SwiftUI - 表单中的 NavigationLink 单元格在详细信息弹出后保持突出显示

Question

In iOS 14, it appears that NavigationLink s do not become deselected after returning in a Form context. This is also true for Form Picker s and anything else that causes the presentation of another View from a list (giving a highlight context to the presenting cell).

I didn't notice this behaviour in iOS 13.

Is there a way to 'deselect' the highlighted row once the other view is dismissed?

Example code:

struct ContentView: View {

    var body: some View {
        Form {
            NavigationLink(destination: Text("Detail")) {
                Text("Link")
            } 
        }
    }

}

(Different) Example visual:

Answer 1

In my case this behaviour appeared when using any Viewcontent (eg Text(), Image(), ...) between my NavigationView and List/Form .

var body: some View {
    
    NavigationView {
        VStack {
            Text("This text DOES make problems.")
            List {
                NavigationLink(destination: Text("Doesn't work correct")) {
                    Text("Doesn't work correct")
                }
            }
        }
    }
}

Putting the Text() beneath the List does not make any problems:

var body: some View {
    
    NavigationView {
        VStack {
            List {
                NavigationLink(destination: Text("Does work correct")) {
                    Text("Does work correct")
                }
            }
            Text("This text doesn't make problems.")
        }
    }
}

This is definitely a XCode 12 bug. As more people report this, as earlier it gets resolved.

Answer 2

I have also run into this issue and believed I found the root cause in my case.

In my case I had.a structure like the following:

struct Page1View: View {
    var body: some View {
        NavigationView {
            List {
                NavigationLink("Page 2", destination: Page2View())
            }
                .listStyle(GroupedListStyle())
                .navigationBarTitle("Page 1")
        }
    }
}

struct Page2View: View {
    var body: some View {
        List {
            NavigationLink("Page 3", destination: Text("Page 3"))
        }
            .listStyle(GroupedListStyle())
            .navigationBarTitle("Page 2")
    }
}

This issue would occur on the NavigationLink to Page 3. In the console output this error was showing when that link was used:

2021-02-13 16:41:00.599844+0000 App[59157:254215] [Assert] displayModeButtonItem is internally managed and not exposed for DoubleColumn style. Returning an empty, disconnected UIBarButtonItem to fulfill the non-null contract.

I discovered that I needed to apply .navigationViewStyle(StackNavigationViewStyle()) to the NavigationView and this solved the problem.

Ie

struct Page1View: View {
    var body: some View {
        NavigationView {
            List {
                NavigationLink("Page 2", destination: Page2View())
            }
                .listStyle(GroupedListStyle())
                .navigationBarTitle("Page 1")
        }
            .navigationViewStyle(StackNavigationViewStyle())
    }
}

Answer 3

Been fighting this issue half day today and came to this post that helped me to understand that issue appears if Text , Button or something else placed between NavigationView and in my case List . And I found solution that worked for me. Just add .zIndex() for the item. .zIndex() must be higher than for List Tried with Xcode 12.5 .

var body: some View {
    NavigationView {
        VStack {
            Text("This text DOES make problems.")
                .zIndex(1.0)
            List {
                NavigationLink(destination: Text("Doesn't work correct")) {
                    Text("Doesn't work correct")
                }
            }
        }
    }
}

Answer 4

I did a bit more tinkering, it turns out this was caused due by having the UIHostingController being nested in a UINavigationController and using that navigation controller. Changing the navigation stack to use a SwiftUI NavigationView instead resolved this issue.

Similar to what @pawello2222 says in the question comments, I think the underlying cause is something to do with SwiftUI not understanding the proper navigation hierarchy when the external UINavigationController is used.

This is just one instance where this is fixed though, I'm still experiencing the issue in various other contexts depending on how my view is structured.

I've submitted an issue report FB8705430 to Apple, so hopefully this is fixed sometime soon.

Before (broken):

struct ContentView: View {
    var body: some View {
        Form {
             NavigationLink(destination: Text("test")) {
                 Text("test")
             }
        }
    }
}

// (UIKit presentation context)
let view = ContentView() 
let host = UIHostingController(rootView: view)
let nav = UINavigationController(rootViewController: host)
present(nav, animated: true, completion: nil)

After (working):

struct ContentView: View {
    var body: some View {
        NavigationView {
            Form {
                NavigationLink(destination: Text("test")) {
                    Text("test")
                }
            }
        }
    }
}

// (UIKit presentation context)
let view = ContentView()
let host = UIHostingController(rootView: view)
present(host, animated: true, completion: nil)

Answer 5

This is definitely a bug in List , for now, my work-around is refreshing the List by changing the id, like this:

struct YourView: View {
    @State private var selectedItem: String?
    @State private var listViewId = UUID()

    var body: some View {
            List(items, id: \.id) {
                NavigationLink(destination: Text($0.id), 
                               tag: $0.id, 
                               selection: $selectedItem) {
                  Text("Row \($0.id)")
                }
            }
            .id(listViewId)
            .onAppear {
                if selectedItem != nil {
                    selectedItem = nil
                    listViewId = UUID()
                }
            }
    } 
}

