HttpResponse.AddCacheDependency(CacheDependency[]) 方法
定义
重要
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将一组缓存依赖项与响应关联,这样,如果响应存储在输出缓存中并且指定的依赖项发生变化,就可以使该响应失效。
public:
void AddCacheDependency(... cli::array <System::Web::Caching::CacheDependency ^> ^ dependencies);
public void AddCacheDependency (params System.Web.Caching.CacheDependency[] dependencies);
member this.AddCacheDependency : System.Web.Caching.CacheDependency[] -> unit
Public Sub AddCacheDependency (ParamArray dependencies As CacheDependency())
参数
- dependencies
- CacheDependency[]
要添加到应用程序依赖项列表的文件、缓存键或 CacheDependency。
例外
dependencies
参数为 null
。
在缓存处理管线中调用此方法太迟,已经在创建了缓存响应之后。
示例
以下示例演示如何使用 AddCacheDependency 方法和 CacheDependency 对象创建缓存依赖项。
<%@ Page Language="C#" %>
<%@ outputcache duration="30" varybyparam="none" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="Server">
private void Page_Load(object sender, System.EventArgs e)
{
// Create a Cache Dependency
// using a CacheDependency object.
CacheDependency authorsDependency = new CacheDependency("authors.xml");
// Make the page invalid if either of the
// cached items change or expire.
Response.AddCacheDependency(authorsDependency);
// Display the current time for cache reference
lblOutputCacheMsg.Text = DateTime.Now.ToString();
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Cache Dependencies</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<table>
<tbody>
<tr>
<td style="WIDTH: 118px">
The page was generated at:</td>
<td>
<asp:Label id="lblOutputCacheMsg" runat="server"></asp:Label>
</td>
</tr>
</tbody>
</table>
</form>
</body>
</html>
<%@ Page Language="VB" %>
<%@ outputcache duration="30" varybyparam="none" %>
<!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()
' Create a Cache Dependency
' using a CacheDependency object.
Dim authorsDependency("authors.xml") As CacheDependency
' Make the page invalid if either of the
' cached items change or expire.
Response.AddCacheDependency(authorsDependency)
' Display the current time for cache reference
lblOutputCacheMsg.Text = DateTime.Now.ToString()
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Cache Dependencies</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<table>
<tbody>
<tr>
<td style="WIDTH: 118px">
The page was generated at:</td>
<td>
<asp:Label id="lblOutputCacheMsg" runat="server"></asp:Label>
</td>
</tr>
</tbody>
</table>
</form>
</body>
</html>
注解
方法 AddCacheDependency 允许在缓存的响应和 CacheDependency 对象之间创建依赖项。