指定输出缓存的网页中不进行缓存的部分。在此位置，将检索动态内容，并用它们替代 Substitution 控件。
|
|---|
<asp:Substitution
????EnableTheming="True|False"
????EnableViewState="True|False"
????ID="string"
????MethodName="string"
????OnDataBinding="DataBinding event handler"
????OnDisposed="Disposed event handler"
????OnInit="Init event handler"
????OnLoad="Load event handler"
????OnPreRender="PreRender event handler"
????OnUnload="Unload event handler"
????runat="server"
????SkinID="string"
????Visible="True|False"
/> |
备注
示例
下面的代码示例演示如何以声明方式向输出缓存的网页添加一个 Substitution 控件。加载页时，在标签中向用户显示当前的日期和时间。每 60 秒缓存并更新页的此部分。当 Substitution 控件执行时，它调用 GetCurrentDateTime 方法。GetCurrentDateTime 返回的字符串显示给用户。页的此部分不进行缓存，而是在每次刷新页时进行更新。
| Visual Basic? |  复制代码 |
|---|
<%@ outputcache duration="60" varybyparam="none" %>
<script runat="server" language="VB">
Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
' Display the current date and time in the label.
' Output caching applies to this section of the page.
CachedDateLabel.Text = DateTime.Now.ToString()
End Sub
' The Substitution control calls this method to retrieve
' the current date and time. This section of the page
' is exempt from output caching.
Shared Function GetCurrentDateTime(ByVal context As HttpContext) As String
Return DateTime.Now.ToString()
End Function
</script>
<html>
<head id="Head1" runat="server">
<title>Substitution Class Example</title>
</head>
<body>
<form id="Form1" runat="server">
<h3>Substitution Class Example</h3>
<p>This section of the page is not cached:</p>
<asp:substitution id="Substitution1"
methodname="GetCurrentDateTime"
runat="Server">
</asp:substitution>
<br />
<p>This section of the page is cached:</p>
<asp:label id="CachedDateLabel"
runat="Server">
</asp:label>
<br /><br />
<asp:button id="RefreshButton"
text="Refresh Page"
runat="Server">
</asp:button>
</form>
</body>
</html>
|
| C#? | 复制代码 |
|---|
<%@ outputcache duration="60" varybyparam="none" %>
<script runat="server" language="C#">
void Page_Load(object sender, System.EventArgs e)
{
// Display the current date and time in the label.
// Output caching applies to this section of the page.
CachedDateLabel.Text = DateTime.Now.ToString();
}
// The Substitution control calls this method to retrieve
// the current date and time. This section of the page
// is exempt from output caching.
public static string GetCurrentDateTime (HttpContext context)
{
return DateTime.Now.ToString ();
}
</script>
<html>
<head runat="server">
<title>Substitution Class Example</title>
</head>
<body>
<form runat="server">
<h3>Substitution Class Example</h3>
<p>This section of the page is not cached:</p>
<asp:substitution id="Substitution1"
methodname="GetCurrentDateTime"
runat="Server">
</asp:substitution>
<br />
<p>This section of the page is cached:</p>
<asp:label id="CachedDateLabel"
runat="Server">
</asp:label>
<br /><br />
<asp:button id="RefreshButton"
text="Refresh Page"
runat="Server">
</asp:button>
</form>
</body>
</html>
|
请参见
参考
Substitution
概念
Substitution Web 服务器控件概述
