HttpCachePolicy.AppendCacheExtension(String) Method

Definition

Namespace:

System.Web

Assembly:

System.Web.dll

Appends the specified text to the Cache-Control HTTP header.

public:
 void AppendCacheExtension(System::String ^ extension);

public void AppendCacheExtension (string extension);

member this.AppendCacheExtension : string -> unit

Public Sub AppendCacheExtension (extension As String)

Parameters

extension

String

The text to append to the Cache-Control header.

Exceptions

ArgumentNullException

extension is null.

Examples

The following code example demonstrates the use of a cache-control extension supported by Internet Explorer. The server is indicating to the browser that the content will not change for one hour (pre-check=3600) and instructs it to retrieve the content directly from the local cache. However, if the content is modified by the server and the page is requested by the user within a fifteen-minute (post-check= 900) to one-hour period, the browser displays the information found in the local cache but also performs a background check and optional fetch of the new content on the server.

Response.Cache.AppendCacheExtension("post-check=900,pre-check=3600");

Response.Cache.AppendCacheExtension("post-check=900,pre-check=3600")

Remarks

If the browser does not recognize cache control directives or extensions, the browser must ignore the unrecognized terms. For more information, see RFC 2616: Hypertext Transfer Protocol -- HTTP/1.1, available on the World Wide Web Consortium (W3C) Web site.

AppendCacheExtension is introduced in the .NET Framework version 3.5. For more information, see Versions and Dependencies.