我遵循Apple的示例interfacing-with-uikit在SwiftUI中使用PageView。我想在我的应用程序中实现它。场景是在MovieView
中,当用户点击图像列表的图像时,它将触发以视图和选定索引为参数的PageView
调用。
但是当我单击图像列表的任何项目时,它始终显示带有第一个元素的页面视图。我尝试在init()
的PageView
中更改它,但是它不起作用。
在控制台中,我尝试打印某些内容,但我发现currentPage没有更改。
ReceivedIdx: 0
Current page: 1
ReceivedIdx: 3
Current page: 1
ReceivedIdx: 5
Current page: 1
当前,currentPage
连接在PageView
和PageViewCollection
之间,但是如何将selectedIdx
与它们连接?因为这是为其选择图像的触发点。
...
private struct ImageList: View {
var images: [ImageViewModel]
@State private var showSheet = false
@State private var selectedIdx = 0
var body: some View {
VStack(alignment: .leading) {
Text("Images")
.font(.headline)
ScrollView(.horizontal) {
HStack(alignment: .top, spacing: 6) {
ForEach(0..<images.count, id: \.self) { i in
KFImage(source: .network(self.images[i].fileURL))
.resizable()
.frame(width: 200)
.aspectRatio(1.77, contentMode: .fit)
.onTapGesture {
self.selectedIdx = i
self.showSheet.toggle()
}
}
}.sheet(isPresented: $showSheet) {
PageView(self.images.map { PresentedImageView(image: $0) }, selectedIdx: self.selectedIdx)
}
}.frame(height: 120)
}
.padding(.horizontal).padding(.bottom)
}
}
private struct PresentedImageView: View {
var image: ImageViewModel
var body: some View {
KFImage(source: .network(image.fileURL))
.resizable()
//.frame(width: gr.size.width - 6, alignment: .center)
.aspectRatio(1.77, contentMode: .fit)
}
}
...
import SwiftUI
struct PageView<Page: View>: View {
var viewControllers: [UIHostingController<Page>]
var selectedIdx = 0
@State var currentPage = 1
init(_ views: [Page], selectedIdx: Int) {
self.viewControllers = views.map { UIHostingController(rootView: $0) }
self.currentPage = selectedIdx
print("ReceivedIdx: \(selectedIdx)")
print("Current page: \(currentPage)")
}
var body: some View {
PageViewController(controllers: viewControllers, currentPage: $currentPage)
}
}
//struct PageView_Previews: PreviewProvider {
// static var previews: some View {
// PageView(features.map { FeatureCard(landmark: $0) })
// .aspectRatio(3/2, contentMode: .fit)
// }
//}
import SwiftUI
import UIKit
struct PageViewController: UIViewControllerRepresentable {
var controllers: [UIViewController]
@Binding var currentPage: Int
func makeCoordinator() -> Coordinator {
Coordinator(self)
}
func makeUIViewController(context: Context) -> UIPageViewController {
let pageViewController = UIPageViewController(transitionStyle: .scroll,
navigationOrientation: .horizontal)
pageViewController.dataSource = context.coordinator
pageViewController.delegate = context.coordinator
return pageViewController
}
func updateUIViewController(_ pageViewController: UIPageViewController, context: Context) {
pageViewController.setViewControllers([controllers[currentPage]], direction: .forward, animated: true)
}
class Coordinator: NSObject, UIPageViewControllerDataSource, UIPageViewControllerDelegate {
var parent: PageViewController
init(_ pageViewController: PageViewController) {
self.parent = pageViewController
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerBefore viewController: UIViewController) -> UIViewController? {
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index == 0 {
return parent.controllers.last
}
return parent.controllers[index - 1]
}
func pageViewController(_ pageViewController: UIPageViewController, viewControllerAfter viewController: UIViewController) -> UIViewController? {
guard let index = parent.controllers.firstIndex(of: viewController) else {
return nil
}
if index + 1 == parent.controllers.count {
return parent.controllers.first
}
return parent.controllers[index + 1]
}
func pageViewController(_ pageViewController: UIPageViewController, didFinishAnimating finished: Bool, previousViewControllers: [UIViewController], transitionCompleted completed: Bool) {
if completed,
let visibleViewController = pageViewController.viewControllers?.first,
let index = parent.controllers.firstIndex(of: visibleViewController)
{
parent.currentPage = index
}
}
}
}
最后,我今天早上找到了答案!