Beginning ASP.NET 4.5.1: in C# and VB

Chapter 10ASP.NET AJAX

WHAT YOU WILL LEARN IN THIS CHAPTER:

• Using the UpdatePanel control to avoid page flicker
• Understanding the ScriptManager control that enables the Ajax functionality
• Using the UpdateProgress control to notify users about progress of an Ajax operation
• Creating WCF services that are accessible by your client-side script

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

You can find the wrox.com code downloads for this chapter on the Download Code tab at www.wrox.com/go/begaspnet451. The code is in the Chapter 10 folder.

Over the past few years, Ajax has popularized itself immensely in the web development community. Although the technology that drives Ajax has been around for quite some time, it wasn’t until the beginning of 2005 that it got an official name. Ajax, which stands for Asynchronous JavaScript And XML, enables your client-side web pages to exchange data with the server through asynchronous calls, which means they don’t block the user interface while running. Probably the most popular feature driven by Ajax is the flicker-free page that enables you to perform a postback to the server without refreshing the entire page. Note that the term Ajax doesn’t really cover the underlying technology anymore. Asynchronous JavaScript is still used to make the calls, but in many situations XML as the data format has been replaced with JSON (JavaScript Object Notation), as you see later in this chapter.

To enhance your website with Ajax features you can choose among ...