title: What is the WPF XAML Data Binding equivalent of String.Format?
body: <p>Or, to be more clear, how can I format a block of text (in my case, to be included within a tooltip) such that some portions of the text come from bound values.</p>
  
  <p>In plain C# I would use:</p>
  
  <pre><code>_toolTip.Text = string.Format("{1:#0}% up, {2:#0}% down",
      Environment.NewLine, percentageOne, percentage2);
  </code></pre>
  
  <p>However the WPF XAML markup for a Text property seems able to contain only a single binding.  The curly braces gave me high hopes, but this isn't possible:</p>
  
  <pre><code>&lt;Element&gt;
    &lt;Element.Tooltip&gt;
      &lt;!-- This won't compile --&gt;
      &lt;TextBlock Text="{Binding Path=PercentageOne}% up, {Binding Path=PercentageTwo}% down"/&gt;
    &lt;/Element.Tooltip&gt;
  &lt;/Element&gt;
  </code></pre>
  
  <p>I read that the <code>Run.Text</code> property is not a dependency property and can therefore not be bound.</p>
  
  <p>Is there a way I can perform this formatting in XAML?</p>