AppendHeader Method

HttpResponse.AppendHeader Method

Adds an HTTP header to the output stream.

[Visual Basic]
Public Sub AppendHeader( _
   ByVal name As String, _
   ByVal value As String _
public void AppendHeader(
 string name,
 string value
public: void AppendHeader(
 String* name,
 String* value
public function AppendHeader(
   name : String,
 value : String


The name of the HTTP header to add to the output stream.
The string to append to the header.


Exception Type Condition
HttpException The header is appended after the HTTP headers have been sent.


If you use the AppendHeader method to send cache-specific headers and at the same time use the cache object model (Cache) to set cache policy, HTTP response headers pertaining 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 sets the more restrictive header " Cache-Control: Private " via calls to SetCacheability, then the " Cache-Control: Private " header will be sent with the response.


Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family

See Also

HttpResponse Class | HttpResponse Members | System.Web Namespace

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