HttpResponse.AddCacheDependency Method
Associates a set of cache dependencies with the response to facilitate invalidation of the response if it is stored in the output cache and the specified dependencies change.
Namespace: System.Web
Assembly: System.Web (in System.Web.dll)
Parameters
- dependencies
- Type: System.Web.Caching.CacheDependency[]
A file, cache key, or CacheDependency to add to the list of application dependencies.
| Exception | Condition |
|---|---|
| ArgumentNullException | The dependencies parameter is null. |
| InvalidOperationException | This method was called too late in the cache processing pipeline, after the cached response was already created. |
The AddCacheDependency method allows dependencies to be created between cached responses and a CacheDependency object.
The following example demonstrates how to create a cache dependency by using the AddCacheDependency method and a CacheDependency object.
<%@ Page Language="C#" %> <%@ outputcache duration="30" varybyparam="none" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="Server"> private void Page_Load(object sender, System.EventArgs e) { // Create a Cache Dependency // using a CacheDependency object. CacheDependency authorsDependency = new CacheDependency("authors.xml"); // Make the page invalid if either of the // cached items change or expire. Response.AddCacheDependency(authorsDependency); // Display the current time for cache reference lblOutputCacheMsg.Text = DateTime.Now.ToString(); } </script> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <title>Cache Dependencies</title> </head> <body> <form id="Form1" method="post" runat="server"> <table> <tbody> <tr> <td style="WIDTH: 118px"> The page was generated at:</td> <td> <asp:Label id="lblOutputCacheMsg" runat="server"></asp:Label> </td> </tr> </tbody> </table> </form> </body> </html>
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
