Nullable Enums do not bind in XAML

[aritchie]

Description

Nullable enums fail to bind for a bindable property within a custom control. The setter isn't even hit.

Steps to Reproduce

1. Create a control that has a nullable enum as a bindable property
2. Create a page to use control
3. Create a viewmodel
4. Wire up binding and observe

Attached sample is a m

Link to public reproduction project repository

https://github.com/aritchie/maui_nullable_enum_repro

Version with bug

8.0.80 SR8

Is this a regression from previous behavior?

Not sure, did not test other versions

Last version that worked well

Unknown/Other

Affected platforms

iOS, Android

Affected platform versions

All

Did you find any workaround?

Don't use nullable enums. Add an unset/none value to the enum.

Relevant log output

No response

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[Redth]

@StephaneDelcroix @simonrozsival this looks binding related, perhaps a change from more recent trimming/aot work?

[simonrozsival]

I don't think this is related to any of the trimming/aot changes because most of those changes went into the net9.0 branch and this is .NET 8.

[jfversluis]

Unfortunately not fixed by #28550 and still an issue in the latest .NET 9 version.