返回时swiftUI bottomBar 工具栏消失 [英] swiftUI bottomBar toolbar disappears when going back

问题描述

我有这些 swiftUI 视图并尝试使用 toolbar (bottomBar).当您启动应用程序时，它看起来不错，但是在使用导航链接转到 View2 后，然后返回主视图，工具栏消失了.当 NavigationLink 在列表中时会发生这种情况.如果您不使用列表(将导航链接放在 VStack 或类似内容中)，它会按预期工作，当您返回初始视图时，工具栏会重新出现.有没有办法解决这个问题?

I have these swiftUI views and trying to use the toolbar (bottomBar). When you launch the app it appears fine, but after going to View2 using he navigationLink and then go back to the main view the toolbar disappears. It happens when the NavigationLink being inside the list. If you don't use a list (put the navigation link inside a VStack or similar) it works as expected and the toolbar reappears when you go back to the initial view. Is there a way to fix this?

import SwiftUI

struct View2: View {
    var body: some View {
        VStack{
            Text("View2")
        }
        
    }
}

struct ContentView: View {
    var body: some View {
        NavigationView{
            List{
                NavigationLink(destination: View2()) {
                    Text("go to View2")
                }
                
            }
            .toolbar(content: {
                ToolbarItem(placement: .bottomBar, content: {
                    Text("toolbar item 1")
                })
            })
        }
        .navigationViewStyle(StackNavigationViewStyle())
            
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

推荐答案

这是已知错误.这是可能的解决方法 - View2 上的强制刷新消失(使用 Xcode 12.1/iOS 14.1 测试)

This is known bug. Here is possible workaround - force refresh on View2 disappeared (tested with Xcode 12.1 / iOS 14.1)

struct ContentView: View {
    @State private var refresh = UUID()

    var body: some View {
        NavigationView{
            List{
                NavigationLink(destination:
                        View2().onDisappear { refresh = UUID() }) { // << here !!
                    Text("go to View2")
                }
            }
            .toolbar(content: {
                 ToolbarItem(placement: .bottomBar, content: {
                      Text("toolbar item 1")
                 })
            }).id(refresh)                     // << here !!

        }
        .navigationViewStyle(StackNavigationViewStyle())
    }
}

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