Graphic tool - Draw Polygon Polygon disappears after finish drawing

Question

I am using arcGIS silverlight api 2.1 SDK. Created a button for drawing polygon using ESRI:RedlineAction

<esri:RedlineAction 
    Color="Red"
    DrawMode="Polygon"                                    
    GraphicsLayerID="MyGraphicsLayer" 
    TargetName="Map" />

when drawing is finished, the polygon disappears. I want it to stay so that it can be used when creating printouts. Drawing with polyline and freehand functions are fine though.  Anyone has the same problem?
Thanks very much

SomeGISGuy · Answer

If you use one of the built-in renderers, the symbol type much match the geometry type, and thus all geometry types must be the same in the layer.
 
If you don't use a renderer, you can simply assign a symbol directly to each graphic that matches for the geometry type.

Ying1 · Answer

Does that mean another graphics Layer have to be created for polygon rendering? The previous api example was able to accommadate both polyline and polygon on same graphic layer.
thanks

JenniferNery · Answer

If you are using this SDK sample: http://help.arcgis.com/en/webapi/silverlight/samples/start.htm#GraphicsActions Notice that the GraphicsLayer it uses is: This Renderer is for Polyline geometry. The graphic is not removed, it is just not rendered because its geometry type cannot be given line symbol. You need to use a different Renderer with symbols that match the geometry type for graphics drawn by RedlineAction.