Directive Syntax 

Specifies settings used by the page and user control compilers when they process ASP.NET Web Forms page (.aspx) and user control (.ascx) files.

Remarks

When used, directives can be located anywhere in an .aspx or .ascx file, though standard practice is to include them at the beginning of the file. Each directive can contain one or more attributes (paired with values) that are specific to that directive.

Note
The @ Page directive can be used only in .aspx files, and the @ Control directive can be used only in .ascx files.

The ASP.NET page framework supports the following directives.

@ Page	Defines page-specific attributes used by the ASP.NET page parser and compiler. Can be included only in .aspx files.
@ Control	Defines control-specific attributes used by the ASP.NET page parser and compiler. Can be included only in .ascx files (user controls).
@ Import	Explicitly imports a namespace into a page or user control.
@ Implements	Declaratively indicates that a page or user control implements a specified .NET Framework interface.
@ Register	Associates aliases with namespaces and class names, thereby allowing user controls and custom server controls to be rendered when included in a requested page or user control.
@ Assembly	Links an assembly to the current page during compilation, making all the assembly's classes and interfaces available for use on the page.
@ Master	Identifies an ASP.NET master page.
@ WebHandler	Identifies an ASP.NET IHttpHandler page.
@ PreviousPageType	Provides the means to get strong typing against the previous page as accessed through the PreviousPage property.
@ MasterType	Assigns a class name to the Master property of an ASP.NET page, so that the page can get strongly typed references to members of the master page.
@ OutputCache	Declaratively controls the output caching policies of a page or user control.
@ Reference	Declaratively links a page or user control to the current page or user control.

ASP.NET treats any directive block (<%@ %>) that does not contain an explicit directive name as an @ Page directive for a page, or an @ Control directive for a user control.

See Also

Reference

Page Class

Other Resources

ASP.NET Page Syntax