title: How to set FallbackValue in binding as path to external image file?
body: <p>I'm trying to set FallbackValue in case when my converter cannot be call, but I'm not sure how to do that.</p>
  
  <pre><code>&lt;Image Source="{Binding FallbackValue="Pictures/Unknown.png", Path=LatestPosition.DeviceFamily, Converter={x:Static conv:ConverterSet.DeviceTypeToImageSourceconverter}}" Name="image1" Stretch="Fill" Margin="5,8" Width="150" Height="150" Grid.RowSpan="4" /&gt;
  </code></pre>
  
  <p>Paths of external images in converter looks like that and when LatestPosition!=null the image is set in proper way.</p>
  
  <pre><code>private static readonly ImageSource Dev1 = new BitmapImage(new Uri("/Pictures/dev1.png", UriKind.Relative));
  private static readonly ImageSource Dev2 = new BitmapImage(new Uri("/Pictures/dev2.png", UriKind.Relative));
  </code></pre>