Assembly: System.Web (in system.web.dll)
public function GetVaryByCustomString ( context : HttpContext, custom : String ) : String
An HttpContext that contains information about the current Web request.
The custom string that specifies which cached response is used to respond to the current request.
Return ValueIf the value of custom is "browser", the browser's Type; otherwise, a null reference (Nothing in Visual Basic).
You can override GetVaryByCustomString to add a new method for calculating custom vary-by values based on the current request. The implementation has to call the base class for custom values that it does not recognize. For more information, see How to: Cache Versions of a Page Using Custom Strings.
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.