How to simulate multiple inheritance for ASP.NET base pages?
<p>My project has been using a base page to hold common page functionality.  Its worked until the base page grew to be huge, so I tried to factor the base page into several classes.  Then I realized that I can't write </p>

<pre><code>public MyPage : SecurePage, PageWithGridViewSorting, PageWithSessionWarning
</code></pre>

<p>given something like:</p>

<pre><code>public class SecurePage : RadAjaxPage
{
    // Add session id to ViewStateUserKey
}

public class PageWithGridViewSorting : RadAjaxPage
{
    // add sorting to all grids on page
}

public class PageWithSessionWarning : RadAjaxPage
{
    // inject javascript to warn user of impending session end
}
</code></pre>

<p>Which way am I supposed to take this?  And I think the fact that this is the ASP.NET page is relevant because it is a class that gets constructed by the framework, not me. My first thought was to make a override for the constructor and pass in the features and that wont work with System.Web.UI.Page.</p>
