwide and are the most widely grown species in the genus Malus.")
                .font(.body)
                .lineLimit(nil)
                .frame(height: 200)
        }.padding()
    }
}

View the result

4: ZSTack

Code:

struct ContentView : View {
    
    var body: some View {
        ZStack(alignment: .center){
            Image("beach").clipShape(Circle())
            Text("Sea beach")
                .font(.system(size: 48))
                .foregroundColor(.white)
            Text("Hawaii - USA")
                .font(.system(size: 14))
                .foregroundColor(.white)
                .offset(x: 0, y: 36)
        }.padding(10)
    }
}

View the result

5: List-Basic

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

            var body: some View {
                
                List{
                    Text("Objective-C")
                    Text("Swift")
                    Text("Flutter")
                }
                
//                List(0..<5) { item in
//                    Text("Item : \(item)")
//                }
                
//                ForEach(languages, id: \.self) { language in
//                    Text(language)
//                }
            }
}

View the result

6: List-Insert

Code:

struct ContentView : View {
    
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
        NavigationView {
            List {
                ForEach(languages, id:\.self) { language in
                    Text(language)
                }.onInsert(of: ["demo"], perform: { (offset, message) in
                    print(offset)
                })
            }
            .navigationBarTitle(Text("Edit Row"), displayMode: .large)
            .navigationBarItems(trailing: EditButton())
        }.padding()
    }

    func insertItem(to offsets: Int, message : [NSItemProvider]) {
        languages.insert(message[0].description, at: offsets)
    }
    
}

View the result

7: List-Delete

Code:

struct ContentView : View {

        @State var languages = ["Objective-C", "Swift", "Flutter"]

        var body: some View {
            NavigationView {
                List {
                    ForEach(languages,id: \.self) { language in
                        Text(language)
                    }
                    .onDelete(perform: delete)
                }
                .navigationBarItems(trailing: EditButton())
            }
        }

        func delete(at offsets: IndexSet) {
            if let first = offsets.first {
                languages.remove(at: first)
            }
        }
    }

View the result

8: List-Move

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
        NavigationView {
            List {
                ForEach(languages,id: \.self) { language in
                    Text(language)
                }
                .onMove { (source, destination) in
                    self.languages.move(fromOffsets: source, toOffset: destination)
                }
            }
            .navigationBarTitle(Text("Edit Row"), displayMode: .large)
            .navigationBarItems(trailing: EditButton())
        }
    }

    func moveItem(from source: IndexSet, to destination: Int) {
        languages.move(fromOffsets: source, toOffset: destination)
        print(languages)
    }
}

View the result

9: List-DeleteAndMove

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
        NavigationView {
            List {
                ForEach(languages, id: \.self) { language in
                    Text(language)
                }
                .onDelete(perform: deleteItem)
                .onMove(perform: moveItem)
            }
            .navigationBarTitle(Text("Edit Row"), displayMode: .large)
            .navigationBarItems(trailing: EditButton())
        }
    }

    func deleteItem(at offsets: IndexSet) {
        if let first = offsets.first {
            languages.remove(at: first)
        }
    }
    
    func moveItem(from source: IndexSet, to destination: Int) {
        languages.move(fromOffsets: source, toOffset: destination)
    }
}

View the result

10: ScrollView-Vertical

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
            ScrollView(.vertical, showsIndicators: false) {
                VStack(alignment: HorizontalAlignment.leading, spacing: 20){

                    Text("Overview")
                    .font(.system(size: 48))
                    .padding(10)
                    Text("With the power of Xcode, the ease of Swift, and the revolutionary features of cutting-edge Apple technologies, you have the freedom to create your most innovative apps ever.\nSwiftUI provides views, controls, and layout structures for declaring your app's user interface. The framework provides event handlers for delivering taps, gestures, and other types of input to your app, and tools to manage the flow of data from your app's models down to the views and controls that users will see and interact with.")
                    .lineLimit(nil)
                    .frame(width: 300, height: 240, alignment: .topLeading)
                    .padding(10)
                    
                    Image("iPhone")
                    .resizable()
                    .frame(width: 300, height: 556, alignment: .center)
                }
            }
            .background(Color.orange)
            .padding(10)
            .navigationBarTitle(Text("ScrollView"))
        }
    }