I made a modifier based on this that you can use:

struct RefreshOnAppearModifier<Tag: Hashable>: ViewModifier {
    @State private var viewId = UUID()
    @Binding var selection: Tag?
    
    func body(content: Content) -> some View {
        content
            .id(viewId)
            .onAppear {
                if selection != nil {
                    viewId = UUID()
                    selection = nil
                }
            }
    }
}

extension View {
    func refreshOnAppear<Tag: Hashable>(selection: Binding<Tag?>? = nil) -> some View {
        modifier(RefreshOnAppearModifier(selection: selection ?? .constant(nil)))
    }
}

use it like this:

List { ... }
  .refreshOnAppear(selection: $selectedItem)

Answer 6

I managed to solve it by adding ids to the different components of the list, using binding and resetting the binding on .onDisappear

struct ContentView: View {
    @State var selection: String? = nil

    var body: some View {
        NavigationView {
            VStack {
                Text("Hello, world!")
                    .padding()
                List {
                    Section {
                        NavigationLink( destination: Text("Subscreen1"), tag: "link1", selection: $selection ) {
                            Text("Subscreen1")
                        }.onDisappear {
                            self.selection = nil
                        }
                        NavigationLink( destination: Text("Subscreen2"), tag: "link2", selection: $selection ) {
                            Text("Subscreen2")
                        }.onDisappear {
                            self.selection = nil
                        }
                    }.id("idSection1")
                }
                .id("idList")
            }
        }
    }
}

Answer 7

I've also run into this issue and it seemed related to sheets as mentioned here .

My solution was to swizzle UITableView catch selections, and deselect the cell. The code for doing so is here . Hopefully this will be fixed in future iOS.

Answer 8

This is the workaround I've been using until this List issue gets fixed. Using the Introspect library, I save the List's UITableView.reloadData method and call it when it appears again.

import SwiftUI
import Introspect

struct MyView: View {

    @State var reload: (() -> Void)? = nil

    var body: some View {
        NavigationView {
            List {
                NavigationLink("Next", destination: Text("Hello"))
            }.introspectTableView { tv in
                self.reload = tv.reloadData
            }.onAppear {
                self.reload?()
            }
        }
    }
}

Answer 9

Adding .navigationViewStyle(StackNavigationViewStyle()) to NavigationView fixed it for me.

Suggested in this thread: https://developer.apple.com/forums/thread/660468

Answer 10

This is my solution to this issue.

// This in a stack in front of list, disables large navigation title from collapsing by disallowing list from scrolling on top of navigation title
public struct PreventCollapseView: View { 

    @State public var viewColor: Color?

    public init(color: Color? = nil) {
        self.viewColor = color
    }
    
    public var body: some View {
        Rectangle()
            .fill(viewColor ?? Color(UIColor(white: 0.0, alpha: 0.0005)))
            .frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 1)
    }
}

// handy modifier..
extension List {
    
    public func uncollapsing(_ viewUpdater: Bool) -> some View {
        
        VStack(spacing: 0.0) {
            Group {
                PreventCollapseView()
                self
            }.id(viewUpdater)
        }
    }
}

struct TestView: View {

    @State var updater: Bool = false
    
    var body: some View {

        List {
            Text("Item one")
            Text("Item two")
            Text("Manually refresh")
                .onTapGesture { DispatchQueue.main.async { updater.toggle() } }
                .onAppear { print("List was refreshed") }
        }
        .uncollapsing(updater)
        .clipped()
        .onAppear { DispatchQueue.main.async { updater.toggle() }} // Manually refreshes list always when re-appearing/appearing

    }
}

Add a NavigationView, configure for largeTitle, and embed TestView and it's all set. Toggle updater to refresh.

Answer 11

Having the same Problem. The weird thing is, that the exact same code worked in iOS13. I'm having this issue with a simple list:

struct TestList: View {
    let someArray = ["one", "two", "three", "four", "five"] 
    var body: some View {
        List(someArray, id: \.self) { item in 
                NavigationLink(
                    destination: Text(item)) {
                    Text(item)
                }.buttonStyle(PlainButtonStyle()) 
        }.navigationBarTitle("testlist") 
    }
}

This is embedded in:

struct ListControllerView: View {
    @State private var listPicker = 0
    var body: some View {
        NavigationView{
            Group{
                VStack{
                    Picker(selection: $listPicker, label: Text("Detailoverview")) {
                        Text("foo").tag(0)
                        Text("bar").tag(1)
                        Text("TestList").tag(2)
                    }

This is inside a Tabbar.