title: SourceName with MultiTriggers
body: <p>Is it possible to use a <code>MultiTrigger</code> to evaluate properties on multiple elements?  That don't reside within a template, but are within the Usercontrol/Window.</p>
  
  <p>Example:</p>
  
  <pre><code>&lt;CheckBox x:Name="checkBox1" /&gt;
  &lt;CheckBox x:Name="checkBox2" /&gt;
  
  &lt;CustomControl&gt;
     &lt;CustomControl.ContentTemplate&gt;
                &lt;DataTemplate&gt;
                          &lt;DataTemplate.Triggers&gt;
                              &lt;MultiTrigger&gt;
                                  &lt;MultiTrigger.Conditions&gt;
                                      &lt;Condition
                                          SourceName="checkBox1"
                                          Property="IsChecked"
                                          Value="False" /&gt;
                                      &lt;Condition
                                          SourceName="checkBox2"
                                          Property="IsChecked"
                                          Value="True" /&gt;
                                  &lt;/MultiTrigger.Conditions&gt;
                                  &lt;MultiTrigger.Setters&gt;
                                      &lt;Setter
                                          Property="Visibility"
                                          Value="Collapsed" /&gt;
                                  &lt;/MultiTrigger.Setters&gt;
                              &lt;/MultiTrigger&gt;
                          &lt;/DataTemplate.Triggers&gt;
                      &lt;/DataTemplate&gt;
  &lt;/CustomControl.ContentTemplate&gt;
  </code></pre>
  
  <p></p>
  
  <p>In a normal <code>Trigger</code> we can use the sourceName to trigger against properties on either of those checkbox controls, but with a <code>MultiTrigger</code> I get build errors when it attempts to find those controls.  </p>
  
  <p>Note:  The reason I'm using a <code>DataTemplate</code> as opposed to a <code>Style</code> is mentioned <a href="http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/b59822de-21ea-4a74-a115-3860241ba6b1" rel="nofollow noreferrer">here</a></p>