Extract BLOB Value using arcobject.
//Find Blob field Index suppose field index ia 2.
//Get the Blob Field from the Table.
ESRI.ArcGIS.Geodatabase.IFields fields = row.Fields;
ESRI.ArcGIS.Geodatabase.IField field = fields.get_Field(2);
//we also check the type of field
if (field.Type == ESRI.ArcGIS.Geodatabase.esriFieldType.esriFieldTypeBlob)
{
ESRI.ArcGIS.esriSystem.IMemoryBlobStream memoryBlobStream =
(ESRI.ArcGIS.esriSystem.IMemoryBlobStream)pRow.get_Value(pRow.Fields.FindField("pdf"));
memoryBlobStream.SaveToFile(mapPdfPath + "\\" + cmbMapName.Text + ".pdf");
Process.Start(mapPdfPath + "\\" + cmbMapName.Text + ".pdf");
return true;
}
else
{
//unsuccessful
return false;
}