为什么我会收到"unresolved external symbol"消息？

我正试图使用IBM的EHLLAPI与他们的个人通讯器终端仿真器接口。我已经从这个页面复制了他们的示例代码，但当我试图构建它时，它给了我一个错误

1>------ Build started: Project: PCOMAPI, Configuration: Debug Win32 ------
1>  Source.cpp
1>Source.obj : error LNK2019: unresolved external symbol _hllapi@16 referenced in function _main
1>C:Users[username]DocumentsVisual Studio 2013ProjectsVPARSAPIDebugPCOMAPI.exe : fatal error LNK1120: 1 unresolved externals

我不完全确定这是什么_hllapi@16是，而我在代码中没有看到它。我已经有一段时间没有使用C++了，所以我可能缺少一些简单的东西。代码如下：

#include <stdlib.h>
#include <stdio.h>
#include <windows.h>
#include "hapi_c.h"

int main(char **argv, int argc) {
    int HFunc, HLen, HRc;
    char HBuff[1];
    struct HLDConnectPS ConnBuff;
    // Send Key string for HOME+string+ENTER:
    char SendString[] = "@0Hello World!@E";
    HFunc = HA_RESET_SYSTEM;
    HLen = 0;
    HRc = 0;
    hllapi(&HFunc, HBuff, &HLen, &HRc);
    if (HRc != HARC_SUCCESS) {
        printf("Unable to access EHLLAPI.n");
        return 1;
    }
    HFunc = HA_CONNECT_PS;
    HLen = sizeof(ConnBuff);
    HRc = 0;
    memset(&ConnBuff, 0x00, sizeof(ConnBuff));
    ConnBuff.stps_shortname = 'A';
    hllapi(&HFunc, (char *)&ConnBuff, &HLen, &HRc);
    switch (HRc) {
    case HARC_SUCCESS:
    case HARC_BUSY:
    case HARC_LOCKED: // All these are OK
        break;
    case HARC_INVALID_PS:
        printf("Host session A does not exist.n");
        return 1;
    case HARC_UNAVAILABLE:
        printf("Host session A is in use by another EHLLAPI application.n");
        return 1;
    case HARC_SYSTEM_ERROR:
        printf("System error connecting to session A.n");
        return 1;
    default:
        printf("Error connecting to session A.n");
        return 1;
    }
    HFunc = HA_SENDKEY;
    HLen = strlen(SendString);
    HRc = 0;
    hllapi(&HFunc, SendString, &HLen, &HRc);
    switch (HRc) {
    case HARC_SUCCESS:
        break;
    case HARC_BUSY:
    case HARC_LOCKED:
        printf("Send failed, host session locked or busy.n");
        break;
    default:
        printf("Send failed.n");
        break;
    }
    HFunc = HA_DISCONNECT_PS;
    HLen = 0;
    HRc = 0;
    hllapi(&HFunc, HBuff, &HLen, &HRc);
    printf("EHLLAPI program ended.n");
    return 0;
}

我的链接器标志是：

• /OUT："C:\Users[用户名]\Documents\Visual Studio2013\Projects\VPARSAPI\Debug\POCMAPI.exe"/MANIFEST/NXCCOMPAT
• /PDB:"C:\Users[用户名]\Documents\Visual Studio
• 2013\Projects\VPARSAPI\Debug\POCMAPI.pdb"/DDYNAMICBASE"kernel32.lib"
• "user32.lib"gdi53.lib"winspool.lib"comdlg32.lib""advapi32.lib"
• "shell32.lib"ole32.lib""oleaut32.lib"uuid.lib"odbc32.lib"
• "odbccp32.lib"/DEBUG/MACHINE:X86/INCREMENTAL
• /PGD:"C:\Users[用户名]\Documents\VisualStudio2013\Projects\VPARSAPI\Debug\POCMAPI.pgd"/SUBSYSTEM:CONSOLE
• /MANIFESTUAC:"level='asInvoker'uiAccess='false'"
• /ManifestFile:"调试\ PCOMAPI.exe.intermediate.manifest"
• /错误报告：PROMPT/NOLOGO/TLBID:1