Windows 11 Context Menu Style

Question

Default styles offered for the Windows Forms context menu control (using ContextMenuStrip ) are looking like something that was created for Office XP - its styling doesn't quite match that of Windows 11.

For contrast, a modern Windows 11 context menu has rounded corners and is theme-aware:

Even for cases where it is not theme-aware for some legacy applications, it's still using rounded corners.

How can I replicate the theme-aware style and the modern (rounded corner) context menu for a Windows 11 tray icon from a Windows Forms (or Console) application?

Ideally, I am trying not to write a whole tray menu renderer from scratch and instead just re-use built-in OS components, but so far I am running into a wall when it comes to figuring out what tooling I need to use to even get the menu.

Answer 1

Use this class

class CustomContextMenu : ContextMenuStrip
{
    [DllImport("dwmapi.dll", CharSet = CharSet.Unicode, SetLastError = true)]
    private static extern long DwmSetWindowAttribute(IntPtr hwnd,
                                                        DWMWINDOWATTRIBUTE attribute,
                                                        ref DWM_WINDOW_CORNER_PREFERENCE pvAttribute,
                                                        uint cbAttribute);
    
    public CustomContextMenu()
    {
        var preference = DWM_WINDOW_CORNER_PREFERENCE.DWMWCP_ROUND;     //change as you want
        DwmSetWindowAttribute(Handle,
                              DWMWINDOWATTRIBUTE.DWMWA_WINDOW_CORNER_PREFERENCE,
                              ref preference,
                              sizeof(uint));
    }

    public enum DWMWINDOWATTRIBUTE
    {
        DWMWA_WINDOW_CORNER_PREFERENCE = 33
    }
    public enum DWM_WINDOW_CORNER_PREFERENCE
    {
        DWMWA_DEFAULT = 0,
        DWMWCP_DONOTROUND = 1,
        DWMWCP_ROUND = 2,
        DWMWCP_ROUNDSMALL = 3,
    }
}