Occurs when the System.Web.UI.WebControls.ImageButton is clicked.
The ImageButton.Command event is raised when an System.Web.UI.WebControls.ImageButton control is clicked.
The ImageButton.Command event is raised through the control hierarchy in the form of the BubbleEvent.
This event causes the page to post back to the server.
For more information about handling events, see How to: Consume Events in a Web Forms Application.