ListBox items' accessible objects are leaking in memory

[dmitrii-drobotov]

.NET version

.NET 7.0 Preview 4

Did it work in .NET Framework?

No

Did it work in any of the earlier releases of .NET Core or .NET 5+?

No

Issue description

ListBox items' accessible objects are left in memory after the ListBox control instance with its items was inspected with accessibility tool (like Accessibility Insights or Inspect) and the form with ListBox is closed, garbage is collected, but accessibility tool is still opened. Same applies for case when ListBox item is removed from ListBox.

Memory snapshot in VS:

Steps to reproduce

1. Create a parent form with two buttons: one will be opening a child form with the ListBox control and the other will collect the garbage.
2. Press the second button to open the child form with ListBox.
3. Start the Accessibility Insights tools.
4. Run automated checks for the ListBox control using AI.
5. Close the child form.
6. Clear memory with the first button of the parent form.
7. DON'T close the AI tool.
8. Look for ListBoxItemAccessibleObject accessible objects left in memory (using WinDbg, or dotMemory, or another suitable tool).

Sample app: ListBoxSample.zip

[dreddy-work]

@dmitrii-drobotov , we believe you are working on it hence, assigned to you.