Fixes#13922

Root Cause

WhenListView.VirtualMode = true, the current implementation of ReleaseUiaProvider() iterates over all indices (Items.Count) and callsItems.GetItemByIndex().
This triggersOnRetrieveVirtualItem 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 inVirtualMode = true. Specifically:

• Introduces a_uiaAccessedIndices tracking mechanism to record only the indices of items whoseAccessibilityObject was created by UIA.
• UpdatesReleaseUiaProvider to selectively release UIA providers only for accessed items, avoiding full traversal ofVirtualListSize and improving performance.
• EnsuresNotifyUiaCreated is called duringAccessibilityObject creation to maintain accurate tracking.
• Prevents triggeringRetrieveVirtualItem 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.

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.

Test methodology

• Manually

Test environment(s)

• .net 10.0.0-rc.1.25507.102

Microsoft Reviewers:Open in CodeFlow