Commandbar Actions
Commandbar actions eliminate the need to use the update notification\event to update\change the state and properties of an item that appears multiple places in your menus and toolbars. This also makes it easy to localize all the control with a single line of code.
In the diagram below, the "Menu Item," "Toolbar Item" and "User Customized Item (user created toolbar)" all share the same "Item Action." When you modify the properties of the action it will update all occurrences of the item.
