What for System.Web.Extensions ?

Question

By default ASP.NET 3.5 Web App project has references to assemblies System.Data.DataSetExtensions.dll and System.Web.Extensions.dll.

With System.Data.DataSetExtensions everything is clear for me, it contains such useful extension methods as DataTable.AsEnumerable() and DataTable.CopyToDataTable().

And what about System.Web.Extensions.dll? What useful members could you mention to use?

Answer 1

System.Web.Extensions.dll contains all the ASP.NET Ajax goodness such as the UpdatePanel control.

Answer 2

System.Web.Extensions contains all the classes and support classes for ASP.NET AJAX controls. It also includes the classes for JSON serialization and pretty much anything else that involves communication with the ASP.NET runtime from JavaScript (and vice versa).

Answer 3

From this page

The system.web.extensions element enables you to configure ASP.NET applications that can be used by AJAX-enabled clients, Windows Communication Foundation (WCF) clients (SOAP clients), and .NET Framework clients. The configuration settings include the following:

1. Enabling ASP.NET application services through the authenticationService, roleService, and profileService elements.
2. Configuring the script handler through the enableCompression and enableCaching attributes of the scriptResourceHandler element.
3. Configuring JSON serialization through the jsonSerialization element.

Answer 4

System.Web.Extensions is not about extension methods like System.Data.DataSetExtensions, it contains the ASP.NET AJAX Framework.