title: Expand the combobox and its items when it gets focus
body: <p>I want to expand the height of the combobox whenever the combobox gets the Focus.</p>
  
  <p>I have used the following code to expand the combobox height.</p>
  
  <pre><code>&lt;Style TargetType="{x:Type ComboBox}"&gt;    
  &lt;Style.Triggers&gt;    
      &lt;Trigger Property="IsKeyboardFocusWithin" Value="True"&gt;    
          &lt;Setter Property="RenderTransform"&gt;   
              &lt;Setter.Value&gt;   
                  &lt;ScaleTransform ScaleX="1" ScaleY="2" /&gt;   
              &lt;/Setter.Value&gt;   
          &lt;/Setter&gt;   
          &lt;Setter Property="RenderTransformOrigin" Value="0.5,0.5"/&gt;    
          &lt;Setter Property="Panel.ZIndex" Value="99999"/&gt;    
      &lt;/Trigger&gt;    
  &lt;/Style.Triggers&gt;  
  &lt;/Style&gt;
  </code></pre>
  
  <p>Problem:</p>
  
  <p>When i put the focus on the Combobox first time, the combobox item list opened in normal mode. But if i again click on the combobox then combobx item list opened and also list items height is expanded.</p>
  
  <p>But i want the combobox list items to be expanded even in the first click (focus) also. Also combobox height must be in expanded mode even when i select the item in the Combobox item.</p>
  
  <p>Thanks in advance</p>