View the result

11: ScrollView-Horizontal

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
            ScrollView(.horizontal, showsIndicators: true) {
                HStack(alignment:.center, spacing: 20){

                    Image("iPhone")
                        .resizable()
                        .frame(width: 300, height: 556, alignment: .center)

                    Image("iPhoneSerial")
                        .resizable()
                        .frame(width: 823, height: 556, alignment: .center)

                    Image("iPhone")
                        .resizable()
                        .frame(width: 300, height: 556, alignment: .center)
                }
            }
            .background(Color.orange)
            .padding(10)
        }
    }

View the result

12: ScrollView-VerticalAndHorizontal

Code:

struct ContentView : View {
    @State var languages = ["Objective-C", "Swift", "Flutter"]

    var body: some View {
        ScrollView(.vertical, showsIndicators: false) {
            VStack(alignment: HorizontalAlignment.leading, spacing: 20){

                Text("Overview")
                .font(.system(size: 48))
                .padding(10)
                Text("With the power of Xcode, the ease of Swift, and the revolutionary features of cutting-edge Apple technologies, you have the freedom to create your most innovative apps ever.\nSwiftUI provides views, controls, and layout structures for declaring your app's user interface. The framework provides event handlers for delivering taps, gestures, and other types of input to your app, and tools to manage the flow of data from your app's models down to the views and controls that users will see and interact with.")
                .lineLimit(nil)
                .frame(width: 300, height: 350, alignment: .topLeading)
                .padding(10)
                
                ScrollView(.horizontal, showsIndicators: true) {
                    HStack(alignment:.center, spacing: 20){

                        Image("iPhone")
                            .resizable()
                            .frame(width: 189, height: 350, alignment: .center)

                        Image("iPhoneSerial")
                            .resizable()
                            .frame(width: 518, height: 350, alignment: .center)

                        Image("iPhone")
                            .resizable()
                            .frame(width: 189, height: 350, alignment: .center)
                    }
                }
                .background(Color.orange)
                .padding(10)
            }
        }
        .background(Color.orange)
        .padding(10)
        .navigationBarTitle(Text("ScrollView"))
    }
}

View the result

13: Form-Basic

Code:

struct ContentView : View {

    private var languages = ["Swift", "Objective-C"]
    @State private var selectedLanguage = 0
    @State var workingYear: Double = 2
    @State var enableNotification = false

    var body: some View {
        NavigationView {
            Form {
                Picker(selection: $selectedLanguage, label: Text("Languages")) {
                   ForEach(0 ..< languages.count) {
                    Text(self.languages[\$0]).tag(\$0)
                   }
                }.pickerStyle(SegmentedPickerStyle())
                HStack{
                    Text("Working years")
                    Slider(value: $workingYear, in: 1...10, step: 1)
                }
                
                Toggle(isOn: $enableNotification) {
                    Text("Enable Notification")
                }

                Button(action: {
                    print("Your programming language: \(self.languages[self.selectedLanguage])")
                    print("Your working years: \(Int(self.workingYear))")
                    print("Enable notification: \(self.enableNotification)")
                }) {
                    Text("Submit")
                }
            }.navigationBarTitle(Text("Profiles"))
        }
    }
}

View the result

14: Form-Segment

Code:

struct ContentView : View {
    private var languages = ["Swift", "Objective-C"]
    @State private var selectedLanguage = 0
    @State var workingYear: Double = 2
    @State var enableNotification = false
    var body: some View {
        NavigationView {
            Form {
                Section(header: Text("Please enter your information:"), footer: Text("Note: Enabling notification to get more infomration")) {
                    Picker(selection: $selectedLanguage, label: Text("Languages")) {
                       ForEach(0 ..< languages.count) {
                        Text(self.languages[\$0]).tag(\$0)
                       }
                    }.pickerStyle(SegmentedPickerStyle())
                    HStack{
                        Text("Working years")
                        Slider(value: $workingYear, in: 1...10, step: 1)
                    }
                    
