In addition to allowing you to reference script files
directly using a <script> element, ASP.NET 4.0 will make it easy to use
the CDN from ASP.NET Web Forms applications that use the
<asp:scriptmanager/> server control.
The ASP.NET 4.0 <asp:ScriptManager> control includes a
new property named EnableCdn. When you assign the value true to this property,
your application will use the Microsoft CDN to request JavaScript files
automatically:
When you enable the CDN with the ScriptManager, your
application will retrieve all JavaScript files that it normally retrieves from
the System.Web.dll or System.Web.Extensions.dll assemblies from the CDN
instead. This includes both the JavaScript files within ASP.NET AJAX, as
well as the built-in Web Forms JavaScript files (for example: the
WebUIValidation.js file for client-side validation, and the JavaScript files
for controls like TreeView, Menu, etc).
This provides a nice end-user performance improvement, and
means that users accessing your ASP.NET website won’t need to re-download these
files if they have visited another ASP.NET website that uses the CDN.
