COM Interop and structures

[Andrew S. Giles]

Hello again!

I am back for more information, as I am moving into trying to utilize COM to
work with unmanaged code from C#. In C# I have a series of classes to
encapsulate data that needs to be gathered for a report. This data is
resident in an unmanaged bit of C++ code. We want to use COM to facilitate
the transfer of this data to the C# environment so the report may be
generated. MY plan is to develop a C# class and interface that will be
converted into a Type Library that the C++ code can use to put the data into
the C# environment, which will then process it as necessary.

My question is how to represent this data on the C# side, so that it will be
easily used in the C++ code. It is effectively a collection of Strings,
Booleans, and Doubles. I am unsure of how the Marshalling will work on
classes or structures defined in this manner.

This is a sample Class that is already defined in C#:

public class VLT_Q3K_Result_ PKT
{
private int profibusID;
public int ProfibusID
{
get { return profibusID; }
set { profibusID = value;}
}
private int channelID;
public int ChannelID
{
get { return channelID; }
set { channelID = value; }
}
private double measuredValue; // Channel 1 value
public double MeasuredValue
{
get { return measuredValue; }
set { measuredValue = value; }
}
private bool testOrReference ;
public bool TestOrReference
{
get { return testOrReference ; }
set { testOrReference = value; }
}
private int resultMessage;
public int ResultMessage
{
get { return resultMessage;}
set { resultMessage = value;}
}
private int statusMessage;
public int StatusMessage
{
get { return statusMessage;}
set { statusMessage = value; }
}
private int testPulseValue;
public int TestPulseValue
{
get { return testPulseValue; }
set { testPulseValue = value; }
}

This is the basics for the class as it is already in use in C#. Should I
wrap this class to get the data across, or develop a new class, wrap it, and
then use it to populate the data into the class above?

I would prefer to have just one function call across the COM interop to get
all of the data across, so it is better to send a long list of parameters
(40-ish) one time, or to send a structure or class containing the data?

Any hints tips or suggestions would be most helpful.

Thanks in advance,

Andrew S. Giles