ASP.NET 'Donut Caching' not working

Question

I have an ASP.NET page where I am trying to cache output but have encountered a problem. My ASPX page has

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="MYProject._Default" %>
<%@ OutputCache Duration="600" VaryByParam="None" %>
<%@ Register TagPrefix="MYProjectUC" TagName="PageHeader" Src="~/Lib/UserControls/PageHeader.ascx" %>
<%@ Register TagPrefix="MYProjectUC" TagName="PageFooter" Src="~/Lib/UserControls/PageFooter.ascx" %>

I have a user control called "PageHeader" on an ASPX page. In PageHeader.ascxI have an ASP.NET control Substitutionwhere I want to show some links based on a registered user.

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="PageHeader.ascx.cs" Inherits="MyProject.Lib.UserControls.PageHeader1" %>
<div class="headerRow">
    <div class="headerLogo">
        <a href="Default.aspx"><img src="Lib/Images/header.gif" alt=""></a>
    </div>
    <div id="divHeaderMenu" runat="server">         
        <asp:Substitution ID="subLinks" runat="server" MethodName="GetUserProfileHeaderLinks" />
    </div>   
</div><!--headerRow-->

In my user control code, I have a static method that will return a string based on whether the session login is used or not:

public static string GetUserProfileHeaderLinks(HttpContext context)
{
    string strHeaderLinks = string.Empty;
    // check session and return string
    return strHeaderLinks;
}

But the page still shows the same content for the user and the guest user.

My goal is to cache the page except for the content inside the replacement control. How to do it?

Answer 1

. . VaryByParams, VaryByHeaders.

http://msdn.microsoft.com/en-us/library/aa719665%28v=VS.71%29.aspx

Answer 2

, , , Substitution: . ( , .)

ASP.Net Substitution?, , , , ...