Fixed issue with IncrementalLoadingCollection within AdvancedCollecti…

[k-g-nolan]

…onView

Fixes #642

Fixed issue #642 by changing how the ACV handles generic types. The change is not perfect, but I wanted to be as non-invasive as possible. Ideally, AdvancedCollectionView would be generically typed itself, but that would be a major change.

PR Type

What kind of change does this PR introduce?

Bugfix

What is the current behavior?

#642
The current behavior throws a NullReferenceException when IncrementalLoadingCollection is used as the source of the ACV. this happens because the first generic type argument of the IncrementalLoadingColleciton is not the type of the objects in the list, but rather the type of the IIncrementalSource used when constructing the ILC.

What is the new behavior?

The new behavior fixes this issue by removing the generic type check and replacing it with the default behavior, which is to use the type of the first object being compared. It's not the most elegant solution, but it's non-invasive.

PR Checklist

Please check if your PR fulfills the following requirements:

• Created a feature/dev branch in your fork (vs. submitting directly from a commit on main)
• Based off latest main branch of toolkit(https://github.com/CommunityToolkit/WindowsCommunityToolkit-design-assets)
• Contains NO breaking changes

Other information

[michael-hawker]

Thanks for the PR here. I'm not sure of a .NET convention for the ordering of generic types like this with multiples. But since IncrementalLoadingCollection is also in this same component, we can just check if the type is the collection and grab the proper type, then fallback to the existing logic. I think that'd be a less disruptive change for this specific scenario?

[k-g-nolan]

@michael-hawker I added a clause to the if statement to check if the source is an IncrementalLoadingCollection. Let me know how it looks.

[lhak]

This would reintroduce the crashes seen here: #78. Maybe AdvancedCollectionView could be changed to AdvancedCollectionView<T> to explicitly provide the type. I guess, this might also help for AOT support?