编译DLL(CURL库)(Visual Studio)时出现问题

Question

我在C++中编译DLL时遇到问题。我正在使用CURL库进行HTTP POST。

当我将代码编译为控制台应用程序时，不会出现编译错误。但同样的代码会出现未解决的外部符号错误。

行如：

curl_global_init(CURL_GLOBAL_DEFAULT);
curl = curl_easy_init();
curl_easy_setopt(...);
curl_mime_name(...);

dll出了什么问题？缺少什么？

这是代码：

// dllmain.cpp : Defines the entry point for the DLL application.
#define CURL_STATICLIB
#include "pch.h"
#include "CURL/curl.h"
#pragma comment (lib, "CURL/libcurl_a.lib")
__declspec(dllexport) int httpPOST();
BOOL APIENTRY DllMain(HMODULE hModule,
DWORD  ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
case DLL_THREAD_ATTACH:
case DLL_THREAD_DETACH:
case DLL_PROCESS_DETACH:
break;
}
return TRUE;
}
int httpPOST() {
CURL* curl;
CURLcode res;
curl_global_init(CURL_GLOBAL_DEFAULT);
curl = curl_easy_init();
if (curl) {
curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
curl_easy_setopt(curl, CURLOPT_URL, "http://example.com/");
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
curl_easy_setopt(curl, CURLOPT_DEFAULT_PROTOCOL, "https");
struct curl_slist* headers = NULL;
headers = curl_slist_append(headers, "Cookie: cmslog=1");
curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
curl_mime* mime;
curl_mimepart* part;
mime = curl_mime_init(curl);
part = curl_mime_addpart(mime);
curl_mime_name(part, "username");
curl_mime_data(part, "user", CURL_ZERO_TERMINATED);
part = curl_mime_addpart(mime);
curl_mime_name(part, "requestcode");
curl_mime_data(part, "123456", CURL_ZERO_TERMINATED);
}
return 0;
}

httpPOST((中的代码在控制台应用程序中编译时没有问题。

错误为：

错误LNK2001未解析的外部符号__imp__curl_global_init

错误LNK2001未解析的外部符号__imp__curl_easy_init

错误LNK2001未解析的外部符号__imp__curl_easy_stopt

错误LNK2001未解析的外部符号__imp__curl_slist_append

错误LNK2001未解析的外部符号__imp__curl_mime_init

。。。

错误LNK1120 8未解析的外部

Answer 1

问题按#define CURL_STATICLIB顺序出现。

核心订单为：

#include "pch.h"
#define CURL_STATICLIB
#include "CURL/curl.h"

谢谢大家的帮助。