SwiftUI - 半模态？

Question

我正在尝试在 SwiftUI 中重新创建类似于 iOS13 中的 Safari 的 Modal：

它是这样的：

有谁知道这在 SwiftUI 中是否可行？我想显示一个小的半模态，可以选择拖动到全屏，就像共享表一样。

非常感谢任何建议！

Answer 1

从 Beta 2 Beta 3 开始，您不能将模态 View 显示为 .fullScreen。它显示为.automatic -> .pageSheet。但是，即使解决了这个问题，我也非常怀疑他们是否会免费为您提供拖动功能。它已经包含在文档中了。

您现在可以使用this answer 全屏显示。 Gist here.

然后，在演示之后，这是一个快速而肮脏的示例，说明如何重新创建该交互。

    @State var drag: CGFloat = 0.0

    var body: some View {
        ZStack(alignment: .bottom) {
            Spacer() // Use the full space
            Color.red
                .frame(maxHeight: 300 + self.drag) // Whatever minimum height you want, plus the drag offset
                .gesture(
                    DragGesture(coordinateSpace: .global) // if you use .local the frame will jump around
                        .onChanged({ (value) in
                            self.drag = max(0, -value.translation.height)
                        })
                )
        }
    }

Answer 2

您可以自己制作并将其放在 zstack 中： https://www.mozzafiller.com/posts/swiftui-slide-over-card-like-maps-stocks

struct SlideOverCard<Content: View> : View {
    @GestureState private var dragState = DragState.inactive
    @State var position = CardPosition.top

    var content: () -> Content
    var body: some View {
        let drag = DragGesture()
            .updating($dragState) { drag, state, transaction in
                state = .dragging(translation: drag.translation)
            }
            .onEnded(onDragEnded)

        return Group {
            Handle()
            self.content()
        }
        .frame(height: UIScreen.main.bounds.height)
        .background(Color.white)
        .cornerRadius(10.0)
        .shadow(color: Color(.sRGBLinear, white: 0, opacity: 0.13), radius: 10.0)
        .offset(y: self.position.rawValue + self.dragState.translation.height)
        .animation(self.dragState.isDragging ? nil : .spring(stiffness: 300.0, damping: 30.0, initialVelocity: 10.0))
        .gesture(drag)
    }

    private func onDragEnded(drag: DragGesture.Value) {
        let verticalDirection = drag.predictedEndLocation.y - drag.location.y
        let cardTopEdgeLocation = self.position.rawValue + drag.translation.height
        let positionAbove: CardPosition
        let positionBelow: CardPosition
        let closestPosition: CardPosition

        if cardTopEdgeLocation <= CardPosition.middle.rawValue {
            positionAbove = .top
            positionBelow = .middle
        } else {
            positionAbove = .middle
            positionBelow = .bottom
        }

        if (cardTopEdgeLocation - positionAbove.rawValue) < (positionBelow.rawValue - cardTopEdgeLocation) {
            closestPosition = positionAbove
        } else {
            closestPosition = positionBelow
        }

        if verticalDirection > 0 {
            self.position = positionBelow
        } else if verticalDirection < 0 {
            self.position = positionAbove
        } else {
            self.position = closestPosition
        }
    }
}

enum CardPosition: CGFloat {
    case top = 100
    case middle = 500
    case bottom = 850
}

enum DragState {
    case inactive
    case dragging(translation: CGSize)

    var translation: CGSize {
        switch self {
        case .inactive:
            return .zero
        case .dragging(let translation):
            return translation
        }
    }

    var isDragging: Bool {
        switch self {
        case .inactive:
            return false
        case .dragging:
            return true
        }
    }
}

Answer 3

我编写了一个 Swift 包，其中包含一个自定义修饰符，允许您使用半模态表。

这里是链接：https://github.com/AndreaMiotto/PartialSheet

随意使用或贡献

Answer 4

这是我幼稚的底部表格，可缩放到其内容。无需拖动，但如果需要添加应该相对容易:)

struct BottomSheet<SheetContent: View>: ViewModifier {
@Binding var isPresented: Bool
let sheetContent: () -> SheetContent

func body(content: Content) -> some View {
    ZStack {
        content

        if isPresented {
            VStack {
                Spacer()

