How to use a Cbuilder DLL that contains classes from C# 2005

[avmih]

Hello,

Please help me to use a CBuilder DLL that contains classes from Visual Studio C# 2005, I have problems with the underscores.

I used a well-known example which creates a DLL in Cbuilder 5 (use VCL set, source C++) and I named it DLLProject.dll:

#include <vcl.h>
#include <windows.h>
#pragma hdrstop

#include <windows.h>
#pragma argsused

double BoxArea(double L, double H, double W);
double BoxVolume(double L, double H, double W);

extern "C" __declspec(dllexport)void BoxProperties(double Length, double Height,
                                    double Width, double& Area, double& Volume);

BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fwdreason, LPVOID lpvReserved)
{
        return 1;
}
//---------------------------------------------------------------------------
double BoxArea(double L, double H, double W)
{
    return 2 * ((L*H) + (L*W) + (H*W));
}
//---------------------------------------------------------------------------
double BoxVolume(double L, double H, double W)
{
    return L * H * W;
}
//---------------------------------------------------------------------------
void BoxProperties(double L, double H, double W, double& A, double& V)
{
    A = BoxArea(L, H, W);
    V = BoxVolume(L, H, W);
}

I tested the dll in Cbuilder 5, using C convention and Generate underscores On, and it worked.

Next step I rebuild the dll this time using Generate underscores Off, and I called this dll from C# 2005 as in the following example:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace UnManaged
{
    public partial class Form1 : Form
    {

        [DllImport("DLLProject.dll")]
        static extern void BoxProperties(double L, double H, double W,
                                 double[] A, double[] V);
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            double myLength=2, myHeight=3, myWidth=4;
            double[] myArea = new double [1];
            double[] myVolume = new double [1];
            
            BoxProperties(myLength, myHeight, myWidth, myArea, myVolume);

        }
    }
}

and it worked again.

My problem is when I have a class in my DLL project under CBuilder, I can’t just build it with Generate underscores unset because I receive a link error:

Unresolved external ‘_Class Create’ referenced from …

How can I get rid off the underscores from my CBuilder dll if I build it with Generate underscores set, in order to use it in my C# code
?
Or other solution to resolve this issue?

Thank you

 

[2ffat]

Unresolved external '_Class Create' referenced from ...

That's a standard C++ linker error. You need to make sure you link the correct library(ies). See if this site can help.



James P. Cottingham
^{I'm number 1,229!
I'm number 1,229!}