title: Partial declarations must not specify different base classes?
body: <p>I see a number of other people asking about this error message in other questions, but I don't seem to understand enough about what's going on to fix this for myself. I created this error by having a WPF UserControl</p>
  
  <pre><code>public partial class EnterNewRequest : UserControl
  </code></pre>
  
  <p>But then later on I wanted to add a method to UserControl, so I used inheritance to stick it in there (can't use an extension because I need to override this method). But now my usercontrol is upset, and I'm not sure what in the xaml I need to change. The UserControl change block is in the namespace RCO_Manager. This is my xaml:</p>
  
  <pre><code>&lt;UserControl x:Class="RCO_Manager.EnterNewRequest"
           xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
           xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
           xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
           xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
  </code></pre>