This is a bug/misfeature in MenuStrip
.
Looking at the ToolStripDropDown.ProcessArrowKey
implementation with Reflector shows that the arrow keys get reversed depending on SystemInformation.RightAlignedMenus
. That's not right. It should depend on the right-to-left mode of the menu strip itself, which may sometimes (usually?) match SystemInformation.RightAlignedMenus
, but not always, and not on my system.
SystemInformation.RightAlignedMenus
is user-configurable via Control Panel, Tablet PC Settings, Other, Handedness, and indeed if I change that to Left-handed, I get the menus to behave correctly. The default and correct setting for me is Right-handed. Since the MenuStrip
component is simply not keyboard-usable on my system, I will replace my use of it with a standard MainMenu
component.
Update: I'm actually using a derived control to be able to provide nice menu images. It is based on the Microsoft sample on "Visual Style Menus". A more fully-featured implementation that also works on Windows XP and prior (in that case using owner-drawn menus) is available at Vista Menu with Icons in C#, but that is more complicated than necessary for me.