"Pro ASP.NET 3.5 Server Controls and AJAX Components"
RaisePostDataChangedEvent() is blank, because we are not emitting events from our control based on state changes, but it still must be present to satisfy the terms of the interface. In the next chapter, we go further into raising our own events and examine what kind of code you would normally put into the RaisePostDataChangedEvent(). LoadPostData() has the necessary logic to read the information posted by our type="text"> tag rendered in the HTML document. LoadPostData() uses the passed-in key to read from the postCollection collection passed into the routine. The type of the collection is NameValueCollection, so you can expect a string value to be passed back when you access the data with your key. Once we pull out the data, we store it immediately in ViewState via the Text property so the control can remember what was sent to it as well as render the correct HTML for the tag with the value filled in upon return to the browser. The LoadPostData() routine closes by returning false, because it does not need to have RaisePostDataChangedEvent() called, as no events are implemented. Using the Textbox Control The Postback Data web form is identical to the previous Label Controls demonstration except for removal of the ASP.