Adds an HTTP header to the output stream.
Assembly: System.Web (in System.Web.dll)
The header is appended after the HTTP headers have been sent.
If you use the method to send cache-specific headers and at the same time use the cache object model (Cache) to set cache policy, HTTP response headers that pertain to caching (Cache-Control, Expires, Last-Modified, Pragma, and Vary) might be deleted when the cache object model is used. This behavior enables ASP.NET to maintain the most restrictive settings. For example, consider a page that includes user controls. If those controls have conflicting cache policies, the most restrictive cache policy will be used. If one user control sets the header "Cache-Control: Public" and another user control sets the more restrictive header "Cache-Control: Private" via calls to SetCacheability, then the "Cache-Control: Private" header will be sent with the response.
For a list of standard HTTP/1.1 headers, see section 14, "Header Field Definitions," in the Hypertext Transfer Protocol -- HTTP/1.1 specification on the World Wide Web Consortium (W3C) Web site.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.