HttpCapabilitiesBase.SupportsCacheControlMetaTag Propriedade

Definição

Obtém um valor que indica se o navegador dá suporte ao valor cache-control do atributo http-equiv de elementos HTML <meta>.Gets a value indicating whether the browser supports the cache-control value for the http-equiv attribute of HTML <meta> elements.

public:
 virtual property bool SupportsCacheControlMetaTag { bool get(); };
public virtual bool SupportsCacheControlMetaTag { get; }
member this.SupportsCacheControlMetaTag : bool
Public Overridable ReadOnly Property SupportsCacheControlMetaTag As Boolean

Valor da propriedade

Boolean

true Se o navegador oferecer suporte ao cache-control valor para o http-equiv atributo de <meta> elementos HTML; caso contrário, false .true if the browser supports the cache-control value for the http-equiv attribute of HTML <meta> elements; otherwise, false. O padrão é true.The default is true.

Exemplos

O exemplo de código a seguir mostra como determinar se o navegador oferece suporte ao cache-control valor para o http-equiv atributo de <meta> elementos HTML.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>
<%@ page language="VB" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
    Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
        CheckBrowserCaps()
    End Sub

    Function CheckBrowserCaps()

        Dim labelText As String = ""
        Dim myBrowserCaps As System.Web.HttpBrowserCapabilities = Request.Browser
        If (CType(myBrowserCaps, System.Web.Configuration.HttpCapabilitiesBase)).SupportsCacheControlMetaTag Then
            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."
        End If

        Label1.Text = labelText

    End Function 'CheckBrowserCaps
</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>

Comentários

O cache-control valor para o http-equiv atributo de <meta> elementos HTML permite o controle sobre o cache de conteúdo baixado do cliente, que inclui páginas da Web.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. O fragmento HTML a seguir mostra um exemplo:The following HTML fragment shows an example:

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

Se true , a inclusão dessa marca no <head> elemento de uma página da Web deve forçar o navegador a recarregar o conteúdo do servidor.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.

Se false , os adaptadores de controle de servidor anexarão uma cadeia de caracteres de consulta padrão ( __ufps=``uniquefilepathsuffix ) nos valores de URL de link que ainda não têm um.If false, server control adapters append a default query string (__ufps=``uniquefilepathsuffix) onto link URL values that do not already have one. Isso força o navegador a recarregar o conteúdo do servidor.This forces the browser to reload content from the server.

A SupportsCacheControlMetaTag propriedade também se aplica ao formato de cabeçalho http equivalente:The SupportsCacheControlMetaTag property also applies to the equivalent HTTP header form:

CACHE-CONTROL: NO-CACHE  

Aplica-se a