title: ComboBox cannot be opened after appying style
body: <p>I used XamlPadX to copy the defaultstyle of the ComboBox and pasted it into my app ressources.</p>
  
  <p>Now after that I cannot open the combobox anymore. If I click on the dropdown button, nothing happens.</p>
  
  <p>Another thing is bugging me. Altough the app compiles and runs, the designer shows me an error:</p>
  
  <blockquote>
    <p>"Value 'Control.Template' cannot be assigned to property 'Property'. 'IFrameworkInputElement' type does not have a matching DependencyObjectType.". </p>
  </blockquote>
  
  <p>on the following line:</p>
  
  <pre><code>&lt;ComboBox Name="modifier" SelectedIndex="0" Style="{DynamicResource MyComboStyle}"&gt;
         &lt;ComboBoxItem&gt;1&lt;/ComboBoxItem&gt;
         &lt;ComboBoxItem&gt;2&lt;/ComboBoxItem&gt;
         &lt;ComboBoxItem&gt;3&lt;/ComboBoxItem&gt;
  &lt;/ComboBox&gt;
  </code></pre>
  
  <p>Because of this the designer doesn't show me the control, but it shows up properly when the app is run.</p>
  
  <p>But when I declare the ComboBox as its own control there is no designer error:</p>
  
  <pre><code>&lt;ComboBox x:Class="ModifierControl"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"    
      Style="{DynamicResource MyComboStyle}" &gt;
  &lt;/ComboBox&gt;
  </code></pre>
  
  <p>Then no designer error is shown.</p>