BinaryFormatter在转换Int32和Double等内部对象时出现问题

我正在编写c++混合模式DLL并将从数据库读取的对象转换为非托管代码变量。我试图将object转换为字节数组，以便我可以将其值逐字节复制到非托管内存。

当我进行转换时，我得到的不仅仅是字节数组中对象的数据。

下面是我的代码示例:

// Convert an object to a byte array
static array<System::Byte>^ ObjectToByteArray(Object^ obj)
{
    if (obj->Equals(nullptr))
        return nullptr;
    BinaryFormatter^ bf = gcnew BinaryFormatter();
    MemoryStream^ ms = gcnew MemoryStream();
    bf->Serialize(ms, obj);
    return ms->ToArray();
}
void dtmControlLimits() {
    OdbcDataReader^ reader;
    // ...
    Object oVal = reader->GetValue(ordinalPositionColumn);
    array<System::Byte, 1>^ ab = ObjectToByteArray(oVal);
    pin_ptr<System::Byte> pp = &ab[0];
    char *p = (char *)pz->zMap.pValue;
    for (size_t i = 0; i < knSizeOf; i++, p++){
      *p = ab[i];
    }
    // ...
}

返回的数组ab看起来像是Int32对象的结构体，而不仅仅是它的值。

我想获得一个byte[]与对象的值，以便我可以将其逐字节复制到非托管数据。

如果oVal是Int32和*oVal = 0x12345678，那么这里是ab的内存转储:

0x03A45954  00 01 00 00 00 ff ff ff ff 01 00 00 00 00 00 00 00 04  .....ÿÿÿÿ.........
0x03A45966  01 00 00 00 0c 53 79 73 74 65 6d 2e 49 6e 74 33 32 01  .....System.Int32.
0x03A45978  00 00 00 07 6d 5f 76 61 6c 75 65 00 08 78 56 34 12 0b  ....m_value..xV4..

oVal的值在字段名m_value后面的最后一行。由于oVal是从数据库中读取的，因此在编译时无法确定其数据类型。

我怎么能得到对象的值，而不是整个对象的数据结构，到字节[]ab?

=========================================================

2014年6月12日更新

这是使用DAO的旧MFC代码的更新，我想将旧的32位应用程序更新为64位应用程序。要做到这一点，我必须重写DAO代码以使用ADO。Net，因为DAO只有32位可用。

我真的很想避免为内存复制设置开关，但看起来我被迫生活在。net的限制中。旧的MFC代码允许我使用memcpy()将DAO记录集数据传输到适当的变量。这是一种更新数据的直接方法。

使用switch语句似乎没有必要且复杂。我本想避免的。

谁有更好的主意?

static ViStatus ReaderToTag(
    pzDataTag_t pz
    , String^ sColumnName
    , IDataReader^ reader)
{
    ViStatus errStatus = VI_SUCCESS;
    array<System::Byte, 1>^ ab;
    if (pz) {
        const MM_eVppType_t keVppType = pz->zMap.eVppType;
        const size_t knSizeOf = MM_VPPTYPE_SIZEOF(keVppType);
        Object^ oVal = reader[sColumnName];
        Type^ typ = oVal->GetType();
        switch (Type::GetTypeCode(typ)) {
        case System::TypeCode::Byte:
            ab = BitConverter::GetBytes((Byte)oVal);
            break;
        case System::TypeCode::Char:
            ab = BitConverter::GetBytes((Char)oVal);
            break;
        case System::TypeCode::DateTime:
        {
            DateTime^ date = (DateTime)oVal;
            TimeSpan^ diff = date->ToUniversalTime() - DateTime(1970, 1, 1);
            *(time_t *)pz->zMap.pValue = static_cast<std::time_t>(diff->TotalMilliseconds);
            break;
        }
        case System::TypeCode::Decimal:
        {
            array<int>^ bits = Decimal::GetBits((Decimal)oVal);
            System::Array::Resize(ab, sizeof(Decimal));
            System::Buffer::BlockCopy(bits, 0, ab, 0, ab->Length);
            break;
        }
        case System::TypeCode::Double:
            ab = BitConverter::GetBytes((Double)oVal);
            break;
        case System::TypeCode::Int16:
            ab = BitConverter::GetBytes((Int16)oVal);
            break;
        case System::TypeCode::Int32:
            ab = BitConverter::GetBytes((Int32)oVal);
            break;
        case System::TypeCode::Int64:
            ab = BitConverter::GetBytes((Int64)oVal);
            break;
        case System::TypeCode::Object:
            break;
        case System::TypeCode::SByte:
            ab = BitConverter::GetBytes((SByte)oVal);
            break;
        case System::TypeCode::Single:
            ab = BitConverter::GetBytes((Single)oVal);
            break;
        case System::TypeCode::String:
        {
            String ^ str = Convert::ToString(oVal);
            char *pcSrc = (char*)(void*)Marshal::StringToHGlobalAnsi(str);
            char *pcDest = (char *)pz->zMap.pValue;
            for (int i = 0; i < min(str->Length, pz->zMap.nArySize - 1); i++, pcSrc++, pcDest++) {
                *pcDest = *pcSrc;
            }
            *pcDest = 0;
            break;
        }
        case System::TypeCode::UInt16:
            ab = BitConverter::GetBytes((UInt16)oVal);
            break;
        case System::TypeCode::UInt32:
            ab = BitConverter::GetBytes((UInt32)oVal);
            break;
        case System::TypeCode::UInt64:
            ab = BitConverter::GetBytes((UInt64)oVal);
            break;
        case System::TypeCode::Empty:
        case System::TypeCode::DBNull:
        default:
            goto AbortOnError;
        }
        if (ab && ab->Length) {
            pin_ptr<System::Byte> pp = &ab[0];
            char *p = (char *)pz->zMap.pValue;
            for (size_t i = 0; i < min((size_t)ab->Length, knSizeOf); i++, p++){
                *p = ab[i];
            }
            //memcpy(pz->zMap.pValue, (char*)pp, knSizeOf);
        }
        Debug::WriteLine(sColumnName->ToString()
            + "=" + oVal->ToString()
            + ", typ=" + typ->ToString());
    }
    return errStatus;
AbortOnError:
    if (VI_SUCCESS == errStatus) errStatus = mmGrasp_eErr_Unspecified;
    if (MM_pfnRunStatus) MM_pfnRunStatus("... mmDotNet_dtmControlLimitsToTags: Error");
    return errStatus;
} // ReaderToTag()