Either pane or content must be provided🐛

[StevenHX]

Either pane or content must be provided
'package:fluent_ui/src/controls/navigation/navigation_view/view.dart':
Failed assertion: line 55 pos 11: '(pane != null && content == null) ||
(pane == null && content != null)'

but i have already set the navigation pane, like this:

NavigationView (
content: const Text("111111"),
pane: NavigationPane(
selected: index,
onChanged: (i) => setState(() => index = i),
displayMode: PaneDisplayMode.open,
size: const NavigationPaneSize(
openWidth: 150,
),
header: const Text("1111"),
items: [
PaneItem(
icon: const Icon(FluentIcons.icon_sets_flag),
title: const Text("首页"),
body: const Text("11")),
PaneItemSeparator(),
PaneItem(
icon: const Icon(FluentIcons.e_discovery),
title: const Text("新闻"),
body: const Text("11")),
]),
)

[StevenHX]

BREAKING Removed NavigationBody. Use PaneItem.body instead (#510/#531):
Before:

NavigationView(
pane: NavigationPane(
items: [
PaneItem(icon: Icon(FluentIcons.add)),
PaneItem(icon: Icon(FluentIcons.add)),
PaneItem(icon: Icon(FluentIcons.add)),
],
),
content: NavigationBody(
children: [
_Item1(),
_Item2(),
_Item3(),
],
),
),
Now:

NavigationView(
...
pane: NavigationPane(
items: [
PaneItem(
icon: Icon(FluentIcons.add),
body: _Item1(),
),
PaneItem(
icon: Icon(FluentIcons.add),
body: _Item2(),
),
PaneItem(
icon: Icon(FluentIcons.add),
body: _Item3(),
),
],
),
),
Or if you don't have a pane, you can use the content like the following:

NavigationView(
content: ScaffoldPage(
header: PageHeader(
title: titleRow,
),
content: child,
),
),
either one attribute of pane or content must not be null