Access voilation c++ builder when calling dll dynamically.

[RahulBhutani]

Hello im trying to call a dll function from c++ builder and getting access violation.

The same code work fine in vc++ console.

can anyone check whats wrong im doing ??

DLL Code.

#include <string>
#include <vector>
#include <regex>

using namespace std;

extern "C" __declspec(dllexport)void xmlResponse(string& myString,vector<string>& vec)
{
regex rx("</data>");
vector<int> index_matches;
for (auto it = std::sregex_iterator(myString.begin(), myString.end(), rx);it != std::sregex_iterator();++it)
{
index_matches.push_back(it->position());
}
for (unsigned int i = 0; i < index_matches.size(); i++)
{
string tmp;
if (i == 0)
{
tmp = myString.substr(0, index_matches[i] + 7);
vec.push_back(tmp);
}
else
{
tmp = myString.substr(index_matches[i - 1] + 7, index_matches[i] - index_matches[i - 1]);
vec.push_back(tmp);
}
}
}

Button code in c++ builder.

typedef void (*xmlResponse)(string&, vector<string>&);
string myString =
"<?xmlversion=\"1.0\" ?><data><read SECTOR_SIZE_IN_BYTES=\"512\" num_partition_sectors=\"34\" physical_partition_number=\"0\" start_sector=\"0\"/></data><?xmlversion=\"2.0\" ?><data><read SECTOR_SIZE_IN_BYTES=\"512\" num_partition_sectors=\"34\" physical_partition_number=\"0\" start_sector=\"0\"/></data>";
HINSTANCE dllAccess = LoadLibraryA("C:\\Users\\Rahul\\Documents\\Visual Studio 2015\\Projects\\xmlRegex\\Debug\\xmlRegex.dll");
if (!dllAccess)
{
cout << "Dll Not Found" << endl;
}
xmlResponse xRes;
xRes = (xmlResponse)GetProcAddress(dllAccess, "xmlResponse");
vector<string> x;
xRes(myString, x); // getting error here.

[Golden Lizard]

Have you properly linked the dll from your project?

[Thomas1965]

xRes = (xmlResponse)GetProcAddress(dllAccess, "xmlResponse");
You should check that xREs is not 0. Also it is quite dangerous to pass objects to a dll.

http://stackoverflow.com/questions/22797418/how-do-i-safely-pass-objects-especially-stl-objects-to-and-from-a-dll