Binding RectangleGeometry.Rect doesn't show the rectangle

Question

I'm having an issue trying to bind to a RectangleGeometry's Rect property. The basic idea here is that I'm attempting to bind a clip mask to control the visualized height of a pseudo-chart object. Here's the XAML:

  <Path x:Name="_value" Fill="{DynamicResource PositiveColorBrush}" Data="F1 M10,55 C10,57.75 7.75,60 5,60 2.25,60 0,57.75 0,55 L0,5 C0,2.25 2.25,0 5,0 7.75,0 10,2.25 10,5 L10,55 z">
     <Path.Clip>
        <!-- SECOND NUMBER CONTROLS THE HEIGHT : SCALE OF 0-60 REVERSED -->
        <!--<RectangleGeometry Rect="0,22.82,10,60"/>-->
        <RectangleGeometry 
           Rect="{Binding Score, Converter={StaticResource ChartBarScoreConverter}}" />
     </Path.Clip>
  </Path>

Note the commented RectangleGeometry there. That works perfectly when I uncomment it and comment out the bound RectangleGeometry. Of course, it won't change size when the Score changes, though.

Now, if I place a breakpoint in the ChartBarScoreConverter, I get the proper value and return a new RectangleGeometry object of the exact same specs as the commented out one there. Here's the short code of the converter:

  ...
  public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
  {
     RectangleGeometry output = new RectangleGeometry();
     double score = 60; //0
     if (Common.IsNumeric(value))
     {
        score = System.Convert.ToDouble(value) * .60;//scale is 0-60
        score = 60 - score;//reversed (=
     }
     output.Rect = new Rect(0, score, 10, 60);
     return output;
  }
  ...

When the app is run, it simply doesn't show the clip. As I said, I put a breakpoint in the converter and have verified that it's called and that an object of the correct size is returned... but it just doesn't appear in the view.

Any ideas?

Thanks, Paul

Answer 1

Your converter is returning a RectangleGeometry which you're then trying to assign to the Rect property of type Rect on a RectangleGeometry. Get rid of the "output" object in the converter and just return the Rect itself.