13.1. Caching Pages
Problem
You want to cache the pages in your application.
Solution
Add the @ OutputCache
directive to
the top of the
.aspx
file of each page you want to cache with
the VaryByParam
attribute set to
"none
“, as shown here:
<%@ Page Language="vb" AutoEventWireup="false"
Codebehind="CH13CachePageVB.aspx.vb"
Inherits="ASPNetCookbook.VBExamples.CH13CachePageVB" %>
<%@ OutputCache Duration="5" VaryByParam="none" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
...
</html>
Discussion
This recipe shows the minimum changes required to an
.aspx
file to cache a page of your ASP.NET
application. Only one @
OutputCache
directive can be included per page,
and the Duration
and
VaryByParam
attributes are required.
You specify how long the page is to be retained in the cache by
setting the Duration
attribute to the desired time
in seconds. In our example directive, the page will be rendered on
the first request for the page and placed in the cache. For five
seconds all subsequent requests for the page will be delivered from
the cached copy. After five seconds, the page will again be rendered.
The duration can be set to any positive integer value (1-2,147,483,647), which allows caching a page for approximately 68 years. You may be tempted to use very large numbers; however, every cached page uses server resources and if the page is not needed frequently, you will tie up server resources unnecessarily.
The VaryByParam
attribute is used to define parameters that determine ...
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