SwiftUI 布局框架

基本观点

Text

用于显示一行或多行文本内容，效果与相同UILabel，但效果更好。

如果要创建Text，只需使用创建它Text("SwiftUI")；使用链接的语法，您还可以向文本添加多个属性，例如字体，颜色，阴影，左上和右上的间距等等。

例：

Text("SwiftUI")
    .foregroundColor(.orange)
    .bold()
    .font(.system(.largeTitle))
    .fontWeight(.medium)
    .italic()
    .shadow(color: .black, radius: 1, x: 0, y: 2)

查看运行结果

HStack and VStack controls are used to host multiple views, as mentioned later.

文本域

TextField 用于添加普通输入框，通常将其用作文本输入。

Example：

TextField(self.$name, placeholder: self.nameText, onEditingChanged: { changed in
    print("onEditing: \(changed)")
}) {
    print("userName: \(self.name)")
    self.endEditing(true)
}}
.padding(10)
.frame(height: 50)
.textFieldStyle(RoundedBorderTextFieldStyle())
.padding(EdgeInsets(top: 0, leading: 20, bottom: 0, trailing: 20))

 

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SecureField

SecureField is generally used as a password input. It is used in the same way as TextField. The example and the running effect are the same as TextField.

Image

The Image control is used to display images, example:

Image("icon")
    .resizable()
    .frame(width: 100,
           height: 100,
           alignment: .center)

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WebImage

webImage is used to download the web image, use the URLSession to download the original Image after successful download; you can also use Kingfisher in the downloadWebImage function .

Example：

var body: some View {
        Image(uiImage: self.uiImage ?? placeholderImage)
            .resizable()
            .onAppear(perform: downloadWebImage)
            .frame(width: 80,
                   height: 80,
                   alignment: .center)
            .onTapGesture {
                print("Tap ")
        }
    }

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Button

Button is used to respond to click events.

Example:

Button(action: {
    print("Tap")
}) {
   Text("I'm a Button")
}

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PullDownButton

Waiting for release.

ItemBasedPopUpButton

Waiting for release.

NavigationButton

NavigationButtonPage is used to push to the next navigation page.

Example:

NavigationLink(destination: NavigationButtonPage()) {
            Text("NavigationButton").bold()
                .foregroundColor(.orange)
                .font(.largeTitle)
            }
    .navigationBarTitle(Text("Page"))

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PresentationButton is deprecated

PresentationButton is used to pop up a page. has deprecated, please use NavigationLink

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EditButton

EditButton is used to trigger the editing state, just use the navigationBarItems setting when using it.

Example:

navigationBarItems(trailing: EditButton())

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PasteButton

Waiting for release.

Picker

Picker can customize the selector of the data source.

Example:

Picker(selection: $leftIndex, label: Text("Picker")) {
    ForEach(0..<leftSource.count) {
        Text(self.leftSource[$0]).tag($0)
    }
    }.frame(width: UIScreen.main.bounds.width/2)

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DatePicker

DatePicker is used to select the absolute date of the control.

Example:

                DatePicker(selection: $server.date, 
                in: server.spaceDate, 
                displayedComponents: .date, label: {
                    Text("")
                })

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Toggle

Toggle is used to switch the selected state, for example:

Togglele(isOn: $isOn) {
    Text("State: \(self.isOn == true ? "Open":"open")")
}.padding(20)

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Slider

Slider A control for selecting values from a finite range of values, example:

Slider(value: $data.rating)

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Stepper

Stepper is used to increase or decrease the value, example:

Stepper(value: $value, step: 2, onEditingChanged: { c in
    print(c)
}) {
    Text("Stepper Value: \(self.value)")
    }.padding(50)

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SegmentedControl is deprecated

SegmentedControl is used for segmentation condition selection, example:

SegmentedControl(selection: $currentIndex) {
    ForEach(0..<items.count) { index in
        Text(self.items[index]).tag(index)
    }
    }.tapAction {
        print("currentIndex: \(self.currentIndex)")
}

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WebView

WebView is used to display an open web page, example:

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

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UIViewController

UIViewController is used to display the UIViewController that opens UIKit in SwiftUI and opens the SwiftUI View in UIViewController.

