System::String ^md5String;
md5String="admin";
IntPtr sptr = System::Runtime::InteropServices::Marshal::StringToHGlobalAnsi(md5String);
void* stemp = sptr.ToPointer();
char* pMd5Char = static_cast<char*>(stemp);
std::string s = MD5Encode(pMd5Char);
md5String=gcnew System::String(s.c_str());