                VStack {
                    HStack {
                        Spacer()
                        Button(action: {
                            withAnimation(.easeInOut) {
                                self.isPresented = false
                            }
                        }) {
                            Text("done")
                                .padding(.top, 5)
                        }
                    }

                    sheetContent()
                }
                .padding()
            }
            .zIndex(.infinity)
            .transition(.move(edge: .bottom))
            .edgesIgnoringSafeArea(.bottom)
        }
    }
}

extension View {
    func customBottomSheet<SheetContent: View>(
        isPresented: Binding<Bool>,
        sheetContent: @escaping () -> SheetContent
    ) -> some View {
        self.modifier(BottomSheet(isPresented: isPresented, sheetContent: sheetContent))
    }
}

并像下面这样使用：

.customBottomSheet(isPresented: $isPickerPresented) {
                DatePicker(
                    "time",
                    selection: self.$time,
                    displayedComponents: .hourAndMinute
                )
                .labelsHidden()
        }

Answer 5

Andre Carrera 的回答很棒，您可以随意使用他提供的本指南：https://www.mozzafiller.com/posts/swiftui-slide-over-card-like-maps-stocks

我已经修改了 SlideOverCard 结构，因此它使用实际设备高度来测量卡片应该停止的位置（您可以使用 bounds.height 来调整以适应您的需要）：

struct SlideOverCard<Content: View>: View {

    var bounds = UIScreen.main.bounds
    @GestureState private var dragState = DragState.inactive
    @State var position = UIScreen.main.bounds.height/2

    var content: () -> Content
    var body: some View {
        let drag = DragGesture()
            .updating($dragState) { drag, state, transaction in
                state = .dragging(translation: drag.translation)
            }
            .onEnded(onDragEnded)

        return Group {
            Handle()
            self.content()
        }
        .frame(height: UIScreen.main.bounds.height)
        .background(Color.white)
        .cornerRadius(10.0)
        .shadow(color: Color(.sRGBLinear, white: 0, opacity: 0.13), radius: 10.0)
        .offset(y: self.position + self.dragState.translation.height)
        .animation(self.dragState.isDragging ? nil : .interpolatingSpring(stiffness: 300.0, damping: 30.0, initialVelocity: 10.0))
        .gesture(drag)
    }

    private func onDragEnded(drag: DragGesture.Value) {
        let verticalDirection = drag.predictedEndLocation.y - drag.location.y
        let cardTopEdgeLocation = self.position + drag.translation.height
        let positionAbove: CGFloat
        let positionBelow: CGFloat
        let closestPosition: CGFloat

        if cardTopEdgeLocation <= bounds.height/2 {
            positionAbove = bounds.height/7
            positionBelow = bounds.height/2
        } else {
            positionAbove = bounds.height/2
            positionBelow = bounds.height - (bounds.height/9)
        }

        if (cardTopEdgeLocation - positionAbove) < (positionBelow - cardTopEdgeLocation) {
            closestPosition = positionAbove
        } else {
            closestPosition = positionBelow
        }

        if verticalDirection > 0 {
            self.position = positionBelow
        } else if verticalDirection < 0 {
            self.position = positionAbove
        } else {
            self.position = closestPosition
        }
    }
}

enum DragState {
    case inactive
    case dragging(translation: CGSize)

    var translation: CGSize {
        switch self {
        case .inactive:
            return .zero
        case .dragging(let translation):
            return translation
        }
    }

    var isDragging: Bool {
        switch self {
        case .inactive:
            return false
        case .dragging:
            return true
        }
    }
}

Answer 6

我编写了一个 SwiftUI 包，其中包括自定义 iOS 13，如半模态及其按钮。

GitHub 仓库：https://github.com/ViktorMaric/HalfModal

Answer 7

我认为几乎每个在 SwiftUI 中编写任何东西的 iOS 开发人员都必须反对这一点。我当然做到了，但我认为这里的大多数答案要么太复杂，要么并没有真正提供我想要的。

我在 GitHub 上写了一个非常简单的部分工作表，可作为 Swift 包提供 - HalfASheet

它可能没有其他一些解决方案的花里胡哨，但它做了它需要做的事情。此外，编写自己的代码总是有助于了解正在发生的事情。

注意 - 有几件事 - 首先，这是一个正在进行中的工作，请随时改进，等等。其次，我故意不做一个 .podspec，就好像你是为 SwiftUI 开发，你至少在 iOS 13 上，我认为 Swift 包要好得多......