Example:

First define:

struct ControllerPage<T: UIViewController> : UIViewControllerRepresentable {
    
    typealias UIViewControllerType = UIViewController
    
    func makeUIViewController(context: UIViewControllerRepresentableContext<ControllerPage>) -> UIViewController {
        return T()
    }
    
    func updateUIViewController(_ uiViewController: UIViewController, context: UIViewControllerRepresentableContext<ControllerPage>) {
        debugPrint("\(#function)：\(type(of: T.self))")
    }
    
}

Then use this:

NavigationButton(destination: ControllerPage<UIKitController>()) {
    PageRow(title: "UIViewController",subTitle: "Open UIViewController")

}

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Layout

HStack

HStack is used to arrange the subviews on a horizontal line.

Example:

HStack {
    Text("made in China.")
    Divider() // Just add a line.
    Text("the People's Republic Of China.")
}

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VStack

VStack is used to arrange the subviews on a vertical line.

Example:

VStack {
    Text("made in China.")
    Divider() // Just add a line.
    Text("the People's Republic Of China.")
}

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ZStack

ZStack is used to override the subview, aligned on two axes.

Example:

ZStack {
    Text("made in China.")
    Divider() // Just add a line.
    Text("the People's Republic Of China.")
}

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List

List list container to display a list of data.

Examples:

List(0..<5) { item in
    Text("Hello World !")
}.navigationBarTitle(Text("List"), displayMode: .large)

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ScrollView

ScrollView is a scroll view container.

Example:

ScrollView {
    Text("SwiftUI").padding(20)
    Divider()
    Image("icon").resizable()
        .frame(width: 300, height: 300, alignment: .center)
    Divider()
    Text("Views and ... user interface.")
    }
    .border(Color.gray.gradient, width: 1)
            .cornerRadius(10)
            .padding(10)
            .navigationBarTitle(Text("ScrollView"))

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ForEach

ForEach is used to present a view based on a collection of existing data.

Example:

let data = (0..<5)
var body: some View {
    ForEach(data) { e in
        Text("Hello \(e)")
            .bold()
            .font(.system(size: 25, design: .monospaced))
            .padding(5)
}

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Group

Group is used to aggregate multiple views, and the properties set on the Group will be applied to each child view.

Example:

Group {
    Text("Hello World !")
    Text("Hello World !")
    }

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GroupBox

Waiting for release.

Section

Section is used to create the header/footer view content, which is generally used in conjunction with the List component.

Example:

Section(header: Text("I'm header"), footer: Text("I'm footer")) {
    ForEach(0..<3) {
        Text("Hello \($0)")
    }
}

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Form

Form A container for grouping controls used for data entry, such as in settings or inspectors.

Example:

Form {
   TextField("First Name", text: $firstName)
   TextField("Last Name", text: $lastName)
}

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NavigationView

NavigationView is used to create a view container that contains the top navigation bar.

Example:

NavigationView {
            Text("🧚‍♂️🧚‍♀️🧜‍♂️🧜‍♀️🧞‍♂️🧞‍♀️").blur(radius: 5)
            Text("Swifter Swifter")
            .bold()
                .foregroundColor(.orange)
                .font(.largeTitle)
        }
    .navigationBarTitle(Text("NavigationView"))

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TabView

TabView is used to create a view container that contains the bottom ** TabBar**.

Example:

TabView(selection: $index) {
    ForEach(0..<imgs.count) { item in
        TabItemPage(index: item)
            .tabItem{
                Image(self.imgs[item])
                Text("\(item)")
        }
        .tag(item)
    }
}

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HSplitView

Waiting for release.

VSplitView

Waiting for release.

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Alert

Alert is used to display a bullet reminder that needs to be associated with a trigger event.

Example:

alert(isPresented: $showAlert, content: {
            Alert(title: Text("确定要支付这100000000美元吗？"),
                  message: Text("请谨慎操作\n一旦确认，钱款将立即转入对方账户"),
                  primaryButton: .destructive(Text("确认")) { print("转出中...") },
                  secondaryButton: .cancel())
        }).navigationBarTitle(Text("Alert"))

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ActionSheet

ActionSheet is used to pop up a selection box.

Example:

ActionSheet(title: Text("Title"),
            message: Text("Message"),
            buttons:
    [.default(Text("Default"), onTrigger: {
        print("Default")
        self.showSheet = false
    }),.destructive(Text("destructive"), onTrigger: {
        print("destructive")
        self.showSheet = false
    }),.cancel({
        print("Cancel")
        self.showSheet = false
    })])

usage：

.actionSheet(isPresented: $showSheet, content: {sheet})

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Modal

Modal is used to pop up a view.

Example:

Modal(Text("Modal View"),onDismiss: {
    print("View Dismiss !")
})

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Popover

Popover is used to pop up a view, see the results below.

Example:

.popover(isPresented: $showPop, content: {
                ImagePage()
            })

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