Chapter 7. The ASP.NET AJAX Toolkit

With the installation of the .NET Framework 3.5 and through using Visual Studio 2008, you will find a few controls available that allow you to build ASP.NET applications with AJAX capabilities. The .NET Framework 3.5 is the framework that takes your applications to the next level. There is so much that you can accomplish with this framework, including adding specific AJAX capabilities to your user and custom server controls. Every little tweak you make to your application in adding AJAX enhancements will make your application seem more fluid and responsive to the end user.

You might be wondering where the big new AJAX-enabled server controls are for this edition of Visual Studio 2008 if this is indeed a new world for building controls. The reason you do not see a new section of AJAX server controls is that Microsoft's work in this space has been treated as an open-source project instead of just blending it into Visual Studio 2008 as a whole.

Developers at Microsoft and in the community have been working on a series of AJAX-capable server controls that you can use in your ASP.NET applications. These controls are collectively called the ASP.NET AJAX Control Toolkit. If you go to www.asp.net/ajax, you will find a link to the Control Toolkit for downloading. When you choose to download the Control Toolkit, you are directed to the ASP.NET AJAX Control Toolkit's page on CodePlex at www.codeplex.com/Release/ProjectReleases.aspx?ReleaseId=16488. This page is presented in Figure 7-1.

As you have seen so far, ASP.NET AJAX is the foundation on which to build richer Web applications that leverage the browser more fully but it does not have the rich UI elements that really blur the distinction between Web and desktop applications. With the Microsoft AJAX Library, you can apply familiar object-oriented design concepts and use the scripts across a variety of modern browsers. The ASP.NET AJAX Extensions (a series of out-of-bound releases from the ASP.NET team to add extra functionality to the ASP.NET offering) include several powerful ASP.NET controls that make it easy to add AJAX functionality to an existing application or build better user experiences into a new application. The AJAX Toolkit was developed to provide some rich ASP.NET AJAX controls that you can use to make your Web applications really come to life. The Toolkit makes it easy to push the user interface of an application beyond what users expect from a Web application.

Figure 7-1. Figure 7-1

The Toolkit is a shared source project with code contributions from developers from Microsoft and elsewhere. Most developers who download the AJAX Extensions should also download the Toolkit for the additional set of controls it contains. The CodePlex project mentioned in this chapter allows you to download a compiled DLL with the controls and extenders, or you can download the source code and project files and compile it yourself. Either way, make sure that you add the DLL to your toolbox in Visual Studio, as described shortly.

The Toolkit contains some new controls that have AJAX functionality and many control extenders. The control extenders attach to another control to enhance or "extend" the control's functionality. When you install the Toolkit, it creates a sample Web application that includes examples that show how to use the controls. Because the controls cover such a wide variety of application-development areas, they are presented here in three categories: page layout controls, user interface effects, and pop-ups. Within each category, the controls are listed alphabetically; the control names are self-explanatory, so you will find it easy to locate the information you need when using this chapter for later reference.

Also, note that the Toolkit project is ongoing and will continue to evolve as developers contribute to it. This chapter is up to date as of the time of this writing, but I expect that more controls will be added to the Toolkit regularly.