I wrote in a past article about unit testing ASP.NET pages. It is also possible to work with user controls, with some additional considerations.  User controls inherit from System.Web.UI.UserControl class; however, it is possible to create an intermediate class, between the UserControl class and the ASP.NET user control (.ascx). This can perform more advanced capabilities and allow the user control to be unit tested, at least partially.

In addition, by crafting an application in a certain way, it can be possible to perform more advanced testing, such as the testing of dynamic table generation within the user control, of data binding to a data-bound control, or other features.