title: Xaml binding for conditional count
body: <p>I am creating a basic XX/YY control for an application, the total count is easy enough however I am having problems counting the XX which is based on a condition... </p>
  
  <pre><code>&lt;StackPanel Orientation="Horizontal" Height="55"  Width="130" HorizontalAlignment="Center" VerticalAlignment="Center"&gt;
          &lt;TextBlock Text="00" FontSize="40" Margin="5,0,5,5" /&gt;
          &lt;TextBlock Text="/" FontSize="40" Margin="5,0,5,5"/&gt;
          &lt;TextBlock Text="{Binding ItemList.Count, StringFormat={}{0:00}}" FontSize="40" Margin="5,0,5,5"/&gt;
      &lt;/StackPanel&gt;
  </code></pre>
  
  <p>the first textBlock should be Total count of ItemList where propertyX = 1</p>
  
  <p>any ideas how I can set up the above binding for the first textblock.</p>