IGeometryCollection outGeomColl = new GeometryBagClass() as IGeometryCollection; (outGeomColl as IGeometry).SpatialReference = (inFeatureClass as IGeoDataset).SpatialReference;
IBufferConstruction buffConst = new BufferConstructionClass(); IBufferConstructionProperties buffProp = buffConst as IBufferConstructionProperties; buffProp.DistancesSource = bufferDistance; buffProp.GeometriesSource = inGeometryColl as IEnumGeometry; ; buffProp.GeometriesSink = outGeomColl;
buffConst.ConstructBuffersByDistances(buffConst as IGeometricBufferSourceSink);