Answer 8

我试图做同样的事情，在 SwiftUI 中以本机方式显示共享表，而不必实现/导入组件。 我在https://jeevatamil.medium.com/how-to-create-share-sheet-uiactivityviewcontroller-in-swiftui-cef64b26f073找到了这个解决方案

struct ShareSheetView: View {
    var body: some View {
        Button(action: actionSheet) {
            Image(systemName: "square.and.arrow.up")
                .resizable()
                .aspectRatio(contentMode: .fit)
                .frame(width: 36, height: 36)
        }
    }
    
    func actionSheet() {
        guard let data = URL(string: "https://www.zoho.com") else { return }
        let av = UIActivityViewController(activityItems: [data], applicationActivities: nil)
        UIApplication.shared.windows.first?.rootViewController?.present(av, animated: true, completion: nil)
    }
}

Answer 9

在 Swift 5.5 iOS 15+ 和 Mac Catalyst 15+ 中有一个

adaptiveSheetPresentationController 有一个新的解决方案

https://developer.apple.com/documentation/uikit/uipopoverpresentationcontroller/3810055-adaptivesheetpresentationcontrol?changes=__4

@available(iOS 15.0, *)
struct CustomSheetParentView: View {
    @State private var isPresented = false
    
    var body: some View {
        VStack{
            Button("present sheet", action: {
                isPresented.toggle()
            }).adaptiveSheet(isPresented: $isPresented, detents: [.medium()], smallestUndimmedDetentIdentifier: .large){
                Rectangle()
                    .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .center)
                    .foregroundColor(.clear)
                    .border(Color.blue, width: 3)
                    .overlay(Text("Hello, World!").frame(maxWidth: .infinity, maxHeight: .infinity)
                                .onTapGesture {
                        isPresented.toggle()
                    }
                    )
            }
            
        }
    }
}
@available(iOS 15.0, *)
struct AdaptiveSheet<T: View>: ViewModifier {
    let sheetContent: T
    @Binding var isPresented: Bool
    let detents : [UISheetPresentationController.Detent]
    let smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier?
    let prefersScrollingExpandsWhenScrolledToEdge: Bool
    let prefersEdgeAttachedInCompactHeight: Bool
    
    init(isPresented: Binding<Bool>, detents : [UISheetPresentationController.Detent] = [.medium(), .large()], smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier? = .medium, prefersScrollingExpandsWhenScrolledToEdge: Bool = false, prefersEdgeAttachedInCompactHeight: Bool = true, @ViewBuilder content: @escaping () -> T) {
        self.sheetContent = content()
        self.detents = detents
        self.smallestUndimmedDetentIdentifier = smallestUndimmedDetentIdentifier
        self.prefersEdgeAttachedInCompactHeight = prefersEdgeAttachedInCompactHeight
        self.prefersScrollingExpandsWhenScrolledToEdge = prefersScrollingExpandsWhenScrolledToEdge
        self._isPresented = isPresented
    }
    func body(content: Content) -> some View {
        ZStack{
            content
            CustomSheet_UI(isPresented: $isPresented, detents: detents, smallestUndimmedDetentIdentifier: smallestUndimmedDetentIdentifier, prefersScrollingExpandsWhenScrolledToEdge: prefersScrollingExpandsWhenScrolledToEdge, prefersEdgeAttachedInCompactHeight: prefersEdgeAttachedInCompactHeight, content: {sheetContent}).frame(width: 0, height: 0)
        }
    }
}
@available(iOS 15.0, *)
extension View {
    func adaptiveSheet<T: View>(isPresented: Binding<Bool>, detents : [UISheetPresentationController.Detent] = [.medium(), .large()], smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier? = .medium, prefersScrollingExpandsWhenScrolledToEdge: Bool = false, prefersEdgeAttachedInCompactHeight: Bool = true, @ViewBuilder content: @escaping () -> T)-> some View {
        modifier(AdaptiveSheet(isPresented: isPresented, detents : detents, smallestUndimmedDetentIdentifier: smallestUndimmedDetentIdentifier, prefersScrollingExpandsWhenScrolledToEdge: prefersScrollingExpandsWhenScrolledToEdge, prefersEdgeAttachedInCompactHeight: prefersEdgeAttachedInCompactHeight, content: content))
    }
}

