ASP.NET Class Library 

.NET Framework 3.0

The Windows SDK class library includes a subset of namespaces that allow you to create ASP.NET Web sites, components, and controls. The following sections describe the key namespaces provided for ASP.NET development. To browse the entire Windows SDK class library, see Class Library.

ASP.NET Web Site Development

  • System.Web – contains classes and interfaces that enable browser/server communication. This namespace provides classes for managing HTTP output to the client (HttpResponse) and reading HTTP requests (HttpRequest). Additional classes provide facilities for server-side utilities and processes, cookie manipulation, file transfer, exception information, and output cache control.

  • System.Web.UI – contains classes for creating Web Form pages, including the Page class and other standard classes used to create Web user interfaces.

  • System.Web.UI.HtmlControls – contains classes for HTML-specific controls that can be added to Web Forms to create Web user interfaces.

  • System.Web.UI.WebControls – contains classes for creating ASP.NET Web server controls. When added to a Web Form, these controls render browser-specific HTML and script to create a device-independent Web user interface.

  • System.Web.UI.WebControls.WebParts – contains an integrated set of classes and interfaces for creating Web pages whose appearance and behavior can be modified (personalized) by end users. The user-defined settings for each page are saved for future browser sessions.

Control and Component Development

  • System.ComponentModel – provides classes that are used to implement the run-time and design-time behavior of components and controls. This namespace includes the base classes and interfaces for implementing attributes, working with type converters, binding to data sources, and licensing components.

  • System.Web.UI.Design – contains classes that can be used to extend design-time support for Web Forms.

  • System.Web.UI.Design.WebControls – contains classes that can be used to extend design-time support for Web server controls.

  • System.Web.UI.Design.WebControls.WebParts – contains classes that provide design-time support for controls derived from classes in the System.Web.UI.WebControls.WebParts namespace.


  • System.Configuration – provides classes and interfaces that allow you to programmatically access .NET Framework configuration settings and handle errors in configuration files (.config files).

  • System.Web.Configuration – contains classes that are used to set up ASP.NET configuration.

Management and Hosting

  • System.Web.Administration – contains classes used by the Web Site Administration Tool to administer and configure ASP.NET applications on a Web server.

  • System.Web.Hosting – provides the functionality for hosting ASP.NET applications from managed applications outside of Microsoft Internet Information Services (IIS).

  • System.Web.Management – contains classes and interfaces for managing and monitoring the health of Web applications.

See Also

Community Additions