                    Toggle(isOn: $enableNotification) {
                        Text("Enable Notification")
                    }
                }
                Button(action: {
                // activate theme!
                    print("Your programming language: \(self.languages[self.selectedLanguage])")
                    print("Your working years: \(Int(self.workingYear))")
                    print("Enable notification: \(self.enableNotification)")
                }) {
                    Text("Submit")
                }
            }.navigationBarTitle(Text("Profiles"))
        }
    }
}

View the result

15: Form-EnableDisable

Code:

struct ContentView : View {

    @State var enableForm = false
    @State var enableNotification = false
    @State var userName = ""
    @State var password = ""

    var body: some View {
        NavigationView {
            Form {
                Toggle(isOn: $enableForm) {
                    Text("Enable Form")
                }
                
                Section(header: Text("Please enter your information:")) {
                    
                    TextField("Username", text: $userName)
                    SecureField("Password", text: $password)
                    Toggle(isOn: $enableNotification) {
                        Text("Enable Notification")
                    }
                }.disabled(enableForm)
                
            }.navigationBarTitle(Text("Profiles"))
        }
    }
}

View the result

16: Form-ShowHide

Code:

struct ContentView : View {

    @State var showingVisible = false
    @State var userName = ""
    @State var password = ""

    var body: some View {
        NavigationView {
            Form {
                Toggle(isOn: $showingVisible.animation()) {
                    if(showingVisible){
                        Text("Hide Form")
                    }
                    else{
                        Text("Show Form")
                    }
                }
                
                if(showingVisible)
                {
                    Section(header: Text("Please enter your information:")) {
                        
                        TextField("Username", text: $userName)
                        SecureField("Password", text: $password)
                    }
                }
            }.navigationBarTitle(Text("Profiles"))
        }
    }
}

View the result

五章布局Layout

1: NavigationLink

Code:

struct ContentView : View {
    
    @State var isPresented = false
    var body: some View {
//            NavigationView {
//                HStack{
//                    NavigationLink(destination: Text("Detail Page #1") ) {
//                        Text("Go detail Page #1 >")
//                    }
//                    .navigationBarTitle("Index Page #1")
//                    .accentColor(Color.orange)
//                }
//            }
        
            NavigationView {
                HStack{
                    NavigationLink(destination: MyDetailView(message: "Detail Page #2") ) {
                        Text("Go detail Page #2 >")
                    }
                    .navigationBarTitle("Index Page #1")
                }
            }
            
    }
}

struct MyDetailView: View {
    
    let message: String

    var body: some View {
        VStack {
            Text(message)
                .font(.largeTitle)
        }
    }
}

View the result

2: NavigationLinkAndGoBack

Code:

struct ContentView : View {
    
    @State private var isPresented = false
    
    var body: some View {
        
//            NavigationView{
//                VStack{
//                Image("Picture").onTapGesture {
//                    self.isPresented.toggle()
//                    print(self.isPresented)
//                }
//                NavigationLink(destination: Text("< Go back").onTapGesture {
//                    self.isPresented.toggle()
//                }, isActive: $isPresented) {
//                    Text("ddd")
//                }
//            }
        
        NavigationView{
            VStack{
                NavigationLink(destination: DetailView(preView: self), isActive: $isPresented) {
                    Image("logo").renderingMode(.original)
                    Text("Next Page >")
                }
            }
        }
    }
    
    func toggleValue()
    {
        self.isPresented.toggle()
    }
}

View the result

3: PageNavigation

Code:

import SwiftUI

struct InfoModel : Hashable {
    var description : String
    var pictureName : String
}
struct ContentView : View {
    
    var messages : [InfoModel]
    
    var body: some View {
        return NavigationView{
            List{
                ForEach(messages, id: \.self) { message in
                    NavigationLink(destination: DetailView(imageName: message.pictureName)) {
                        Text(message.description)
                    }
                }
            }.navigationBarTitle("Picture List")
        }
    }
}
struct DetailView : View {
    var imageName : String
    var body: some View{
        Image(imageName)
    }
}
#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        let model1 = InfoModel(description: "A lady with a horse", pictureName: "Picture1")
        let model2 = InfoModel(description: "An African animal with a very long neck", pictureName: "Picture2")
        return ContentView(messages: [model1, model2])
    }
}
#endif

