Menus are used in menu bars and popup menus. A menu bar is a sequence of pull-down command menus near the top of the window, usually with a File menu as the first menu. In MS Windows and Motif, the menu bar is a standard user interface component. Under XView, wxWindows must simulate a menu bar with a series of menu buttons. Under wxWindows for Motif and MS Windows, but not XView, placing and ampersand before a letter in a menu name causes it to be underscored and interpreted as a keyboard shortcut. Under XView such underscores are ignored. The Motif version of wxWindows automatically right-justifies the help menu, if there is one.
Menu items are identified by integer identifiers, and for menu bars, when a menu item is selected, the parent frame is notified using the OnMenuCommand member. For popup menus, a callback function is executed.