TabItem-ComboBox MemoryLeak

[D-Bracket]

Description

If you create a UserControl, with an empty ComboBox () then use that UserControl in a TabItem of a TabControl, the UserControl is not beeing reclaimed by the GC after you Remove the TabItem.

Reproduction Steps

1. Create UserControl with ComboBox
2. Create TabControl in for example MainWindow
3. Add TabItem with UserControl as Content.
4. Remove the TabItem. (UserControl is not beeing reclaimed by GC)

Expected behavior

UserControl should be collected by GC.

Actual behavior

UserControl with a ComboBox is not getting garbage collected after removing TabItems from a TabControl, due to a handler set by the ItemContainerGenerator of the ComboBox (ItemContainerGenerator EventHandler).

Regression?

No response

Known Workarounds

No response

Impact

The severity of the leak of course depends on the UserControl.

Configuration

OS: Windows 10/11
.NET Version: .NET8
Visual Studio: VS2022
Architecture: x64

Other information

Minimal repro:
I have built repository showcasing the issue:
https://github.com/D-Bracket/WPF.MemoryLeak.Tests

[h3xds1nz]

@D-Bracket Using your repro, there's no memory leak. As you can see, I'm on tab item 25 and the previous ones have been collected.

First screenshot is triggering the collection early while always keeping 1 tab item, second is spawning about 40 of them, then removing them and waiting for GC to happen naturally.