One thing I've noticed though is that if the dynamic layer's projection doesn't match, it gets a white background when projected to match the map covering all layers underneath. Is this correct and if so is it by design, a known limitation, or something I can work around?
<Grid x:Name="LayoutRoot" > <esri:Map x:Name="MyMap"> <esri:ArcGISTiledMapServiceLayer ID="StreetMapLayer" Url="http://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer" InitializationFailed="Layer_InitializationFailed" /> <esri:ArcGISDynamicMapServiceLayer ID="DynamicLayer" Opacity="0.6" Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapSe..." InitializationFailed="Layer_InitializationFailed" /> </esri:Map> </Grid>
<esri:ArcGISDynamicMapServiceLayer ID="DynamicLayer" Opacity="0.6" ImageFormat="JPG" Url="http://sampleserver1.arcgisonline.com/ArcGIS/rest/services/Specialty/ESRI_StateCityHighway_USA/MapSe..." InitializationFailed="Layer_InitializationFailed" />
<esri:Map x:Name="map" Grid.ColumnSpan="4" Grid.Row="1"> <esri:Map.Extent> <esri:Envelope XMin="-130" YMin="10" XMax="-70" YMax="60" > <esri:Envelope.SpatialReference> <esri:SpatialReference WKID="4326"/> </esri:Envelope.SpatialReference> </esri:Envelope> </esri:Map.Extent> <esri:Map.Layers> <!-- imagery service in 4326 --> <esri:ArcGISTiledMapServiceLayer Url="http://services.arcgisonline.com/ArcGIS/rest/services/I3_Imagery_Prime_World_2D/MapServer"/> <!-- local dynamic service in 4269 --> <esri:ArcGISDynamicMapServiceLayer Url="http://myserver/ArcGIS/rest/services/test_service/MapServer/" /> </esri:Map.Layers> </esri:Map>