ControlCachePolicy.Duration 属性
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
获取或设置缓存的项将在输出缓存中保留的时间。
public:
property TimeSpan Duration { TimeSpan get(); void set(TimeSpan value); };public TimeSpan Duration { get; set; }member this.Duration : TimeSpan with get, setPublic Property Duration As TimeSpan属性值
TimeSpan，表示用户控件将在输出缓存中保留的时间。 默认值为 Zero。
例外
示例
下面的代码示例演示了如何在运行时以编程方式动态加载用户控件。 特性 PartialCachingAttribute 应用于名为 SimpleControl的用户控件，这意味着它在运行时由控件 PartialCachingControl 包装。 对象的 SimpleControl 缓存设置可以通过其关联的 ControlCachePolicy 对象以编程方式操作，该对象可通过对包装对象的控件的 PartialCachingControl 引用获得。 在此示例中，在 Duration 页面初始化期间检查 属性，如果满足某些条件，则更改缓存过期时间。 此示例是为 类提供的更大示例的 ControlCachePolicy 一部分。
<%@ Page Language="C#" %>
<%@ Reference Control="SimpleControl.ascx" %>
<script language="C#" runat="server">
// The following example demonstrates how to load a user control dynamically at run time, and
// work with the ControlCachePolicy object associated with it.
// Loads and displays a UserControl defined in a seperate Logonform.ascx file.
// You need to have "SimpleControl.ascx" file in
// the same directory as the aspx file.
void Page_Init(object sender, System.EventArgs e) {
// Obtain a PartialCachingControl object which wraps the 'LogOnControl' user control.
PartialCachingControl pcc = LoadControl("SimpleControl.ascx") as PartialCachingControl;
// If the control is slated to expire in greater than 60 Seconds
if (pcc.CachePolicy.Duration > TimeSpan.FromSeconds(60) )
{
// Make it expire faster. Set a new expiration time to 30 seconds, and make it
// an absolute expiration if it isnt already.
pcc.CachePolicy.SetExpires(DateTime.Now.Add(TimeSpan.FromSeconds(30)));
pcc.CachePolicy.SetSlidingExpiration(false);
}
Controls.Add(pcc);
}
</script>
<%@ Page Language="VB" %>
<%@ Reference Control="SimpleControl.ascx" %>
<script language="VB" runat="server">
' The following example demonstrates how to load a user control dynamically at run time, and
' work with the ControlCachePolicy object associated with it.
' Loads and displays a UserControl defined in a seperate Logonform.ascx file.
' You need to have "SimpleControl.ascx" file in
' the same directory as the aspx file.
Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs)
' Obtain a PartialCachingControl object which wraps the 'LogOnControl' user control.
Dim pcc As PartialCachingControl
pcc = LoadControl("SimpleControl.ascx")
' If the control is slated to expire in greater than 60 Seconds
If (pcc.CachePolicy.Duration > TimeSpan.FromSeconds(60)) Then
' Make it expire faster. Set a new expiration time to 30 seconds, and make it
' an absolute expiration if it isnt already.
pcc.CachePolicy.SetExpires(DateTime.Now.Add(TimeSpan.FromSeconds(30)))
pcc.CachePolicy.SetSlidingExpiration(False)
End If
Controls.Add(pcc)
End Sub
</script>
注解
如果使用 方法设置 SetSlidingExpiration 绝对过期策略，则 Duration 属性将返回缓存条目过期之前的剩余时间量。
