c++ - 从 DLL 中建立 tcp 连接

Question

我正在尝试编写一段代码，允许我从 DLL 文件中建立 TCP 连接。这是我的情况:我有一个 ruby​​ 应用程序需要能够通过套接字发送和接收数据，但由于它将运行的环境，我无法访问 native ruby​​ 套接字方法。但是我可以访问一个 DLL 文件并运行其中的函数，所以我想我应该为 winsock 创建一个包装器。不幸的是，尝试使用一段应该连接到普通 C++ 应用程序中的 TCP 套接字的代码会引发大量 LNK2019 错误，我终生无法解决。

这是我用来连接的方法:

//Socket variable
SOCKET s;

//Establishes a connection to the server
int server_connect(char* addr, int port)
{

    //Start up Winsock
    WSADATA wsadata;

    int error = WSAStartup(0x0202, &wsadata);

    //Check if something happened
    if (error)
        return -1;



    //Verify Winock version
    if (wsadata.wVersion != 0x0202)
    {
        //Clean up and close
        WSACleanup();
        return -2;
    }

    //Get the information needed to finalize a socket
    SOCKADDR_IN target;
    target.sin_family = AF_INET; //Address family internet
    target.sin_port = _WINSOCKAPI_::htons(port); //Port #
    target.sin_addr.s_addr = inet_addr(addr);

    //Create the socket
    s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if (s == INVALID_SOCKET)
    {
        return -3;
    }

    //Try connecting
    if (connect(s, (SOCKADDR *)&target, sizeof(target)) == SOCKET_ERROR)
    {
        //Failed to connect
        return -4;
    }
    else
    {
        //Success
        return 1;
    }
}

我收到的确切错误是:

Error   1   error LNK2019: unresolved external symbol _closesocket@4 referenced in function _server_disconnect  [Project Path]
Error   2   error LNK2019: unresolved external symbol _connect@12 referenced in function _server_connect    [Project Path]
Error   3   error LNK2019: unresolved external symbol _htons@4 referenced in function _server_connect   [Project Path]
Error   4   error LNK2019: unresolved external symbol _inet_addr@4 referenced in function _server_connect   [Project Path]
Error   5   error LNK2019: unresolved external symbol _socket@12 referenced in function _server_connect [Project Path]
Error   6   error LNK2019: unresolved external symbol _WSAStartup@8 referenced in function _server_connect  [Project Path]
Error   7   error LNK2019: unresolved external symbol _WSACleanup@0 referenced in function _server_connect  [Project Path]
Error   8   error LNK1120: 7 unresolved externals   [Project Path]  1   1   

非常感谢!

Answer 1

这是预料之中的。在现代 Windows 系统上将您的项目与 Ws2_32.lib 链接。您的可执行文件将选择同名的 DLL。