@available(iOS 15.0, *)
struct CustomSheet_UI<Content: View>: UIViewControllerRepresentable {
    
    let content: Content
    @Binding var isPresented: Bool
    let detents : [UISheetPresentationController.Detent]
    let smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier?
    let prefersScrollingExpandsWhenScrolledToEdge: Bool
    let prefersEdgeAttachedInCompactHeight: Bool
    
    init(isPresented: Binding<Bool>, detents : [UISheetPresentationController.Detent] = [.medium(), .large()], smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier? = .medium, prefersScrollingExpandsWhenScrolledToEdge: Bool = false, prefersEdgeAttachedInCompactHeight: Bool = true, @ViewBuilder content: @escaping () -> Content) {
        self.content = content()
        self.detents = detents
        self.smallestUndimmedDetentIdentifier = smallestUndimmedDetentIdentifier
        self.prefersEdgeAttachedInCompactHeight = prefersEdgeAttachedInCompactHeight
        self.prefersScrollingExpandsWhenScrolledToEdge = prefersScrollingExpandsWhenScrolledToEdge
        self._isPresented = isPresented
    }
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    func makeUIViewController(context: Context) -> CustomSheetViewController<Content> {
        let vc = CustomSheetViewController(coordinator: context.coordinator, detents : detents, smallestUndimmedDetentIdentifier: smallestUndimmedDetentIdentifier, prefersScrollingExpandsWhenScrolledToEdge:  prefersScrollingExpandsWhenScrolledToEdge, prefersEdgeAttachedInCompactHeight: prefersEdgeAttachedInCompactHeight, content: {content})
        return vc
    }
    
    func updateUIViewController(_ uiViewController: CustomSheetViewController<Content>, context: Context) {
        if isPresented{
            uiViewController.presentModalView()
        }else{
            uiViewController.dismissModalView()
        }
    }
    class Coordinator: NSObject, UIAdaptivePresentationControllerDelegate {
        var parent: CustomSheet_UI
        init(_ parent: CustomSheet_UI) {
            self.parent = parent
        }
        //Adjust the variable when the user dismisses with a swipe
        func presentationControllerDidDismiss(_ presentationController: UIPresentationController) {
            if parent.isPresented{
                parent.isPresented = false
            }
            
        }
        
    }
}

@available(iOS 15.0, *)
class CustomSheetViewController<Content: View>: UIViewController {
    let content: Content
    let coordinator: CustomSheet_UI<Content>.Coordinator
    let detents : [UISheetPresentationController.Detent]
    let smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier?
    let prefersScrollingExpandsWhenScrolledToEdge: Bool
    let prefersEdgeAttachedInCompactHeight: Bool
    private var isLandscape: Bool = UIDevice.current.orientation.isLandscape
    init(coordinator: CustomSheet_UI<Content>.Coordinator, detents : [UISheetPresentationController.Detent] = [.medium(), .large()], smallestUndimmedDetentIdentifier: UISheetPresentationController.Detent.Identifier? = .medium, prefersScrollingExpandsWhenScrolledToEdge: Bool = false, prefersEdgeAttachedInCompactHeight: Bool = true, @ViewBuilder content: @escaping () -> Content) {
        self.content = content()
        self.coordinator = coordinator
        self.detents = detents
        self.smallestUndimmedDetentIdentifier = smallestUndimmedDetentIdentifier
        self.prefersEdgeAttachedInCompactHeight = prefersEdgeAttachedInCompactHeight
        self.prefersScrollingExpandsWhenScrolledToEdge = prefersScrollingExpandsWhenScrolledToEdge
        super.init(nibName: nil, bundle: .main)
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    func dismissModalView(){
        dismiss(animated: true, completion: nil)
    }
    func presentModalView(){
        
        let hostingController = UIHostingController(rootView: content)
        
        hostingController.modalPresentationStyle = .popover
        hostingController.presentationController?.delegate = coordinator as UIAdaptivePresentationControllerDelegate
        hostingController.modalTransitionStyle = .coverVertical
        if let hostPopover = hostingController.popoverPresentationController {
            hostPopover.sourceView = super.view
            let sheet = hostPopover.adaptiveSheetPresentationController
            //As of 13 Beta 4 if .medium() is the only detent in landscape error occurs
            sheet.detents = (isLandscape ? [.large()] : detents)
            sheet.largestUndimmedDetentIdentifier =
            smallestUndimmedDetentIdentifier
            sheet.prefersScrollingExpandsWhenScrolledToEdge =
            prefersScrollingExpandsWhenScrolledToEdge
            sheet.prefersEdgeAttachedInCompactHeight =
            prefersEdgeAttachedInCompactHeight
            sheet.widthFollowsPreferredContentSizeWhenEdgeAttached = true
            
