Fix Expander in CollectionView on Apple

[VladislavAntonyuk]

Description of Change

Set valid size and invalidate layout of CollectionView

Linked Issues

• Fixes [BUG] Add CollectionView and ListView Support to Expander #742

PR Checklist

• Has a linked Issue, and the Issue has been approved(bug) or Championed (feature/proposal)
• Has tests (if omitted, state reason in description)
• Has samples (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Changes adhere to coding standard
• Documentation created or updated: https://github.com/MicrosoftDocs/CommunityToolkit/pull/XYZ

Additional information

[pictos]

I tried on my end, and that didn't fix for maccatalyst, as you can see in the video below

Expander_Workaround.mp4

[VladislavAntonyuk]

Thank you @pictos. Seems like Task.Delay before InvalidateLayout was not a good solution, that works on all devices. I reworked it. Please check if it works for you

[rmarinho]

We merged the change on MAUI

[VladislavAntonyuk]

We merged the change on MAUI

Thank you @rmarinho! Will it be included in the next release?

[rmarinho]

I don't think so, unless we backport the fix to net7

[pictos]

@VladislavAntonyuk before moving with this and the other PR that I opened, the fix didn't work well for ListView on maccatalyst

[VladislavAntonyuk]

@pictos the fix is only for CollectionView. I also saw back merge of .NET MAUI to avoid reflection.
I believe we should wait for that release to avoid the workarounds

[pictos]

I've two suggestions. I just focused on the Expander related changed

[brminnick]

@VladislavAntonyuk Can you update the docs, changing it to "Expander is not supported inside ListView" now that only ListView is not supported?

[AnthonyNjuguna]

This doesn't work if the collection has a header view.

var clickedCell = GetCellByPoint(cells, new CGPoint(tapLocation.Value.X, tapLocation.Value.Y));

the clickedCell always returns null.

[pictos]

@AnthonyNjuguna can you please open a new bug issue?