How to pass byte array parameter from C# to C++

[juhaka]

Hi!

Now I have a need to pass byte array (byte[]) parameter from C# component to C++ component (and vice versa). So, I have an old C++ component, which have a function like unsigned char* encode(unsigned char* arrBytes). I thought, that I will do a wrapper class for it, but how...

JuhaKa

 

[juhaka]

Hi!

I found one solution for this problem by myself...I'm not sure is it the rigth (and only) one....

This is an example...please send yuor comments, if here is fatal errors.

The wrapper class
The header.

// StringConverter.h

#pragma once
#include "Converter.h"
using namespace System;

namespace StringConverter
{
public __gc class StrConverter: public IDisposable
{
private:
Converter *conv;
public:
StrConverter();
~StrConverter();
System::Byte ToLower(System::Byte str __gc[])[];
void Dispose(bool disposing);
void Dispose();

};
}



The cpp code.

// This is the main DLL file.

#include "stdafx.h"
#include <stdio.h>
#include "string.h"
#include "Converter.h"

#include "StringConverter.h"

using namespace System::Runtime::InteropServices;

StringConverter::StrConverter::StrConverter()
{
conv = new Converter();
}

StringConverter::StrConverter::~StrConverter()
{
printf("\nDestructor...");
this->Dispose(false);

}

void StringConverter::StrConverter:ispose()
{
printf("\nDispose()....");
this->Dispose(true);
}

void StringConverter::StrConverter:ispose(bool disposing)
{
printf("\nDispose(bool disposing)...");
if(this->conv != NULL)
{
delete conv;
conv = NULL;
}
if(disposing == true)
{
GC::SuppressFinalize(this);
}
}


System::Byte StringConverter::StrConverter::ToLower(System::Byte str __gc[])[]
{
unsigned char* buff = new unsigned char[str->Length + 1];

//copying byte array to the pointer...
Marshal::Copy(str, 0, buff, str->Length);
printf("buff: %s", buff);
unsigned char* ts = buff;
for(int i = 0; i < str->Length; i++)
{
ts++;
}
*ts = NULL;
printf("\nbuff: %s", buff);
int len = 0;

//calling original C++ function !!!
unsigned char* tmp = this->conv->toLower(buff, &len);

//Copying returned value to new byte array
System::Byte retBytes __gc[] = new System::Byte __gc[len - 1];
Marshal::Copy(tmp, retBytes, 0, retBytes->Length);

//free memory...
delete [] buff;
buff = NULL;
delete [] tmp;
tmp = NULL;
return retBytes;
}



Juha Ka