Can't save persisted IGeometry object into an ObjectStream

Question

I was able to store a serialized IGeometry object into an string field in a datatable from a File Geodatabase.

For performance issues and since the object implements IPersistStream, I want to save the original IGeometry object into a blob field.

So far I'm allowed to cast the geometry to IPersistStream but haven't been able to save it to an ObjectStream

I'm using ArcObjects SDK 10.3.1. Here's the code:

// Insert Geometry to DataTable.
fieldIndex = errorsTable.FindField(m_dataBaseConstants.DataTables.Fields.Geometry);
IObjectStream objectStream = new ObjectStream();
ESRI.ArcGIS.Geometry.IGeometry geom = dataToken.Geometry;
IPersistStream persistStream = (IPersistStream)geom;
// This line throws COMException (0x80004005)
persistStream.Save(objectStream, 0);
errorRow.Value[fieldIndex] = objectStream;

I have no clue why I'm not being able to save. Can you see the problem there?

Answer 1

I've come with a workaround. @MichaelStimson 's comment about a potential wrong cast helped and made me think to go and just try with another stream object.

IMemoryBlobStream just worked fine for me:

IMemoryBlobStream memoryBlobStream = new MemoryBlobStreamClass();
IGeometry geom = dataToken.Geometry;
IPersistStream persistStream = (IPersistStream)geom;
persistStream.Save(memoryBlobStream, 0);    
errorRow.Value[fieldIndex] = memoryBlobStream;

And then to unblob the persisted object to an IGeometry:

IMemoryBlobStream memoryBlobStream = new MemoryBlobStreamClass();
IPersistStream blob = default(IPersistStream);
memoryBlobStream = blobGeometry as IMemoryBlobStream;

if (geometryType.Equals(esriGeometryType.esriGeometryPoint.ToString()))
{
    blob = new PointClass();
}
else if (geometryType.Equals(esriGeometryType.esriGeometryPolyline.ToString()))
{
    blob = new PolylineClass();
}
else if (geometryType.Equals(esriGeometryType.esriGeometryPolygon.ToString()))
{
    blob = new PolygonClass();
}

blob.Load(memoryBlobStream);
IGeometry geometry = blob as IGeometry;

This solves my performance issue when trying to deserialize all the geometries of the table.