定义ZMQ_EXPORT __declspec（dllexport）

Question

我正在尝试在Visual Studio 2013上用C ++构建这个简单的ZeroMQ服务器。

#include "stdafx.h"
#include "zmq.hpp"
#include <string>
#include <iostream>
#include <windows.h>

using namespace std;

int _tmain(int argc, _TCHAR* argv[])
{
    // Prepare context and socket
    zmq::context_t ctx(1);
    zmq::socket_t sckt(ctx, ZMQ_REP);
    sckt.bind("tcp://*:5555");

    while (true) {
        zmq::message_t request;

        // Wait for next request from client
        sckt.recv(&request);
        std::cout << "Received Hello" << endl;
        Sleep(1);

        // Send reply back to client
        zmq::message_t reply(5);
        memcpy((void*)reply.data(), "World", 5);
        sckt.send(reply);
    }
    return EXIT_SUCCESS;
}

然而，当我尝试构建VS项目时，我收到错误LNK2019。下面是编译器输出：

1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_errno referenced in function "public: __thiscall zmq::error_t::error_t(void)" (??0error_t@zmq@@QAE@XZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_strerror referenced in function "public: virtual char const * __thiscall zmq::error_t::what(void)const " (?what@error_t@zmq@@UBEPBDXZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_ctx_new referenced in function "public: __thiscall zmq::context_t::context_t(int,int)" (??0context_t@zmq@@QAE@HH@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_ctx_set referenced in function "public: __thiscall zmq::context_t::context_t(int,int)" (??0context_t@zmq@@QAE@HH@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_ctx_destroy referenced in function "public: void __thiscall zmq::context_t::close(void)" (?close@context_t@zmq@@QAEXXZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_init referenced in function "public: __thiscall zmq::message_t::message_t(void)" (??0message_t@zmq@@QAE@XZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_init_size referenced in function "public: __thiscall zmq::message_t::message_t(unsigned int)" (??0message_t@zmq@@QAE@I@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_send referenced in function "public: bool __thiscall zmq::socket_t::send(class zmq::message_t &,int)" (?send@socket_t@zmq@@QAE_NAAVmessage_t@2@H@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_recv referenced in function "public: bool __thiscall zmq::socket_t::recv(class zmq::message_t *,int)" (?recv@socket_t@zmq@@QAE_NPAVmessage_t@2@H@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_close referenced in function "public: __thiscall zmq::message_t::~message_t(void)" (??1message_t@zmq@@QAE@XZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_msg_data referenced in function "public: void * __thiscall zmq::message_t::data(void)" (?data@message_t@zmq@@QAEPAXXZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_socket referenced in function "public: __thiscall zmq::socket_t::socket_t(class zmq::context_t &,int)" (??0socket_t@zmq@@QAE@AAVcontext_t@1@H@Z)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_close referenced in function "public: void __thiscall zmq::socket_t::close(void)" (?close@socket_t@zmq@@QAEXXZ)
1>ZeroMQServer.obj : error LNK2019: unresolved external symbol __imp__zmq_bind referenced in function "public: void __thiscall zmq::socket_t::bind(char const *)" (?bind@socket_t@zmq@@QAEXPBD@Z)
1>D:\[ Source Code ]\C++\ZeroMQServer\Debug\ZeroMQServer.exe : fatal error LNK1120: 14 unresolved externals
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

我已经安装了ZeroMQ binary v4.0.4并更新了VS项目属性以指向ZeroMQ的include和lib路径。具体来说，这是我在项目属性中更新的内容（我怀疑其中一些设置可能是多余的）：

配置属性＆gt; VC ++目录＆gt;包含目录：添加'$（ZEROMQ_HOME）\ include'
配置属性＆gt; VC ++目录＆gt;库目录：添加了'$（ZEROMQ_HOME）\ lib'
配置属性＆gt; C / C ++＆gt;一般＆gt;其他包含目录：添加'$（ZEROMQ_HOME）\ include'
配置属性＆gt;链接器＆gt;输入＆gt;其他依赖项：添加了'libzmq-v120-mt-4_0_4.lib; libzmq-v120-mt-gd-4_0_4.lib'

我在Win 7,64位版本上。请帮我解决这个问题。

Answer 1

根据zeromq.org上的库名称，您尝试将同一个库链接两次：首先是发布版本，然后是调试版本。

从发布配置中删除libzmq-v120-mt-gd-4_0_4.lib，然后从调试配置中删除libzmq-v120-mt-4_0_4.lib。

Answer 2

由于我想静态链接zmq，因此必须定义ZMQ_STATIC。默认情况下，所有这些功能定义为

elif定义的DLL_EXPORT

定义ZMQ_EXPORT __declspec（dllexport）

Answer 3

我有同样的错误。但对我来说，他们是由一套错误的召集惯例制作的。（只是想在这里提一下，因为跟踪它需要一个多小时。）

VS2013错误：LNK2019尝试构建ZeroMQ服务器时

3 个答案:

定义ZMQ_EXPORT __declspec（dllexport）