ASP.NET in a Nutshell

Name

IPostBackDataHandler

Synopsis

This interface, which is implemented by many ASP.NET Server Controls, allows a control to receive and process postback data. It consists of two methods. The first, LoadPostData(), allows a control to receive the form data and update its properties as required. ASP.NET calls this method automatically on postback. It provides form data as a collection in the postCollection argument and a postDataKey argument identifying the control’s key (i.e., postCollection(postDataKey) will contain the posted information for the control). The control returns True from this method to indicate that its state has changed, or False if it hasn’t. ASP.NET calls the second method, RaisePostDataChangedEvent(), automatically after LoadPostData() if the control’s state is changed. The control can use this method to raise any required events. Events should never be raised from the LoadPostData() method because other controls may not have loaded their state information yet.

Public Interface IPostBackDataHandler
                  ' Public Instance Methods
   Public Function LoadPostData(ByVal postDataKey As String, 
        ByVal postCollection As System.Collections.Specialized.NameValueCollection) As Boolean  
   Public Sub RaisePostDataChangedEvent() 
End Interface