When this data member is enabled (which is the default), menu items that do not have ON_UPDATE_COMMAND_UI or ON_COMMAND handlers will be automatically disabled when the user pulls down a menu.
Menu items that have an ON_COMMAND handler but no ON_UPDATE_COMMAND_UI handler will be automatically enabled.
When this data member is set, menu items are automatically enabled in the same way that toolbar buttons are enabled.
m_bAutoMenuEnable has no effect on top-level menu items.
This data member simplifies the implementation of optional commands based on the current selection and reduces the need to write ON_UPDATE_COMMAND_UI handlers for enabling and disabling menu items.