StatusStrip: ToolStripDropDown is detached from its ToolStripItem in KioskModeManager full-screen mode

[Olina-Zhang]

.NET version

.NET 11.0.100-preview.7.26365.114 + Private dlls built from Net11/Integration-2 branch of https://github.com/KlausLoeffelmann/winforms repo

Did it work in .NET Framework?

Yes

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

Not support, new feature

Issue description

When using KioskModeManager in full-screen mode, the drop-down menu of a ToolStripItem in StatusStrip is displayed in an incorrect position. Instead of appearing directly below the associated ToolStripItem, the drop-down is offset and appears detached from it.

The issue reproduces with both VisualStyleMode = Classic and VisualStyleMode = .NET11. And not repro in ToolStrip

Steps to reproduce

1. Create a WinForms application targeting .NET 11.
2. Enable KioskModeManager full-screen mode by code.
3. Add a StatusStrip.
4. Add a ToolStripDropDownButton with several dropdown items to the StatusStrip.
5. Run the application.
6. Click the drop-down button.

Tested app:
WinFormsApp167.zip

[Olina-Zhang]

Hi @KlausLoeffelmann, tested the fix in .NET 11/Integration-3: #14768:

• With KioskModeManager.HideTaskbar = false (the default), the StatusStrip ToolStripDropDown is positioned correctly.

• With KioskModeManager.HideTaskbar = true, the issue reproduces consistently—the drop-down is detached from its associated ToolStripItem and appears in an incorrect position.

So the issue seems to be specifically triggered when HideTaskbar is enabled.