Dominique,
Can you instantiate web map from a portal item whose type is "feature service"? I'm trying to create a web map asynchronously from an ArcGISPortalItem that is simply a layer of type "feature service" and when I call WebMap.FromPortalItemAsync(...); I get an exception that reads "Invalid Item".
Is it expected that this constructor may only be called successfully with an ArcGISPortalItem object whose type is "web map" ?
If so, how can I get JUST a layer object from an ArcGISPortalItem whose type is one of the various web/desktop layer types?
Thanks,
- Aaron