HRESULT - IPersistStream.Save()

Question

I have converted a VB6 project to C#, and there is one problem I cannot find documentation on. I am saving an IPropertySet to file by using IMemoryBlobStream and IPersistStream, as seen here:

 public void WriteToFile(string fullPath)
    {
        IMemoryBlobStream pMemStream;
        IPersistStream pPersistStream;

        try
        {
            // Open Stream, must use memory stream instead of FileStream
            pMemStream = new MemoryBlobStreamClass();

            // Write PropertySet to Stream
            pPersistStream = (IPersistStream)m_pPropertySet;
            pPersistStream.Save(pMemStream, 1);

            // Save Stream to File
            pMemStream.SaveToFile(fullPath);
            pMemStream = null;

        }
        catch (Exception ex)
        {
            return;
        }
    }

I get an "HRESULT E_FAIL" with error code "-2147467259" on pPersistStream.Save(pMemStream, 1);

This doesn't throw an error if the PropertySet is empty, only if it has properties within.

When the PropertySet is populated, it is populated by Long data types (int64). Using PropertySet.SetProperty(Name, Value)

Any ideas why this would work great in ArcGIS 8/9 and not in 10 with C#?

Answer 1

This error is caused by byte size of value, not ArcGIS version. VB6 long type is 4 byte (32 bit Integer), and .NET long type is 8 byte (64 bit Integer). However, I'm not sure why Stream class cannot use it. But in any case, .NET int type is same as VB6 long type, so you may use int type instead.