UniqueValueRenderer.DefaultLabel or How to Handle Null Values

DTMGIS

I think that this is simple, but it is eluding me.

Using a UniqueValueRenderer, how do you handle Null values in the attribute field? I have a simple Attribute Field that is either "X" or is Null. Displaying the features that are attributed with "X" is simple. And I can get the features with Null to display if I use a DefaultSymbol to catch the uncategoriezed values. But I can't figure out how to get a Label in the legend for the DefaultSymbol. There appears to be a DefaultLabel property, but I can't seem to implement it.

Here's what I have:

<esri:UniqueValueRenderer x:Key="TrailsRenderer" Attribute="Snow">                      
                        <esri:UniqueValueRenderer.DefaultSymbol >
                            <esri:SimpleLineSymbol  Color="#70A800" Width="1.5" />
                        </esri:UniqueValueRenderer.DefaultSymbol>
                        <esri:UniqueValueRenderer.Infos>
                            <esri:UniqueValueInfo Value="" Label="Non-Motorized" Symbol="{StaticResource TrailsNonMotorSymbol}" />                            <esri:UniqueValueInfo Value="X" Label="Snowmobile" Symbol="{StaticResource TrailsSnomoSymbol}" />
                        </esri:UniqueValueRenderer.Infos>
                    </esri:UniqueValueRenderer>

I either want the "Non-Motorized" to show up as used in the UniqueValueInfo, or use the DefaultValue, but be able to include a label in the Table of Contents.

Thanks, as always!

-T

DominiqueBroux

You can hook up an handler to the legend refreshed event and set the label by code (knowning that the default symbol is the first item).

Something like:

private void Legend_Refreshed(object sender, Legend.RefreshedEventArgs e)
{
  if (e.LayerItem.Layer.Renderer is UniqueValueRenderer)
    e.LayerItem.LayerItems[0].Label = "Non-Motorized";
}