NavigationLink Works Only for Once

问题

I was working on an application with login and after login there are categories listed. And under each category there are some items listed horizontally. The thing is after login, main page appears and everything is listed great. When you click on an item it goes to detailed screen but when you try to go back it just crashes. I found this flow Why does my SwiftUI app crash when navigating backwards after placing a `NavigationLink` inside of a `navigationBarItems` in a `NavigationView`? but i could not solve my problem. Since my project become complicated, I just wanted to practice navigation in swiftui and I created a new project. By the way I downloaded the latest xcode version 11.3. I wrote a simple code as follows:

NavigationView{
        NavigationLink(destination: Test()) {
            Text("Show Detail View")
        }
    .navigationBarTitle("title1")

And Test() view is as follows:

import SwiftUI

struct Test: View {
    var body: some View {
        Text("Hello, World!")
    }
}

struct Test_Previews: PreviewProvider {
    static var previews: some View {
        Test()
    }
}

As you can see it is really simple. I also tried similar examples on the internet but it does not work the way it suppose to work. When I run the project, I click the navigation link and it navigates to Test() view. Then I click back button and it navigates to the main page. However, when I click the navigation link second time, nothing happens. Navigation link works only once and after that nothing happens. It does not navigate, it des not throw any error. I am new to swiftui and everything is great but the navigation. I tried many examples and suggested solutions on the internet, but nothing seems to fix my issues.

回答1:

I was getting the same issue in my project too, when I was testing it in Xcode's simulator. However, when I launched the app on a real device (iPhone X with iOS 13.3), NavigationLink was working totally fine. So, it really does seem like Xcode's bug.

回答2:

As @Александр Грабовский said its seems like a Xcode 11.3 bug, I am encountering the same problem, you must downgrade or use some workaround like custom back button as below

struct ContentView: View {
    @State private var pushed: Bool = false

    var body: some View {

        NavigationView {
            VStack {
                Button("Show Detail View") {
                    self.pushed.toggle()
                }

                NavigationLink(destination: Test(pushed: $pushed), isActive: $pushed) { EmptyView() }
            }.navigationBarTitle("title1")
        }
    }
}
struct Test: View {
    @Binding var pushed: Bool
    var body: some View {
        Text("Hello, World!")
            .navigationBarBackButtonHidden(true)
            .navigationBarItems(leading: BackButton(label: "Back") {
                self.pushed = false
            })
    }
}
struct BackButton: View {
    let label: String
    let closure: () -> ()

    var body: some View {
        Button(action: { self.closure() }) {
            HStack {
                Image(systemName: "chevron.left")
                Text(label)
            }
        }
    }
}

来源：https://stackoverflow.com/questions/59279176/navigationlink-works-only-for-once

标签

ios

xcode

navigation

swiftui

navigationlink