Summary

In this chapter, you have seen how you can use ASP.NET AJAX to enhance ASP.NET Web applications. ASP.NET AJAX contains a wealth of functionality that makes Web application far more responsive and dynamic and can provide a much better user experience.

To begin with, you learned what Ajax is, and about the separate components of ASP.NET AJAX that are available and what they offer. You saw the difference between AJAX Extensions and the AJAX Library and how these components work together to provide the core ASP.NET AJAX functionality. You also looked at the AJAX Control Toolkit and ASP.NET 2.0 AJAX Futures CTP, which add to this core functionality.

Next, you moved on to look as server-side techniques for creating ASP.NET AJAX-enabled Web applications. You saw how to configure ASP.NET AJAX in the Web.config file of your ASP.NET Web applications and how to use the various server controls that are part of the AJAX Extensions. Specifically, you learned about ScriptManager, UpdatePanel (and triggers), UpdateProgress, and extender controls. You saw how easy it is to use these controls to add a great deal of functionality to a Web application very quickly.

After looking at the server-side components, you moved on to examine the AJAX Library. The AJAX Library extends and enhances JavaScript and provides you with a great deal of additional functionality that you can add to applications - but does require at least a working knowledge of JavaScript programming.

You learned about the global functions that the AJAX Library adds to JavaScript and how to define namespaces and classes by using the OOP extensions to JavaScript that the AJAX Library adds. After that, you moved on to see how to interact with events that occur on the client during the life cycle of a page and partial-page postbacks. You saw how to use one of these events, PageRequestManager.endRequest, to customize how server errors that occur during a partial page postback are displayed in the Web browser.

Finally, you looked at client-side Web method calls. You saw how an asynchronous model is used for these and how to write the required code to call a simple Web method. You also learned about accessing the ASP.NET application services (authorization, profile, and membership) through Web services.

Hopefully, this chapter has given you an appetite for this exciting new technology. Ajax is blossoming across the Web, and ASP.NET AJAX is an excellent way to integrate Ajax functionality with ASP.NET applications. This product is also very well supported, and the community-based releases such as the AJAX Control Toolkit provide you with even more great functionality that you are free to use in your applications.

Even though you may find yourself having to learn that JavaScript language you never thought you’d need, the end result is well worth the effort. By using ASP.NET AJAX you will make far better, more functional, and more dynamic Web applications than you could with ASP.NET alone. And, as you have seen, at some point ASP.NET AJAX will cease to be separate from ASP.NET, so you should learn how to use it as soon as you can.