... into the Windows Forms architecture. Controls Are ClassesIn the .NET Framework, every control is a class. Windows controls are clustered in the System .Windows. Forms namespace. Web controls ... System.Web.UI, System.Web.UI.HtmlControls, and System.Web.UI.WebControls. (Web controls use a superficially similar but substantively different model than Windows controls, and they won’t be covered ... it interacts with the Windows Forms engine. The Windows Forms engine handles the Windows operating system messages that change focus or activate a window, and tells controls to paint themselves...