. asp.net AJAX in NET3.5 and VS2008

In the past, I have discussed the improvements in JavaScript and Ajax in VS 2008 JavaScript Intellisense and vs 2008 JavaScript debugging. Here are a few comments on some of the ASP.net Ajax Run-time features that are released as part of VS 2008 and. NET 3.5, and several important things to know when you open an existing ASP.net Ajax 1.0 project in VS 2008.

asp.net AJAX included in. NET 3.5

asp.net AJAX 1.0 is published in a single download that can be installed on ASP.net 2.0. Starting with. NET Framework 3.5, all of these features become ASP. NET, which means that you no longer need to download and install separate asp.net ajax installation files when building or deploying applications.

When you create a target in VS 2008. NET Framework 3.5 's new ASP.net application or Web site project, vs will automatically add the appropriate AJAX registration settings to your Web.config file, and the core asp.net Ajax server controls will appear in your toolbox.

There have been a number of improvements to the ASP.net AJAX version released with. NET 3.5-including support for UpdatePanel that can be used with WebPart, support for WCF-based JSON nodes, Support for using ASP.net user data, roles and login application services in JavaScript, and n bug fixes and performance improvements.

Understanding the version of ASP.net Ajax

asp.net AJAX 1.0 and. NET 3.5 can be installed in parallel on the same machine. ASP.net Ajax 1.0 is implemented in System.Web.Extensions.dll V1.0 assemblies, and ASP.net Ajax implementations included in. NET 3.5 exist in System.Web.Extensions.dll V3.5 assemblies. The V3.5 version of System.Web.Extensions.dll is a fully compatible extension set (which means you don't have to change any code to use it).

Each asp.net application on the machine can optionally be built and run using any of the ASP.net AJAX versions. This is configured by using a subset of the nodes in the Web.config file and the version of the System.Web.Extensions.dll assembly that is referenced at compile time (in the Web site project, these references are registered in the web.config files, and Web application projects specify these references through the project file.

You will be able to use VS 2008来 to develop applications for ASP.net Ajax 3.5 and to build a asp.net 2.0 application using asp.net Ajax 1.0 using the new VS 2008-directional support. In the following section, I will discuss how to do it.

Important Beta 2 Information

A few days before we published Beta2 on the web, we found a problem with installing ASP.net ajax in parallel. If you have read my blog post on the VS 2008 and. NET 3.5 Beta 2 release, you will remember the following installation patch step that I specifically pointed out to fix this problem:

You should download and run this batch of files. It takes only a few seconds to run, and it fixes the issue of the System.Web.Extensions.dll version policy that we found earlier this week, which contains ASP.net AJAX. If you do not run this batch of files, the existing ASP.net 2.0 project built with ASP.net AJAX 1.0 and VS 2005 will automatically carry the new ASP.net AJAX version released with the. NET 3.5 Beta2. This will work and run well, but will inadvertently cause your VS2005 application to depend on. NET 3.5. Running this batch of files changes the version binding policy of the new System.Web.Extensions.dll assembly, ensuring that you only use the new. NET 3.5 asp.net Ajax version when you explicitly build the. NET 3.5 project.

The good news is that this will fix the parallel installation problem we found, allowing us to safely develop ASP.net AJAX applications on the same machine using VS 2005 and VS 2008.