View the result

4: ObjectBinding

Code:

class UserModel: ObservableObject {
    @Published var nickName: String = ""
}

struct ContentView : View {
    @ObservedObject var model = UserModel()
    @State var isPresented = false

    let dismiss = Alert.Button.default(Text("OK")) {}
    var alert: Alert {
        Alert(title: Text("Your nickname"),
             message: Text("\(self.model.nickName)"),
             dismissButton: dismiss)
    }
    
    var body: some View {
        VStack {
            TextField("Your nickname", text: $model.nickName)
            .padding()
            
            Button(action: {
                self.isPresented = true
            }) {
                Text("Show")
            }.alert(isPresented: $isPresented) { () -> Alert in
                alert
            }
        }
    }
}

View the result

5: EnviromentObject

Code:

import SwiftUI

class UserModel: ObservableObject {
    @Published var nickName: String = ""
}

struct ContentView : View {
    
    @EnvironmentObject var model : UserModel
    @State var isPresented = false
    
    var body: some View {
        NavigationView {

            VStack{
                TextField("Your nickname", text: $model.nickName)
                .padding()
                
                NavigationLink(destination: DetailView()) {
                    Text("Show Detail")
                }
            }
        }
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        let model = UserModel()
        model.nickName = "Super man"
        return ContentView().environmentObject(model)
    }
}
#endif

View the result

6: Show_Modal

Code:

struct ContentView : View {
    
    @State var isPresented = false

    var modalView: some View {
        Text("The Modal View")
            .font(.system(size: 48))
            .bold()
    }

    var body: some View {
        Button("Show Modal View") {
            self.isPresented = true
        }.sheet(isPresented: $isPresented, content: {
            self.modalView
        })
    }
}

View the result

7: Show-Alert

Code:

struct ContentView : View {
    
        @State var isAlert = false

        let primaryButton = Alert.Button.default(Text("Yes")) {
            print("Yes, I'm a student.")
        }
    
        let secondaryButton = Alert.Button.destructive(Text("No")) {
            print("No, I'm not a student.")
        }
        
        var alert: Alert {
            Alert(title: Text("Question"),
                  message: Text("Are you a student?"),
                  primaryButton: primaryButton,
                  secondaryButton: secondaryButton)
        }

        var body: some View {
            VStack {
                Button("Alert Sheet") {
                    self.isAlert = true
                }
            }.alert(isPresented: $isAlert, content: {
                alert
            })

        }
    }

View the result

8: Show-ActionSheet

Code:

struct ContentView : View {
    
    @State var isPresented = false

    var myActionSheet: ActionSheet {
        ActionSheet(title: Text("Information"),
            message: Text("What's your favorite?"),
            buttons: [
                .default(Text("Fishing")) {
                    print("---I like fishing")
                },
                .destructive(Text("Hunting")) {
                    print("---I like hunting")
                },
                .cancel({
                    print("---Nothing")
                })
            ]
        )
    }

    var body: some View {
        VStack {
            Button("Show action sheet") {
                self.isPresented = true
            }
        }
        .actionSheet(isPresented: $isPresented, content: {
            myActionSheet
        })
    }
}

View the result

六章更多...

1: PreviewInNavigationView

Code:

struct ContentView : View {
    var body: some View {
        VStack{
            Image("SwiftUI")
            .navigationBarTitle("About SwiftUI")
            Text("SwiftUI is an innovative, exceptionally simple way to build user interfaces across all Apple platforms with the power of Swift. Build user interfaces for any Apple device using just one set of tools and APIs. With a declarative Swift syntax that’s easy to read and natural to write, SwiftUI works seamlessly with new Xcode design tools to keep your code and design perfectly in sync. Automatic support for Dynamic Type, Dark Mode, localization, and accessibility means your first line of SwiftUI code is already the most powerful UI code you’ve ever written.")
            .padding()
        }
    }
}

View the result

2: Background

Code:

struct ContentView : View {
    
    var body: some View {
        
        VStack{
            
            Spacer()
            
            Text("SwiftUI Tutorials")
                .font(.largeTitle)
                .padding()
                .background(Color.orange)
            
