[Native AOT] v1.5.0-preview1 crashes when creating the column filter flyout

[HenryWu01]

Description:

WinUI.TableView v1.5.0-preview1 throws a XamlParseException when the column options/filter flyout is created in a Native AOT WinUI 3 application.

The exception is:

Cannot add instance of type 'Microsoft.UI.Xaml.Controls.MenuFlyoutItem'
to a collection of type
'Windows.Foundation.Collections.IVector`1<Microsoft.UI.Xaml.Controls.MenuFlyoutItemBase>'.
[Line: 0 Position: 0]

This appears to originate from TableViewFilterMenuFlyout.Items, which is declared as IList<MenuFlyoutItemBase>, while TableViewColumnHeader.xaml populates it with derived MenuFlyoutItem and MenuFlyoutSeparator instances. Under CsWinRT/Native AOT, the property is projected as IVector<MenuFlyoutItemBase>, and inserting the derived XAML objects fails during flyout creation.

This is different from the missing menu bindings discussed in #140: v1.5.0-preview1 gets past those binding issues, but the new filter flyout collection itself fails to materialize.

Steps to Reproduce:

1. Create a packaged WinUI 3 application targeting .NET 10.

2. Enable Native AOT:

   <PublishAot>true</PublishAot>

3. Reference WinUI.TableView v1.5.0-preview1.

4. Add a TableView with at least one bound column and leave column sorting/filtering enabled.

5. Run the application and open a column header's options/filter menu.

6. Observe the XamlParseException shown above.

A minimal table declaration is sufficient:

<tv:TableView ItemsSource="{x:Bind ViewModel.Items}"
              AutoGenerateColumns="False">
    <tv:TableView.Columns>
        <tv:TableViewTextColumn Header="Name"
                                Binding="{Binding Name}" />
    </tv:TableView.Columns>
</tv:TableView>

Expected behavior:

The column options/filter flyout should open and display its menu items without throwing an exception in a Native AOT application.

Screenshots:

Not applicable. The runtime exception and relevant type information are included above.

Environment:

• Package Version: 1.5.0-preview1
• WinAppSDK Version: host application 2.2.0; also reproduced after aligning the host to the WinAppSDK 1.8 line used by the package
• Target framework: net10.0-windows10.0.22621.0
• Runtime identifier: win-x64
• Deployment: packaged MSIX
• Native AOT: enabled

Contribution:

• I am willing to submit a PR to fix this issue