HttpCapabilitiesBase.SupportsCacheControlMetaTag Property

 

Gets a value indicating whether the browser supports the cache-control value for the http-equiv attribute of HTML <meta> elements.

Namespace:   System.Web.Configuration
Assembly:  System.Web (in System.Web.dll)

public virtual bool SupportsCacheControlMetaTag { get; }

Property Value

Type: System.Boolean

true if the browser supports the cache-control value for the http-equiv attribute of HTML <meta> elements; otherwise, false. The default is true.

The cache-control value for the http-equiv attribute of HTML <meta> elements allows control over client caching of downloaded content, which includes Web pages. The following HTML fragment shows an example:

<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE"/>

If true, the inclusion of this tag in the <head> element of a Web page should force the browser to reload content from the server.

If false, server control adapters append a default query string (__ufps=uniquefilepathsuffix) onto link URL values that do not already have one. This forces the browser to reload content from the server.

The SupportsCacheControlMetaTag property also applies to the equivalent HTTP header form:

CACHE-CONTROL: NO-CACHE

The following code example shows how to determine whether the browser supports the cache-control value for the http-equiv attribute of HTML <meta> elements.

<%@ page language="C#"%>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    void Page_Load(Object Sender, EventArgs e)
    {
        CheckBrowserCaps();
    }

    void CheckBrowserCaps()
    {
        String labelText = "";
        System.Web.HttpBrowserCapabilities myBrowserCaps = Request.Browser;
        if (((System.Web.Configuration.HttpCapabilitiesBase)myBrowserCaps).SupportsCacheControlMetaTag)
        {
            labelText = "Browser supports the CACHE-CONTROL value for the HTTP-EQUIV attribute of HTML META elements.";
        }
        else
        {
            labelText = "Browser does not support the CACHE-CONTROL value for the HTTP-EQUIV attribute of HTML META elements.";
        }

        Label1.Text = labelText;
    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>Browser Capabilities Sample</title>
</head>
<body>
    <form runat="server" id="form1">
        <div>
            Browser Capabilities:
            <p/><asp:Label ID="Label1" Runat="server" />
        </div>
    </form>
</body>
</html>

.NET Framework
Available since 2.0
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