title: Wpf ComboBox Trigger
body: <p>I have two ComboBoxes as follows</p>
  
  <pre><code>&lt;StackPanel Orientation="Horizontal" &gt;
  &lt;ComboBox x:Name="cbxOne"  Style="{StaticResource demoStyle}" &gt;
      &lt;ComboBoxItem &gt;One&lt;/ComboBoxItem&gt;
      &lt;ComboBoxItem &gt;Two&lt;/ComboBoxItem&gt;
      &lt;ComboBoxItem &gt;All&lt;/ComboBoxItem&gt;
  &lt;/ComboBox&gt;
  &lt;ComboBox x:Name="cbxTwo"&gt;
      &lt;ComboBoxItem &gt;1&lt;/ComboBoxItem&gt;
      &lt;ComboBoxItem &gt;2&lt;/ComboBoxItem&gt;
  &lt;/ComboBox&gt;
  &lt;/StackPanel&gt;
  </code></pre>
  
  <p>I tried this style</p>
  
  <pre><code>&lt;Style x:Key="demoStyle" TargetType="{x:Type ComboBox}"&gt;
      &lt;Style.Triggers&gt;
      &lt;Trigger Property="SelectedValue" Value="All"&gt;
                  &lt;Setter Property="cbxTwo.Visibility" Value="Collapsed"&gt;&lt;/Setter&gt;
          &lt;/Trigger&gt;
      &lt;/Style.Triggers&gt;
  &lt;/Style&gt;
  </code></pre>
  
  <p>I want when the first is 'All' to hide the second using Xaml and trigger.</p>
  
  <p>Thanks</p>