Improve UIA Provider Cleanup Logic for Virtual ListView Items

[LeafShi1]

Fixes #13922

Root Cause

When ListView.VirtualMode = true, the current implementation of ReleaseUiaProvider() iterates over all indices (Items.Count) and calls Items.GetItemByIndex().
This triggers OnRetrieveVirtualItem for every index, forcing creation of all virtual items even if they were never displayed or accessed.

Result in:
Severe performance degradation for large virtual lists (e.g., tens of thousands of items).
High memory pressure due to unnecessary ListViewItem instantiation.
UI freeze during control disposal.

Proposed changes

This PR improves the cleanup logic for UI Automation (UIA) providers in ListView when operating in VirtualMode = true. Specifically:

• Introduces a _uiaAccessedIndices tracking mechanism to record only the indices of items whose AccessibilityObject was created by UIA.
• Updates ReleaseUiaProvider to selectively release UIA providers only for accessed items, avoiding full traversal of VirtualListSize and improving performance.
• Ensures NotifyUiaCreated is called during AccessibilityObject creation to maintain accurate tracking.
• Prevents triggering RetrieveVirtualItem during cleanup, which previously caused unnecessary item creation and severe performance degradation in large virtual lists.

Customer Impact

• Improves performance and responsiveness when using ListView in virtual mode with large datasets

Regression?

• No

Risk

• Minimal

Screenshots

Before

When closing the form containing the ListView (in virtual mode), followed by closing the main form, the application experienced a noticeable delay.

BeforeChanges.mp4

After

When closing the form containing the ListView (in virtual mode), and subsequently closing the main form, the main form closes immediately with no noticeable delay.

AfterChanges.mp4

Test methodology

• Manually

Test environment(s)

• .net 10.0.0-rc.1.25507.102

Microsoft Reviewers: Open in CodeFlow

[codecov]

Codecov Report

❌ Patch coverage is 96.42857% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 77.15120%. Comparing base (e36dddd) to head (c0e5c79).
⚠️ Report is 7 commits behind head on main.

Additional details and impacted files

@@                 Coverage Diff                 @@
##                main      #13953         +/-   ##
===================================================
+ Coverage   77.15093%   77.15120%   +0.00027%     
===================================================
  Files           3276        3276                 
  Lines         645116      645141         +25     
  Branches       47705       47709          +4     
===================================================
+ Hits          497713      497734         +21     
+ Misses        143716      143712          -4     
- Partials        3687        3695          +8     

Flag	Coverage Δ
Debug	77.15120% <96.42857%> (+0.00027%)	⬆️
integration	18.99715% <35.71429%> (+0.00740%)	⬆️
production	52.01777% <96.42857%> (+0.00417%)	⬆️
test	97.40835% <ø> (-0.00113%)	⬇️
unit	49.47502% <96.42857%> (+0.01445%)	⬆️

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[KlausLoeffelmann]

I think, with this approach, we are "unvirtualize" ListView items and prevent them from being GC-collected. Let's discuss this and make sure, I am not missing anything.

[LeafShi1]

with this approach, we are "unvirtualize" ListView items and prevent them from being GC-collected

@KlausLoeffelmann I updated the PR, please review it again. Added _uiaAccessedIndices to track only the indices accessed by UIA in virtual mode, _uiaAccessedIndices stores only integer indices, not ListViewItem objects. Since there is no strong reference to the actual items, the GC can still reclaim them when they are no longer used.