HttpCapabilitiesBase.SupportsCacheControlMetaTag 屬性

  • 參考

定義

命名空間:
System.Web.Configuration
組件:
System.Web.dll

取得值，指出瀏覽器是否支援 HTML cache-control 項目 http-equiv 屬性的 <meta> 值。

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

屬性值

Boolean

如果瀏覽器支援 HTML <meta> 項目之 http-equiv 屬性的 cache-control 值，則為 true；否則為 false。 預設為 true。

範例

下列程式碼範例示範如何判斷瀏覽器是否支援 cache-control HTML <meta> 元素屬性的值 http-equiv 。

<%@ 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>

備註

cache-controlHTML <meta> 元素屬性的值 http-equiv 允許控制下載內容的用戶端快取，包括網頁。 下列 HTML 片段顯示範例：

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

如果 true 為 ，則網頁元素中包含 <head> 此標籤應該強制瀏覽器從伺服器重載內容。

如果 false 為 ，伺服器控制項配接器會將預設查詢字串附加 () __ufps=``uniquefilepathsuffix 至還沒有連結 URL 值。 這會強制瀏覽器從伺服器重載內容。

屬性 SupportsCacheControlMetaTag 也適用于對等的 HTTP 標頭表單：

CACHE-CONTROL: NO-CACHE

適用於