CCmdUI does not have a base class.
The CCmdUI class is used only within an ON_UPDATE_COMMAND_UI handler in a CCmdTarget-derived class.
When a user of your application pulls down a menu, each menu item needs to know whether it should be displayed as enabled or disabled. The target of a menu command provides this information by implementing an ON_UPDATE_COMMAND_UI handler. Use ClassWizard to browse the command user-interface objects in your application and create a message-map entry and function prototype for each handler.
When the menu is pulled down, the framework searches for and calls each ON_UPDATE_COMMAND_UI handler, each handler calls CCmdUI member functions such as Enable and Check, and the framework then appropriately displays each menu item.
A menu item can be replaced with a control-bar button or other command user-interface object without changing the code within the ON_UPDATE_COMMAND_UI handler.
The following table summarizes the effect CCmdUI’s member functions have on various command user-interface items.
| User-Interface Item | Enable | SetCheck | SetRadio | SetText |
| Menu item | Enables or disables | Checks (×) or unchecks | Checks using dot () | Sets item text |
| Toolbar button | Enables or disables | Selects, unselects, or indeterminate | Same as SetCheck | (Not applicable) |
| Status-bar pane | Makes text visible or invisible | Sets pop-out or normal border | Same as SetCheck | Sets pane text |
| Normal button in CDialogBar | Enables or disables | Checks or unchecks check box | Same as SetCheck | Sets button text |
| Normal control in CDialogBar | Enables or disables | (Not applicable) | (Not applicable) | Sets window text |
For more on the use of this class, see Constructing the User Interface in Visual C++ Tutorials and How to Update User-Interface Objects in Visual C++ Programmer's Guide.
#include <afxwin.h>
Class Members | Hierarchy Chart
Sample MFC Sample MDI
See Also CCmdTarget