C++ NetLink Sockets Error - c++

Question

I recently started again on a C++ application. I am using NetLink for Sockets and Visual Studio for developing.
I made a small code but I got some errors. I've included the files from NetLink and I added ws2_32.lib (in linker/general & as pragma comment), but I still got these errors:
Error 1 error LNK2019: unresolved external symbol "void __cdecl NL::init(void)" (?init#NL##YAXXZ) referenced in function _main c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 4 error LNK2019: unresolved external symbol "public: class NL::Socket * __thiscall NL::Socket::accept(void)" (?accept#Socket#NL##QAEPAV12#XZ) referenced in function "private: virtual void __thiscall OnAccept::exec(class NL::Socket *,class NL::SocketGroup *,void *)" (?exec#OnAccept##EAEXPAVSocket#NL##PAVSocketGroup#3#PAX#Z) c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 6 error LNK2019: unresolved external symbol "public: bool __thiscall NL::SocketGroup::listen(unsigned int,void *)" (?listen#SocketGroup#NL##QAE_NIPAX#Z) referenced in function _main c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 5 error LNK2019: unresolved external symbol "public: __thiscall NL::SocketGroup::SocketGroup(void)" (??0SocketGroup#NL##QAE#XZ) referenced in function _main c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 2 error LNK2019: unresolved external symbol "public: __thiscall NL::Socket::Socket(unsigned int,enum NL::Protocol,enum NL::IPVer,class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > const &,unsigned int)" (??0Socket#NL##QAE#IW4Protocol#1#W4IPVer#1#ABV?$basic_string#DU?$char_traits#D#std##V?$allocator#D#2##std##I#Z) referenced in function _main c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 3 error LNK2019: unresolved external symbol "public: __thiscall NL::Socket::~Socket(void)" (??1Socket#NL##QAE#XZ) referenced in function _main c:\Users\Joshua\documents\visual studio 2012\Projects\OBPP\OBPP\Main.obj
Error 7 error LNK1120: 6 unresolved externals c:\users\joshua\documents\visual studio 2012\Projects\OBPP\Debug\OBPP.exe
Code I'm using (just wanted to try out accepting):
#include <iostream>
#include "netlink\socket.h"
#include "netlink\socket_group.h"
#pragma comment(lib, "Ws2_32.lib")
#define PORT 30000
class OnAccept: public NL::SocketGroupCmd {
void exec(NL::Socket* socket, NL::SocketGroup* group, void* reference) {
NL::Socket* newConnection = socket->accept();
group->add(newConnection);
std::cout << "\nConnection " << newConnection->hostTo() << ":" << newConnection->portTo() << " added...";
std::cout.flush();
}
};
int main()
{
NL::init();
NL::Socket s(PORT);
NL::SocketGroup group;
group.setCmdOnAccept(&OnAccept());
group.add(&s);
if (group.listen(2000))
{
std::cout << "Listening on Sockets, port " << PORT << std::endl;
}
getchar();
}

Answer 1

I am the developer of the library. It can't be used with the headers only, you need to link the static/dynamic compiled library.
You have to build the library first, to generate the .lib file. Once you have the netLink.lib file built (or whatever you name it) you have to add that dependency to the linker.

Answer 2

I am not visual studio developer, But error message says unresolved external symbol means linker is not able to find some symbols.
Look at you linking command does it include Netlink library?