search cursor - spatialfilter - query for multipart polygon - arc 10 desktop

tonydavid

Does anyone know why multipart polygon doesn't work with this??

            pGridGeom = pGridFeature.Shape
            pGridSpatialFilter = New SpatialFilterClass
            With pGridSpatialFilter
                .GeometryField = pFeatcls.ShapeFieldName
                ' .SpatialRel = esriSpatialRelEnum.esriSpatialRelIntersects
                .SpatialRel = esriSpatialRelEnum.esriSpatialRelWithin
                .Geometry = pGridGeom
            End With
            pCursor = pFeatcls.Search(pGridSpatialFilter, True)

Should we 'explode' multipart poly into geometries?? Tried this but doesn't work ...

                If pGeomColl.GeometryCount > 1 Then
                    For i As Integer = 0 To pGeomColl.GeometryCount - 1
                        Dim pPolygonNew As IPolygon
                        Dim NewGeometryArray(0) As IGeometry
                        NewGeometryArray(0) = pGeomColl.Geometry(i)
                        Dim gBridge As IGeometryBridge = New GeometryEnvironment()
                        gBridge.AddGeometries(pPolygonNew, NewGeometryArray)
                        pGridGeom = pPolygonNew
                    Next
                 endif

Any help or suggestions?? Cheers.

NeilClemmons_GISinc

It sounds like a problem with the geometry itself.  When you view its record in the layer's attribute table, does it have a positive area?  If the area is negative (or 0) then the polygon is oriented incorrectly.  You might also try simplifying the geometry before using it in the query.

Dim topoOp As ITopologicalOperator2 = CType(geometry, ITopologicalOperator2) topoOp.IsKnownSimple_2 = False topoOp.Simplify()

Another possibility is the polygon and the layer you are querying do not share the same spatial reference.  If this is the case you should set the OutputSpatialReference property on the spatial filter using the spatial reference of the polygon.