Unfortunately, most examples of Ext JS are illustrated with PHP, Python and Ruby on Rails code on the server side. But that doesn’t mean developers using Microsoft technologies can’t take advantage of Ext JS. While it’s difficult to integrate Ext JS with Web Forms development (due to the abstraction layer that encapsulates the request-response nature of the Web in order to provide a stateful control-based model), you could use the ASP.NET MVC framework, enabling you to leverage both the Microsoft .NET Framework and Ext JS in the same app.
In this article, I’ll provide the tutorial I couldn’t find, walking through the development of a real-world Web solution using ASP.NET MVC and Ext JS that reads from and writes to a back-end database.
http://msdn.microsoft.com/en-us/magazine/gg650660.aspx
