Visual Basic® .NET by Example

The Event Model of a Web Form

The event model of an application using Web controls is different from the event model in a regular WinForms application. You have seen (in Figure 35.5) that in response to a client (usually browser) request, the .aspx page is rendered to an HTML document, which is then sent back in the HTTP response. The HTML page contains code (developed usually in a scripting language, such as JavaScript) that runs on the client, inside the browser. This code is generated when the page is rendered, and it is responsible to call back the server every time an event that requires a post-back is triggered.

Although this mechanism may seem innocuous (because it happens behind the scenes from what you have learned so far), it may have ...