我已经获得了一个动作表，可以在iPhone设备上呈现良好的效果。但是它崩溃了iPad。说它需要弹出窗口的位置。有人对此代码有运气吗？我正在使用iOS 13 beta 3和xcode 11 beta 3.(这使用了呈现beta 2中不可用的Actionsheet的版本(
import SwiftUI
struct ContentView : View {
@State var showSheet = false
var body: some View {
VStack {
Button(action: {
self.showSheet.toggle()
}) {
Text("Show")
}
.presentation($showSheet) { () -> ActionSheet in
ActionSheet(title: Text("Hello"))
}
}
}
}
#if DEBUG
struct ContentView_Previews : PreviewProvider {
static var previews: some View {
ContentView()
}
}
#endif
可悲的是，此错误尚未修复iOS 13的最终版本。在开发人员论坛上提到了它，我已经对其提出了反馈(FB7397761(，而是针对当UIDevice.current.userInterfaceIdiom == .pad时使用其他UI。
对于记录，(无用的(异常消息是：
2019-10-21 11:26:58.205533-0400 LOOksTape[34365:1769883] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Your application has presented a UIAlertController (<UIAlertController: 0x7f826e094a00>) of style UIAlertControllerStyleActionSheet from _TtGC7SwiftUI19UIHostingController…
The modalPresentationStyle of a UIAlertController with this style is UIModalPresentationPopover.
You must provide location information for this popover through the alert controller's popoverPresentationController.
You must provide either a sourceView and sourceRect or a barButtonItem.
If this information is not known when you present the alert controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.'
作为解决方法，此popSheet功能将在iPad上显示一个弹出声，而在其他地方将显示一个ActionSheet：
public extension View {
/// Creates an `ActionSheet` on an iPhone or the equivalent `popover` on an iPad, in order to work around `.actionSheet` crashing on iPad (`FB7397761`).
///
/// - Parameters:
/// - isPresented: A `Binding` to whether the action sheet should be shown.
/// - content: A closure returning the `PopSheet` to present.
func popSheet(isPresented: Binding<Bool>, arrowEdge: Edge = .bottom, content: @escaping () -> PopSheet) -> some View {
Group {
if UIDevice.current.userInterfaceIdiom == .pad {
popover(isPresented: isPresented, attachmentAnchor: .rect(.bounds), arrowEdge: arrowEdge, content: { content().popover(isPresented: isPresented) })
} else {
actionSheet(isPresented: isPresented, content: { content().actionSheet() })
}
}
}
}
/// A `Popover` on iPad and an `ActionSheet` on iPhone.
public struct PopSheet {
let title: Text
let message: Text?
let buttons: [PopSheet.Button]
/// Creates an action sheet with the provided buttons.
public init(title: Text, message: Text? = nil, buttons: [PopSheet.Button] = [.cancel()]) {
self.title = title
self.message = message
self.buttons = buttons
}
/// Creates an `ActionSheet` for use on an iPhone device
func actionSheet() -> ActionSheet {
ActionSheet(title: title, message: message, buttons: buttons.map({ popButton in
// convert from PopSheet.Button to ActionSheet.Button (i.e., Alert.Button)
switch popButton.kind {
case .default: return .default(popButton.label, action: popButton.action)
case .cancel: return .cancel(popButton.label, action: popButton.action)
case .destructive: return .destructive(popButton.label, action: popButton.action)
}
}))
}
/// Creates a `.popover` for use on an iPad device
func popover(isPresented: Binding<Bool>) -> some View {
VStack {
ForEach(Array(buttons.enumerated()), id: .offset) { (offset, button) in
Group {
SwiftUI.Button(action: {
// hide the popover whenever an action is performed
isPresented.wrappedValue = false
// another bug: if the action shows a sheet or popover, it will fail unless this one has already been dismissed
DispatchQueue.main.async {
button.action?()
}
}, label: {
button.label.font(.title)
})
Divider()
}
}
}
}
/// A button representing an operation of an action sheet or popover presentation.
///
/// Basically duplicates `ActionSheet.Button` (i.e., `Alert.Button`).
public struct Button {
let kind: Kind
let label: Text
let action: (() -> Void)?
enum Kind { case `default`, cancel, destructive }
/// Creates a `Button` with the default style.
public static func `default`(_ label: Text, action: (() -> Void)? = {}) -> Self {
Self(kind: .default, label: label, action: action)
}
/// Creates a `Button` that indicates cancellation of some operation.
public static func cancel(_ label: Text, action: (() -> Void)? = {}) -> Self {
Self(kind: .cancel, label: label, action: action)
}
/// Creates an `Alert.Button` that indicates cancellation of some operation.
public static func cancel(_ action: (() -> Void)? = {}) -> Self {
Self(kind: .cancel, label: Text("Cancel"), action: action)
}
/// Creates an `Alert.Button` with a style indicating destruction of some data.
public static func destructive(_ label: Text, action: (() -> Void)? = {}) -> Self {
Self(kind: .destructive, label: label, action: action)
}
}
}
最后，如iOS 13.4所述，至少在beta中已经解决了这一点。警告矛盾的约束持续存在，但坠机已经消失了。现在，这是提出动作表的适当方法。
import SwiftUI
struct ContentView : View {
@State var showSheet = false
var body: some View {
VStack {
Button(action: {
self.showSheet.toggle()
}) {
Text("Show")
}
.actionSheet(isPresented: $showSheet, content: { ActionSheet(title: Text("Hello"))
})
}
}
}
struct ContentView_Previews : PreviewProvider {
static var previews: some View {
ContentView()
}
}
尝试此组件，它将在iPhone上显示一个Actionsheet，并在iPad和Mac上提供一个弹出声。https://github.com/andreamiotto/actionover
这是我对错误的解决方法 - 它维护iPhone设备的" ActionSheet"功能，但只需为iPad创建一个"警报"样式控制器
这对我的情况很简单，可能会帮助他人
var preferredStyle: UIAlertController.Style
if UIDevice.current.userInterfaceIdiom == .pad {
preferredStyle = .alert
}
else{
preferredStyle = .actionSheet
}
let cellMenu = UIAlertController(title: nil, message: "Bought Item?", preferredStyle: preferredStyle)
//Create actions
//Add Actions to menu
self.present(cellMenu, animated: true, completion: nil)
它是Beta的已知错误。只需等待修复即可。