问题
I've added a .toolbar to the top level of a NavigationView that will eventually be used to select items in a list without using swipe gestures (up button, down button, etc.). I also have a .navigationBar going on, to access other views for Account and Settings.
For the most part it's looking really good, but when I follow a NavigationLink (in .navigationBarItems) within NavigationView, and then use the built-in back navigation, my .toolbar disappears from the top level.
Am I putting the .toolbar in the wrong place? It feels like a problem with .navigationViewStyle(StackNavigationViewStyle()) because when I comment that out, the toolbar will not disappear upon navigation... but I don't like how the default behavior works in landscape so I'm relying on it.
import SwiftUI
struct ContentView: View {
var body: some View {
NavigationView {
List {
Group {
Section(header: Text("List Items").foregroundColor(.gray).font(.footnote)) {
Text("List Item One")
Text("List Item Two")
Text("List Item Three")
}
}
}.navigationTitle("Top Level List").navigationBarTitleDisplayMode(.inline)
.ignoresSafeArea(.all)
// MARK: NAVBAR
.navigationBarItems(
leading:
NavigationLink(destination: UserView()) {
Image(systemName: "person.crop.circle").font(.title2)
},
trailing:
NavigationLink(destination: SettingsView()) {
Image(systemName: "gear").font(.title2)
})
//MARK: - CONTENT NAV
.toolbar {
ToolbarItemGroup(placement: .bottomBar) {
Button(action: {}, label: {Label("Mute", systemImage: "speaker.slash.fill")})
Spacer()
Button(action: {}, label: {Label("Repeat", systemImage: "arrow.clockwise")})
Spacer()
Button(action: {}, label: {Label("Previous", systemImage: "arrow.up")})
Spacer()
Button(action: {}, label: {Label("Next", systemImage: "arrow.down")})
Spacer()
Button(action: {}, label: {Label("Select", systemImage: "arrow.right")})
}
}
}.navigationViewStyle(StackNavigationViewStyle())
}
}
struct UserView: View {
@State private var username: String = ""
@State private var password: String = ""
var body: some View {
Form {
TextField("Username", text: $username)
SecureField("Password", text: $password)
}
.navigationBarTitle("Account").font(.subheadline)
}
}
struct SettingsView: View {
@State private var setting1: String = ""
@State private var setting2: String = ""
var body: some View {
Form {
TextField("Setting One", text: $setting1)
SecureField("Setting Two", text: $setting2)
}
.navigationBarTitle("Settings").font(.subheadline)
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
来源：https://stackoverflow.com/questions/63956668/swiftui-toolbar-disappears-after-following-navigationlink-and-coming-back