[.NET10]I9-Scroll mode "KeepLastItemInView" does not keep the last item at the end of the displayed list when adding new items.

[Zhanglirong-Winnie]

Description

I9-Scroll mode "KeepLastItemInView" does not keep the last item at the end of the displayed list when adding new items.

Affected case:
I9 -Control scroll position when new items are added.

Steps to Reproduce

1. Deploy https://devdiv.visualstudio.com/Pkgs/_git/VS.TestAssets.Xaml?path=/Assets/Projects/ManualMauiTests on Mac/iOS platform.
2. Click I9_Scrolling -> Scroll mode when adding items
3. Set UpdatingScrollMode to KeepLastItemInView

Actual Behavior:
Scroll mode "KeepLastItemInView" does not keep the last item at the end of the displayed list when adding new items.
Maccatalyst:

iOS:

Expected Behavior:
The last item was kept in the list displayed when new items are added.

Link to public reproduction project repository

https://devdiv.visualstudio.com/Pkgs/_git/VS.TestAssets.Xaml?path=/Assets/Projects/ManualMauiTests

Version with bug

10.0.0-preview.3.25176.18

Is this a regression from previous behavior?

Yes, this is a regression. The issue cannot be repro on 10.0.0-preview.2.25153.5 & 9.0.50 & 9.0.40 & 9.0.0 & 8.0.100.

Affected platforms

iOS, macOS

[similar-issues-ai]

We've found some similar issues:

• [MAUI]I9_ Scrolling- Try scrolling down and when new items are added the first item does not kept in the displayed list. #26810 , similarity score: 90%

If any of the above are duplicates, please consider closing this issue out and adding additional context in the original issue.

Note: You can give me feedback by 👍 or 👎 this comment.

[PureWeen]

@Zhanglirong-Winnie can you validate this against nightly? So, the MAUI 9.0.60 builds?

[kubaflo]

I think the issue is that the CV2 doesn't implement KeepLastItemInView

[Zhanglirong-Winnie]

Hi, @PureWeen
I verified that this issue does not repro on the latest nightly version 9.0.60-ci.main.25176.1.

[PureWeen]

@Zhanglirong-Winnie is this CollectionView1 or COllectionView2?

Can you retest on both just to be sure
It looks like this behavior isn't implemented on CV2

So I'm curious if you were testing on CV2 here and then switched to CV1 for the test of the platforms

[Zhanglirong-Winnie]

Hi @PureWeen
Thank you for your reply again.
I have verified this issue again in .NET10, and it can be reproduced on both CV1 and CV2 versions.

[PureWeen]

@Zhanglirong-Winnie can you clarify if your validation here applies to CV1 and/or CV2?

Yes, this is a regression. The issue cannot be repro on 10.0.0-preview.2.25153.5 & 9.0.50 & 9.0.40 & 9.0.0 & 8.0.100.

[PureWeen]

This appears to be working fine on 9.0.60-ci.main.25208.3

[Zhanglirong-Winnie]

@Zhanglirong-Winnie can you clarify if your validation here applies to CV1 and/or CV2?

Yes, this is a regression. The issue cannot be repro on 10.0.0-preview.2.25153.5 & 9.0.50 & 9.0.40 & 9.0.0 & 8.0.100.

This issue repro in both CV1 and CV2 versions 10.0.0-preview.3.25176.18.