NET AJAX Extensions is the ability to do a partial or incremental page updates without doing a full postback to the server, with no code changes and minimal markup changes.
The advantages are extensive – the state of your multimedia (such as Adobe Flash or Windows Media) is unchanged, bandwidth costs are reduced, and the client does not experience the flicker usually associated with a postback. NET technology brings an object-oriented and event-driven programming model and unites it with the benefits of compiled code.
AJAX posts all of the fields within the Update Panel, as captured by Fire Bug (see the diagram on the right).
As the screen capture indicates, values from every control within the Update Panel are delivered (in this case, they are all empty), as well as the View State field.
This means that the Update Panel can work with the default data-bound controls (such as the Grid View), with user controls, and they can be programmed in script.
By default, when a partial page render is triggered, all Update Panel controls on the page will be refreshed, whether or not the Update Panel controls defined triggers for such action.
The ability to integrate partial page rendering is integrated into ASP. When you launch your website, you should see that partial rendering is now enabled, because when you click on the button there will be no flicker, nor will there be any change in the page scroll position (this example does not demonstrate that).
Markup-Enabled Properties: Quite simply, the above script registers a callback with the client-side AJAX runtime for when the asynchronous request has been completed.
Visual Studio 2008 does not appear to come with a pre-defined template for an ASP. However, such a template was available within Visual Studio 2005 if the Visual Studio 2005 and ASP. Consequently, configuring a web site and starting with the AJAX-Enabled Web Site template will likely be even easier, as the template should include a fully-configured web.config file (supporting all of the ASP.
NET AJAX Extensions, including Web Services access and JSON serialization - Java Script Object Notation) and includes an Update Panel and Content Template within the main Web Forms page by default.
There are many design considerations to take into account, based on the requirements of a specific project.
(Click to view full-size image) (Click to view full-size image) In the original iteration of this application, a control was built that incorporated the entirety of the user registration data, including the postal code, city, and state.
To understand how the Update Panel works, so that you can best decide when its use is appropriate, you should examine the AJAX exchange.