SwiftUI：再次点击所选选项卡时弹出到根视图

起点是 TabView 中的 NavigationView。我正在努力寻找一个 SwiftUI 解决方案，以便在再次点击所选选项卡时弹出到导航堆栈中的根视图。在 SwiftUI 之前的时代，这很简单：

func tabBarController(_ tabBarController: UITabBarController, didSelect viewController: UIViewController) {
    let navController = viewController as! UINavigationController
    navController.popViewController(animated: true)
}

你知道如何在 SwiftUI 中实现同样的事情吗？

目前，我使用以下依赖于 UIKit 的解决方法：

if let windowScene = scene as? UIWindowScene {
    let window = UIWindow(windowScene: windowScene)
                
    let navigationController = UINavigationController(rootViewController: UIHostingController(rootView: MyCustomView() // -> this is a normal SwiftUI file
         .environment(\.managedObjectContext, context)))
    navigationController.tabBarItem = UITabBarItem(title: "My View 1", image: nil, selectedImage: nil)
                
    // add more controllers that are part of tab bar controller
                
    let tabBarController = UITabBarController()
    tabBarController.viewControllers = [navigationController /* ,  additional controllers */ ]
    
    window.rootViewController = tabBarController // UIHostingController(rootView: contentView)
    self.window = window
    window.makeKeyAndVisible()
}

这是可能的方法。为了TabView它提供与点击另一个选项卡然后返回相同的行为，因此提供持久的外观和感觉。

已测试并适用于 Xcode 11.2 / iOS 13.2

完整模块代码：

import SwiftUI

struct TestPopToRootInTab: View {
    @State private var selection = 0
    @State private var resetNavigationID = UUID()

    var body: some View {

        let selectable = Binding(        // << proxy binding to catch tab tap
            get: { self.selection },
            set: { self.selection = $0

                // set new ID to recreate NavigationView, so put it
                // in root state, same as is on change tab and back
                self.resetNavigationID = UUID()
        })

        return TabView(selection: selectable) {
            self.tab1()
                .tabItem {
                    Image(systemName: "1.circle")
                }.tag(0)
            self.tab2()
                .tabItem {
                    Image(systemName: "2.circle")
                }.tag(1)
        }
    }

    private func tab1() -> some View {
        NavigationView {
            NavigationLink(destination: TabChildView()) {
                Text("Tab1 - Initial")
            }
        }.id(self.resetNavigationID) // << making id modifiable
    }

    private func tab2() -> some View {
        Text("Tab2")
    }
}

struct TabChildView: View {
    var number = 1
    var body: some View {
        NavigationLink("Child \(number)",
            destination: TabChildView(number: number + 1))
    }
}

struct TestPopToRootInTab_Previews: PreviewProvider {
    static var previews: some View {
        TestPopToRootInTab()
    }
}