Instead, we call
the DataBind() method on the Page_Load handler itself. The DataBind() method of the Page class
recursively calls the DataBind() methods for all its child controls that have references to a data
source. In this case, when the Page class??™s DataBind() method is invoked, the DropDownList
control data binds to the ArrayList object as shown previously.
Control Events
Events are the final constructs used for interacting with controls that we discuss in this chapter.
Events provide a mechanism to notify clients of state changes inside the control. In ASP.NET,
events always coincide with an HTTP POST submission back to the web server. Through the
automatic postback mechanism, events in ASP.NET appear to behave very much like their
counterparts in a Windows Forms application.
?– Note Events provide an object-oriented mechanism for a control to communicate with other controls that
care to know about state changes within that control. If events did not exist, objects would have to resort to
polling to know about state changes in other objects. The asynchronous nature of events provides an elegant
means for communicating between objects. Event handler methods are generally protected to the control
class (the event subscriber), as it would not make sense to call event handlers outside the consuming class.
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