Varying Output Caching by Browser

You can vary by browser the output cache for pages using two techniques; only the

@OutputCache

directive is supported for User Control caching:

<%@OutputCache Duration="60" VaryByParam="none"

VaryByCustom="browser" %>

[content]

or

<script runat="server">

' Note, this only works for pages and not user controls

Sub Page_Load(object As Sender, e As EventArgs)

Response.Cache.SetExpires(DateTime.Now.AddSeconds(100))

Response.Cache.SetCacheability(HttpCacheability.Public)

Response.Cache.SetValidUntilExpires(true)

Response.Cache.SetVaryByCustom("browser")

End Sub

</script>

[content]

Comments

ASP.NET server controls can render different content depending upon the user/agent

presented to the server during the request. All browsers present a user/agent that allows

the server addressing the request to know the capabilities of the browser.This is regardless

of whether the browsers are desktop browsers such as IE, Netscape, or Opera, or

mobile/device browsers, such as the browser found in a RIM device, cellular phone, or

handhelds.

Many ASP.NET server controls can render different content that is better suited to

the browser type making the request. A great example of this capability is existence of IE

Web Controls and ASP.NET Mobile controls (both available at www.asp.net).These

controls intelligently detect the browser type.When desktop browsers are used, HTML is

rendered.When mobile browsers are used,WML is rendered.

Varying the cache by browser allows for the ASP.NET cache to store different versions

of the requested page in the cache based on the type of browser making the

request.The only caveat is that only the browser type and major version number-IE

6.0, for example-are tracked. For example, versions 4.0, 4.1, and 4.5, of Netscape

browsers would all resolve to one entry within the cache.