title: WPF Tag button binding with ConverterParameter
body: <p>I have a <code>Button</code> whose <code>Tag</code> depends on a boolean variable.
  I implemented the Binding as follow:</p>
  
  <pre><code>Tag="{Binding LiveInProgress, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type UserControl}}, 
        Converter={StaticResource BoolToPathConverter}, Mode=OneWay, 
        ConverterParameter=cross.svg|play.svg}"
  </code></pre>
  
  <p>Where the <code>Converter</code> is the following:</p>
  
  <pre><code>public class BoolToPathConverter : IValueConverter
      {
          public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
          {
              var parameterString = parameter as string;
              if (parameterString.IsNullOrEmpty()) return "";
  
              var parameters = parameterString.Split(new char[]{ '|'});
              if ((bool) value)
                  return parameters[0];
  
              return parameters[1];
          }
  
          public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
          {
              throw new NotImplementedException();
          }
      }
  </code></pre>
  
  <p>The problem is that I can't see any Tag. Do you have any idea? Thanks!</p>