Попробуй ещё раз
</Button>
<Button Height="30" Width="30" Margin="0,0,2,0"
HorizontalContentAlignment="Left" Padding="3" ToolTipService.ToolTip="Линейка">
<i:Interaction.Triggers>
<i:EventTrigger EventName="Click">
<esri:MeasureAction
AreaUnit="SquareMeters"
DisplayTotals="True"
DistanceUnit="Meters"
MapUnits="Meters"
MeasureMode="Polyline"
TargetName="MyMap">
</esri:MeasureAction>
</i:EventTrigger>
</i:Interaction.Triggers>
<Image Source="/Showcase;component/Images/LayerCAD32.png" Margin="2" />
</Button>
у меня работает на ура
http://astanamap.kz/cityface