            Spacer()
            
            Text("SwiftUI Tutorials")
            .font(.largeTitle)
            .padding()
            .background(Image("iPhoneSerial")
                .resizable())
            
            Spacer()
            
            Text("SwiftUI Tutorials")
                .font(.largeTitle)
                .padding()
                .background(Circle()
                    .fill(Color.orange)
                    .frame(width: 280, height: 280))
            
            Spacer()
            
        }

    }
}

View the result

3: SizeCategory

Code:

struct ContentView : View {
    var body: some View {
        VStack{
            Text("Dynamic Type sizes")
                .font(.system(size: 36))
            Text("Dynamic Type sizes")
        }
        
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        VStack{
            
            Spacer()
            ContentView()
                .environment(\.sizeCategory, .extraSmall)
            Spacer()
            ContentView()
            Spacer()

            ContentView()
               .environment(\.sizeCategory, .accessibilityExtraExtraExtraLarge)
            
            Spacer()
        }
        
    }
}
#endif

View the result

4: PreviewDevice

Code:

struct ContentView : View {
    var body: some View {
        VStack{
            Text("Dynamic Type sizes")
                .font(.system(size: 48))
            Text("Dynamic Type sizes")
        }
        
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        Group {
           ContentView()
              .previewDevice(PreviewDevice(rawValue: "iPhone 8"))
              .previewDisplayName("Device-8")

           ContentView()
              .previewDevice(PreviewDevice(rawValue: "iPhone XS Max"))
              .previewDisplayName("Device-XS Max")
        }
    }
}
#endif

View the result

5: ViewAsProperties

Code:

struct ContentView : View {
    
    let icon = Image(systemName: "book.fill")
    let title = Text("Interactive Tutorials")
    let flag = Image(systemName: "icloud.and.arrow.down")
    
    var body: some View {
        HStack(alignment: .bottom, spacing: 40){
            icon
            title
            Spacer()
            flag
        }
        .padding()
    }
}

View the result

6: onAppear-onDisappear

Code:

struct DetailView: View {
    var body: some View {
        Text("Detail")
        .onAppear {
            print("DetailView appeared!")
        }.onDisappear {
            print("DetailView disappeared!")
        }
    }
}

struct ContentView : View {
    
    @State private var isPresented = false
    
    var body: some View
    {
        Text("Show Detail > ").sheet(isPresented: $isPresented, content: {
            DetailView()
        }).onTapGesture {
            self.isPresented = true
        }.onDisappear {
            print("ContentView disappeared!")
        }.onAppear {
            print("ContentView appeared!")
        }
    }
}

View the result

7: ColorScheme-LightAndDark

Code:

struct ContentView : View {
    var body: some View {
        VStack(alignment: .center, spacing: 20){
            Text("Dynamic Type sizes")
                .font(.system(size: 48))
                .foregroundColor(Color.secondary)
            Text("Dynamic Type sizes")
                .foregroundColor(Color.accentColor)
            Image(systemName: "star.fill")
                .foregroundColor(Color.secondary)
                .font(.system(size: 64))
        }
        .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
        .background(Color.primary)
        .edgesIgnoringSafeArea(.all)
        
    }
}

#if DEBUG
struct ContentView_Previews : PreviewProvider {
    static var previews: some View {
        HStack {
           ContentView()
              .environment(\.colorScheme, .light)

           ContentView()
              .environment(\.colorScheme, .dark)
        }
        
    }
}
#endif

View the result

8: AnyView

Code:

struct ContentView : View {
    
    private var randomBool = Bool.random()
    
//    var body: some View {
//        Group {
//            if randomBool {
//                Text("Hi, you get the gift.")
//                    .font(.system(size: 32))
//            } else {
//                Text("Sorry, you miss the gift.")
//                    .font(.system(size: 32))
//            }
//        }
//    }
    
//    var body: some View {
//        if randomBool {
//            return Text("Hi, you get the gift.")
//                .font(.system(size: 32))
//        } else {
//            return Text("Sorry, you miss the gift.")
//                .font(.system(size: 32))
//        }
//    }
    
    var body: AnyView {
        if randomBool {
            return AnyView(Image(systemName: "star.fill").font(.system(size: 72)))
        } else {
            return AnyView(Text("Sorry, you miss the gift.").font(.system(size: 32)))
        }
    }
}

