我想在 iPhone 上制作弹出框，我注意到.popover在 iPhone 中使用时它总是显示为工作表，但在 iPad 上它会显示为弹出框
所以我决定使用 UIKit 版本一切正常，直到我点击 Button 来更新视图
它将因此错误而崩溃
Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Application tried to present modally a view controller <_TtGC7SwiftUI19UIHostingControllerGVS_6HStackGVS_9TupleViewTGVS_6ButtonVS_4Text_S4_GS3_S4______: 0x7fd47b424df0> that is already being presented by <UIViewController: 0x7fd47b426200>.
我的代码：
struct PopoverViewModifier<PopoverContent>: ViewModifier where PopoverContent: View {
@Binding var isPresented: Bool
let onDismiss: (() -> Void)?
let content: () -> PopoverContent
func body(content: Content) -> some View {
content
.background(
Popover(
isPresented: self.$isPresented,
onDismiss: self.onDismiss,
content: self.content
)
)
}
}
extension View {
func popover<Content>(
isPresented: Binding<Bool>,
onDismiss: (() -> Void)? = nil,
content: @escaping () -> Content
) -> some View where Content: View {
ModifiedContent(
content: self,
modifier: PopoverViewModifier(
isPresented: isPresented,
onDismiss: onDismiss,
content: content
)
)
}
}
struct Popover<Content: View> : UIViewControllerRepresentable {
@Binding var isPresented: Bool
let onDismiss: (() -> Void)?
@ViewBuilder let content: () -> Content
func makeCoordinator() -> Coordinator {
return Coordinator(parent: self, content: self.content())
}
func makeUIViewController(context: Context) -> UIViewController {
return UIViewController()
}
func updateUIViewController(_ uiViewController: UIViewController, context: Context) {
let host = context.coordinator.host
if self.isPresented {
host.preferredContentSize = host.sizeThatFits(in: CGSize(width: Int.max , height: Int.max))
host.modalPresentationStyle = UIModalPresentationStyle.popover
host.popoverPresentationController?.delegate = context.coordinator
host.popoverPresentationController?.sourceView = uiViewController.view
host.popoverPresentationController?.sourceRect = uiViewController.view.bounds
uiViewController.present(host, animated: true, completion: nil)
}
else {
host.dismiss(animated: true, completion: nil)
}
}
class Coordinator: NSObject, UIPopoverPresentationControllerDelegate {
let host: UIHostingController<Content>
private let parent: Popover
init(parent: Popover, content: Content) {
self.parent = parent
self.host = UIHostingController(rootView: content)
}
func presentationControllerWillDismiss(_ presentationController: UIPresentationController) {
self.parent.isPresented = false
if let onDismiss = self.parent.onDismiss {
onDismiss()
}
}
func adaptivePresentationStyle(for controller: UIPresentationController) -> UIModalPresentationStyle {
return .none
}
}
}
我如何使用它：
struct ContentView: View {
@State var openChangeFont = false
@State var currentFontSize = 0
var body: some View {
NavigationView {
Text("Test")
.navigationBarTitleDisplayMode(.inline)
.toolbar {
Text("Popover")
.popover(isPresented: $openChangeFont, content: {
HStack {
Button(action: {
DispatchQueue.main.async {
currentFontSize += 2
}
}, label: {
Text("Increase")
})
Text("\(currentFontSize)")
Button(action: {
currentFontSize -= 2
}, label: {
Text("Decrease")
})
}
})
.onTapGesture {
openChangeFont.toggle()
}
}
}
}
}