title: Partial declarations of must not specify different base classes
body: <p>I know there is information on this on the internet but Im having problems translating it to my situation. </p>
  
  <p>I have a xaml window and im getting the error: Partial declarations of 'GX3OpenStackupGUIPlugin.GX3OpenStackupGUIPlugin' must not specify different base classes
  .</p>
  
  <p>My code behind is:</p>
  
  <pre><code>public partial class GX3OpenStackupGUIPlugin : GX3ClientPlugin, IGX3PluginInterface
      {
  </code></pre>
  
  <p>My xaml is: </p>
  
  <pre><code>&lt;Grid xmlns:my="clr-namespace:CustomControls;assembly=MultiComboBox"   xmlns:extToolkit="http://schemas.microsoft.com/winfx/2006/xaml/presentation/toolkit/extended"   x:Class="GX3OpenStackupGUIPlugin.GX3OpenStackupGUIPlugin"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"&gt;
  </code></pre>
  
  <p>Please could someone advise :)</p>
  
  <p>Here is a link to what I have found but am struggling to translate...
  <a href="https://stackoverflow.com/questions/8800872/partial-declarations-must-not-specify-different-base-classes">Partial declarations must not specify different base classes</a></p>
  
  <p>After doing a little more research I have discovered that if I change my code behind to implement the top level element in my xaml it gets rid of the error. Thats obviously still a problem as my codebehind class needs to implement the interfaces I have designed. </p>