View the result

9: NavigationBarTitle

Code:

struct ContentView : View {

    var body: some View {
        NavigationView {
            
//            Text("SwiftUI's NavigationView")
            
//            Text("SwiftUI's NavigationView")
//                .navigationBarTitle(Text("SwiftUI"))
            
//            Text("SwiftUI's NavigationView")
//                .navigationBarTitle(Text("SwiftUI"), displayMode: .large)
            
            Text("SwiftUI's NavigationView")
                .navigationBarTitle(Text("SwiftUI"), displayMode: .inline)
        }
    }
}

View the result

10: NavigationItem

Code:

struct TrailingButtons : View{
    var body: some View {
        HStack{
            Button(action: {
                print("Download the data")
            }) {
                Image(systemName: "icloud.and.arrow.down.fill")
            }
            Button(action: {
                print("Edit the data")
            }) {
                Image(systemName: "pencil.tip.crop.circle")
            }
        }
    }
}

struct ContentView : View {

    var body: some View {
        NavigationView {
            Text("SwiftUI's NavigationView")
                .navigationBarTitle(Text("SwiftUI"))
                .navigationBarItems(leading:  Button(action: {
                       print("Go to index page")
                   }) {
                       Text("Index")
                   }, trailing: TrailingButtons())
        }
    }
}

View the result

11: ViewModifier

Code:

struct ContentView : View {
    
    var body: some View {
        VStack(alignment: .center, spacing: 40){
            Image("avarta1").modifier(myImageStyle())
            Image("avarta2").modifier(myImageStyle())
            Image("avarta3").modifier(myImageStyle())
        }
        .padding()
    }
}

struct myImageStyle: ViewModifier {
    func body(content: Content) -> some View {
        content
            .frame(width: 200, height: 200, alignment: .leading)
            .cornerRadius(100)
            .clipped()
            .saturation(0.0)
    }
}

View the result

SwiftUI

Navigator：

Chapter 1: Views

1、How to create a SwiftUI project:

2: Text-BasicStyle

3: Text-Paragraph

4: Text-Padding

5: Text-FullScreen

6: Text-DateFormatter

7: Text-Append

8: TextField

9: TextField-SecureField

10: Button

11: Button-sheet

12: Spacer

13: Divider

14: Image-Basic

15: Image-Style

16: Image-Processing

17: Image-Blend

18: Image-Mask

19: Image-Transform

20: Image-Web

21: Picker

22: DatePicker

23: Slider

24: Stepper

25: Segment

26: Toggle

27: TabView

28: How to import WKWebview from UIKit

29: How to import MKMapView from UIKit

30: Shape-Circle

31: Shape-Rectangle

32: 32Shape-Path

33: LinearGradien

34: AngularGradient

35: RadialGradient

1: scaleEffect+default

2: Opacity+linear

3: Offset+easeOut

4: RotationEffect+spring

5: CombinedAnimation

6: SpeadAndDelay

7: Repeating

8: ToggleVisibility

9: AsymmetricTransition

三章 手势Gesture

1: TapGesture+Single tap

2: TapGesture+Double tap

3: LongPressGesture

4: RotationGesture

5: DragGesture

6: LongPressGestureAndDragGesture

Chapter 4: Layout

1: Group

2: HSTack

3: VSTack

4: ZSTack

5: List-Basic

6: List-Insert

7: List-Delete

8: List-Move

9: List-DeleteAndMove

10: ScrollView-Vertical

11: ScrollView-Horizontal

12: ScrollView-VerticalAndHorizontal

13: Form-Basic

14: Form-Segment

15: Form-EnableDisable

16: Form-ShowHide

五章 布局Layout

1: NavigationLink

2: NavigationLinkAndGoBack

3: PageNavigation

4: ObjectBinding

5: EnviromentObject

6: Show_Modal

7: Show-Alert

8: Show-ActionSheet

三章手势Gesture

五章布局Layout

六章更多...