6.5. Web Control Events and AutoPostBack
The previous chapter explained that one of the main limitations of HTML server controls is their limited set of useful events—they have exactly two. HTML controls that trigger a postback, such as buttons, raise a ServerClick event. Input controls provide a ServerChange event that doesn't actually fire until the page is posted back.
Server controls are really an ingenious illusion. You'll recall that the code in an ASP.NET page is processed on the server. It's then sent to the user as ordinary HTML. Figure 6-11 illustrates the order of events in page processing.
This is the same in ASP.NET as it was in traditional ASP programming. The question is, how can you write server code that will react immediately ...