Fluent2 ContextMenu Won't Vertically Scroll

[robert-abeo]

Description

The Fluent2 ContextMenu doesn't support scrolling which is a mistake in the control template:

wpf/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/ContextMenu.xaml

Lines 41 to 45 in e16222f

	<StackPanel
	ClipToBounds="True"
	IsItemsHost="True"
	KeyboardNavigation.DirectionalNavigation="Cycle"
	Orientation="Vertical" />

Compare this to the MenuItem which is correct:

wpf/src/Microsoft.DotNet.Wpf/src/Themes/PresentationFramework.Fluent/Styles/MenuItem.xaml

Lines 107 to 109 in e16222f

	<ScrollViewer CanContentScroll="True" Style="{StaticResource MenuItemScrollViewerStyle}">
	<StackPanel IsItemsHost="True" KeyboardNavigation.DirectionalNavigation="Cycle" />
	</ScrollViewer>

The fix is simply:

                        <!-- Modified to support scrolling -->
                        <ScrollViewer
                            CanContentScroll="True"
                            HorizontalScrollBarVisibility="Disabled"
                            VerticalScrollBarVisibility="Auto">
                            <StackPanel
                                Orientation="Vertical"
                                ClipToBounds="True"
                                IsItemsHost="True"
                                KeyboardNavigation.DirectionalNavigation="Cycle" />
                        </ScrollViewer>

Reproduction Steps

See above

Expected behavior

Vertical scrolling is supported

Actual behavior

No vertical scrolling

Regression?

No response

Known Workarounds

No response

Impact

No response

Configuration

No response

Other information

No response

[dipeshmsft]

@robert-abeo, we are really grateful that you are giving the new Fluent styles a try and finding out issues in the templates. We will keep working iteratively for fixing the issues. We have worked on some of your issues and raised PR ( #9958 ) to fix it and will keep working on rest of the issues as well.