As per the subject, here's a simple sample
global.asax
<%@ Application Language="C#" %>
<script runat="server">
void Application_Start(object sender, EventArgs e)
{
HttpRuntime.Cache.Insert("myCacheKey", DateTime.Now);
}
</script>
Webusercontrol.ascx
<%@ Control Language="C#" ClassName="WebUserControl" %>
<%@ OutputCache VaryByParam="None" Duration="600" %>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
String[] dependencyKey = new String[1];
dependencyKey[0] = "myCacheKey";
BasePartialCachingControl pcc = Parent as BasePartialCachingControl;
if(pcc != null)
pcc.Dependency = new CacheDependency(null, dependencyKey);
}
</script>
FROM UC:<%=DateTime.Now.ToString()%>
Default.aspx
<%@ Page Language="C#" %>
<%@ Register Src="WebUserControl.ascx" TagName="WebUserControl" TagPrefix="uc1" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Button2_Click(object sender, EventArgs e)
{
Cache.Insert("myCacheKey", DateTime.Now);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<uc1:WebUserControl id="WebUserControl1" runat="server"></uc1:WebUserControl></div>
FROM PAGE:<%=DateTime.Now.ToString() %>
<asp:Button ID="Button1" runat="server" Text="Cause a postback" />
<asp:Button ID="Button2" runat="server" Text="Remove from cache" OnClick="Button2_Click" />
</form>
</body>
</html>
See also Steve Smith's article: Remove ASP.NET Page Output Cache Entries