交互式弹出手势识别器应允许用户在滑过屏幕的一半以上(或这些行周围的内容)时返回导航堆栈中的上一个视图。在SwiftUI中,如果滑动距离不够,手势不会被取消。
SwiftUI: https://imgur.com/xxVnhY7
UIKit: https://imgur.com/f6WBUne
问题:
使用SwiftUI视图时是否可能获得UIKit行为?
尝试
我试图将UIHostingController嵌入UINavigationController内,但其行为与NavigationView完全相同。
struct ContentView: View {
var body: some View {
UIKitNavigationView {
VStack {
NavigationLink(destination: Text("Detail")) {
Text("SwiftUI")
}
}.navigationBarTitle("SwiftUI", displayMode: .inline)
}.edgesIgnoringSafeArea(.top)
}
}
struct UIKitNavigationView<Content: View>: UIViewControllerRepresentable {
var content: () -> Content
init(@ViewBuilder content: @escaping () -> Content) {
self.content = content
}
func makeUIViewController(context: Context) -> UINavigationController {
let host = UIHostingController(rootView: content())
let nvc = UINavigationController(rootViewController: host)
return nvc
}
func updateUIViewController(_ uiViewController: UINavigationController, context: Context) {}
}
SwipeNavigationController
文件:import UIKit
import SwiftUI
final class SwipeNavigationController: UINavigationController {
// MARK: - Lifecycle
override init(rootViewController: UIViewController) {
super.init(rootViewController: rootViewController)
}
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
delegate = self
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
delegate = self
}
override func viewDidLoad() {
super.viewDidLoad()
// This needs to be in here, not in init
interactivePopGestureRecognizer?.delegate = self
}
deinit {
delegate = nil
interactivePopGestureRecognizer?.delegate = nil
}
// MARK: - Overrides
override func pushViewController(_ viewController: UIViewController, animated: Bool) {
duringPushAnimation = true
super.pushViewController(viewController, animated: animated)
}
var duringPushAnimation = false
// MARK: - Custom Functions
func pushSwipeBackView<Content>(_ content: Content) where Content: View {
let hostingController = SwipeBackHostingController(rootView: content)
self.delegate = hostingController
self.pushViewController(hostingController, animated: true)
}
}
// MARK: - UINavigationControllerDelegate
extension SwipeNavigationController: UINavigationControllerDelegate {
func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
guard let swipeNavigationController = navigationController as? SwipeNavigationController else { return }
swipeNavigationController.duringPushAnimation = false
}
}
// MARK: - UIGestureRecognizerDelegate
extension SwipeNavigationController: UIGestureRecognizerDelegate {
func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
guard gestureRecognizer == interactivePopGestureRecognizer else {
return true // default value
}
// Disable pop gesture in two situations:
// 1) when the pop animation is in progress
// 2) when user swipes quickly a couple of times and animations don't have time to be performed
let result = viewControllers.count > 1 && duringPushAnimation == false
return result
}
}
与SwipeNavigationController
提供的here相同,并附加了pushSwipeBackView()
功能。
此功能需要一个SwipeBackHostingController
,我们将其定义为
import SwiftUI class SwipeBackHostingController<Content: View>: UIHostingController<Content>, UINavigationControllerDelegate { func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) { guard let swipeNavigationController = navigationController as? SwipeNavigationController else { return } swipeNavigationController.duringPushAnimation = false } override func viewWillDisappear(_ animated: Bool) { super.viewWillDisappear(animated) guard let swipeNavigationController = navigationController as? SwipeNavigationController else { return } swipeNavigationController.delegate = nil } }
然后我们将应用程序的SceneDelegate
设置为使用SwipeNavigationController
:
if let windowScene = scene as? UIWindowScene {
let window = UIWindow(windowScene: windowScene)
let hostingController = UIHostingController(rootView: ContentView())
window.rootViewController = SwipeNavigationController(rootViewController: hostingController)
self.window = window
window.makeKeyAndVisible()
}
最后在ContentView
中使用它:
struct ContentView: View {
func navController() -> SwipeNavigationController {
return UIApplication.shared.windows[0].rootViewController! as! SwipeNavigationController
}
var body: some View {
VStack {
Text("SwiftUI")
.onTapGesture {
self.navController().pushSwipeBackView(Text("Detail"))
}
}.onAppear {
self.navController().navigationBar.topItem?.title = "Swift UI"
}.edgesIgnoringSafeArea(.top)
}
}