topic FeatureSet.ObjectIDs in ArcGIS API for Silverlight Questions

FeatureSet.ObjectIDs

TedChapin — Sat, 19 Mar 2011 12:45:25 GMT

In a query completed event, where e is a QueryEventArgs, how can the following be true?

?e.FeatureSet.Count
10
?e.FeatureSet.ObjectIDs.Count
0

Isn't the ObjectIDs property of a FeatureSet an IEnumerable(of Object) representing the Object IDs of the query result? I'm trying to do a ExecuteRelationshipQueryAsync with a RelationshipParameter that contains all the same Object IDs as the query result, basically get all the records from a related table that correspond to a query result. Seems like a lot of legwork to manually construct a new IEnumerble(Of Integer) to populate the RelationshipParameter.ObjectIDs. Why not just RelationshipParameter.ObjectIDs = FeatureSet.ObjectIDs?

Ted Chapin

Re: FeatureSet.ObjectIDs

TedChapin — Sat, 19 Mar 2011 13:58:47 GMT

I just discovered that if the Query.ReturnIdsOnly property is set to True, then the ObjectIDs property of the FeatureSet of the result is populated, but the features themselves are not. If this property if False, then you get features but not the ObjectIDs. Weird.

I manually created a List(of Integer), looped through the FeatureSet and added the object ID's using feature.Attributes("OBJECTID"). Not my favorite approach but it worked.

Ted Chapin

Re: FeatureSet.ObjectIDs

JenniferNery — Mon, 21 Mar 2011 18:42:00 GMT

What you have observed is correct and is documented in REST API: http://help.arcgis.com/en/arcgisserver/10.0/apis/rest/query.html