Question

MFC CArray was Serialized and saved to a database. I need to read this data into a C# project. I am able to retrieve the data as byte[] from the database. I then write the byte[] to a MemoryStream. Now I need to read the data from the MemoryStream.

Someone has apparently solved this before, but did not write their solution.

http://social.msdn.microsoft.com/Forums/eu/csharpgeneral/thread/17393adc-1f1e-4e12-8975-527f42e5393e

I followed these projects in my attempt to solve the problem.

http://www.codeproject.com/Articles/32741/Implementing-MFC-Style-Serialization-in-NET-Part-1

http://www.codeproject.com/Articles/32742/Implementing-MFC-Style-Serialization-in-NET-Part-2

The first thing in the byte[] is the size of the array, and I can retrieve that with binaryReader.readInt32(). However, I cannot seem to get back the float values. If I try binaryReader.readSingle() or

public void Read(out float d) {
    byte[] bytes = new byte[4];
    reader.Read(bytes, m_Index, 4);
    d = BitConverter.ToSingle(bytes, 0);
}

I do not get back the correct data. What am I missing?

EDIT Here is the C++ code that serializes the data

typedef CArray<float, float> FloatArray;
FloatArray floatArray;
// fill floatArray
CSharedFile memoryFile(GMEM_MOVEABLE | GMEM_ZEROINIT);
CArchive ar(&memoryFile, CArchive::store); 
floatArray.Serialize(ar);
ar.Close();

EDIT 2

By reading backward, I was able to get all of the floats, and was also able to determine that the size for CArray is byte[2], or Int16. Does anyone know if this is always the case?

Answer 1

Using the codeproject articles above, here is a C# implementation of CArray which will allow you to deserialize a serialized MFC CArray.

// Deriving from the IMfcArchiveSerialization interface is not mandatory
public class CArray : IMfcArchiveSerialization {
    public Int16 size;
    public List<float> floatValues;

    public CArray() {
        floatValues = new List<float>();
    }

    virtual public void Serialize(MfcArchive ar) {
        if(ar.IsStoring()) {
            throw new NotImplementedException("MfcArchive can't store");
        }
        else {
            // be sure to read in the order in which they were stored
            ar.Read(out size);

            for(int i = 0; i < size; i++) {
                float floatValue;
                ar.Read(out floatValue);
                floatValues.Add(floatValue);
            }
        }
    }
}