        }
        if presentedViewController == nil{
            present(hostingController, animated: true, completion: nil)
        }
    }
    /// To compensate for orientation as of 13 Beta 4 only [.large()] works for landscape
    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        if UIDevice.current.orientation.isLandscape {
            isLandscape = true
            self.presentedViewController?.popoverPresentationController?.adaptiveSheetPresentationController.detents = [.large()]
        } else {
            isLandscape = false
            self.presentedViewController?.popoverPresentationController?.adaptiveSheetPresentationController.detents = detents
        }
    }
}

@available(iOS 15.0, *)
struct CustomSheetView_Previews: PreviewProvider {
    static var previews: some View {
        CustomSheetParentView()
    }
}

Answer 10

至少在 iOS 14、Swift 5、Xcode 12.5 中，我只需将 UIActivityViewController 包装在另一个视图控制器中即可相当轻松地完成此操作。它不需要检查视图层次结构或使用任何 3rd 方库。唯一骇人听闻的部分是异步呈现视图控制器，这甚至可能不是必需的。有更多 SwiftUI 经验的人或许可以提供改进建议。

import Foundation
import SwiftUI
import UIKit

struct ActivityViewController: UIViewControllerRepresentable {
        
    @Binding var shareURL: URL?
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    func makeUIViewController(context: Context) -> some UIViewController {
        let containerViewController = UIViewController()
        
        return containerViewController

    }
    
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        guard let shareURL = shareURL, context.coordinator.presented == false else { return }
        
        context.coordinator.presented = true

        let activityViewController = UIActivityViewController(activityItems: [shareURL], applicationActivities: nil)
        activityViewController.completionWithItemsHandler = { activity, completed, returnedItems, activityError in
            self.shareURL = nil
            context.coordinator.presented = false

            if completed {
                // ...
            } else {
                // ...
            }
        }
        
        // Executing this asynchronously might not be necessary but some of my tests
        // failed because the view wasn't yet in the view hierarchy on the first pass of updateUIViewController
        //
        // There might be a better way to test for that condition in the guard statement and execute this
        // synchronously if we can be be sure updateUIViewController is invoked at least once after the view is added
        DispatchQueue.main.asyncAfter(deadline: .now()) {
            uiViewController.present(activityViewController, animated: true)
        }
    }
    
    class Coordinator: NSObject {
        let parent: ActivityViewController
        
        var presented: Bool = false
        
        init(_ parent: ActivityViewController) {
            self.parent = parent
        }
    }
    
}

struct ContentView: View {
    
    @State var shareURL: URL? = nil
    
    var body: some View {
        ZStack {
            Button(action: { shareURL = URL(string: "https://apple.com") }) {
                Text("Share")
                    .foregroundColor(.white)
                    .padding()
            }
            .background(Color.blue)
            if shareURL != nil {
                ActivityViewController(shareURL: $shareURL)
            }
        }
        .frame(width: 375, height: 812)
    }
}

Answer 11

对于更通用的解决方案，我提出了以下想法： https://github.com/mtzaquia/UIKitPresentationModifier

这是一个通用修饰符，允许您在 SwiftUI 视图中使用 UIKit 演示文稿。

从那里开始，世界就是你的牡蛎。唯一的缺点是您可能需要将自定义环境值从 presenting 视图级联到 presenting 视图中。

myPresentingView
  .presentation(isPresented: $isPresented) {
    MyPresentedView()
  } controllerProvider: { content in
    let controller = UIHostingController(rootView: content)
    if #available(iOS 15, *) {
      if let sheet = controller.sheetPresentationController {
        sheet.preferredCornerRadius = 12
        sheet.prefersGrabberVisible = true
      }
    }
    
    return controller
  }