[Dark Mode] Different Icon Display for Expanding Nodes with Child Items in TreeView

[Syareel-Sukeri]

.NET version

9.0.0-rc.1.24414.1 + build private dll from winforms repo main branch

Did it work in .NET Framework?

No

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

This is a new feature Dark Mode: #11857

Issue description

The icon for expanding nodes with child items in TreeView appears differently in Dark Mode compared to Classic. Please confirm if this is the expected behavior. Below are the results in Classic and Dark Mode

Classic

Dark Mode

Steps to reproduce

1. Create a WinForms .NET Core application with TreeView control.
2. Populate the TreeView with a parent node that contains several child nodes.
3. Enable DarkMode by Application.SetColorMode(SystemColorMode.Dark) in Program.cs file.
4. Run the application.
5. Observe the expand icon

[dotnet-policy-service]

This issue is now marked as "help wanted", and we’re looking for a community volunteer to work on this issue. If we receive no interest in 180 days, we will close the issue. To learn more about how we handle feature requests, please see our documentation.

Happy Coding!