This interface allows a control to raise events in response to a postback operation. This interface is commonly used for button controls like System.Web.UI.WebControls.Button and System.Web.UI.WebControls.ImageButton. It can be used instead of, or in conjunction with, the IPostBackDataHandler interface. The distinction is that the RaisePostBackEvent( ) method is always called when a postback event occurs. The IPostBackDataHandler.RaisePostDataChangedEvent( ) method is called only if the control's state has changed, and is thus more suited for a "Change" event than a "Click" event.
public interface IPostBackEventHandler { // Public Instance Methods public void RaisePostBackEvent(string eventArgument); }