title: ASP: Extend control (ASCX) and access base markup file from subclass code
body: <p>I'm building form validation controls for our C# ASP application. The bulk of the work is handled by a BaseValidator control (subclassing System.Web.UI.UserControl), which also has the markup for the validation output. This is then extended by subcontrols like PasswordValidator, that provides the Validate method and any extra fields needed by that validator control.</p>
  
  <p>(The end goal is to have controls like &lt;uc1:PasswordValidator ControlId="txtPassword" /&gt; which we can plop into any form with minimum duplication.)</p>
  
  <p>However, PasswordValidator.ascx.cs cannot access the form elements defined in BaseValidator.ascx; the only way I've found to do so is to duplicate the markup in each subcontrol's *.ascx file. How can I extend BaseValidator.ascx.cs and access BaseValidator.ascx's markup in the subclass?</p>