虽然有点晚了。你可能更喜欢https://github.com/Taymindis/backcurl。

它允许你在移动c++开发上进行http调用。适合手机游戏开发

bcl::init(); // init when using

bcl::execute<std::string>([&](bcl::Request *req) {
    bcl::setOpts(req, CURLOPT_URL , "http://www.google.com",
             CURLOPT_FOLLOWLOCATION, 1L,
             CURLOPT_WRITEFUNCTION, &bcl::writeContentCallback,
             CURLOPT_WRITEDATA, req->dataPtr,
             CURLOPT_USERAGENT, "libcurl-agent/1.0",
             CURLOPT_RANGE, "0-200000"
            );
}, [&](bcl::Response * resp) {
    std::string ret =  std::string(resp->getBody<std::string>()->c_str());
    printf("Sync === %s\n", ret.c_str());
});


bcl::cleanUp(); // clean up when no more using

现在正在开发一种更新的、不太成熟的卷曲包装器，称为c++ Requests。下面是一个简单的GET请求:

#include <iostream>
#include <cpr.h>

int main(int argc, char** argv) {
    auto response = cpr::Get(cpr::Url{"http://httpbin.org/get"});
    std::cout << response.text << std::endl;
}

它支持各种各样的HTTP动词和curl选项。这里有更多的使用文档。

免责声明:我是这个库的维护者。

libCURL是一个非常好的选择。根据你需要做什么，教程应该告诉你你想要什么，特别是简单的操作。但是，基本上，你可以这样做只是为了查看页面的源代码:

CURL* c;
c = curl_easy_init();
curl_easy_setopt( c, CURL_URL, "www.google.com" );
curl_easy_perform( c );
curl_easy_cleanup( c );

我相信这将导致结果被打印到标准输出。如果您想要处理它——我假设您是这样做的——您需要设置CURL_WRITEFUNCTION。上面链接的curl教程中介绍了所有这些内容。

下面是一些无需使用任何第三方库即可工作的代码: 首先定义网关、用户、密码和需要发送到此特定服务器的任何其他参数。

#define USERNAME "user"
#define PASSWORD "your password"
#define GATEWAY "your gateway"

下面是代码本身:

HINTERNET hOpenHandle, hResourceHandle, hConnectHandle;
const TCHAR* szHeaders = _T("Content-Type:application/json; charset=utf-8\r\n");


hOpenHandle = InternetOpen(_T("HTTPS"), INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
if (hOpenHandle == NULL)
{
    return false;
}


hConnectHandle = InternetConnect(hOpenHandle,
    GATEWAY,
    INTERNET_DEFAULT_HTTPS_PORT,
    NULL, NULL, INTERNET_SERVICE_HTTP,
    0, 1);

if (hConnectHandle == NULL)
{
    InternetCloseHandle(hOpenHandle);
    return false;
}


hResourceHandle = HttpOpenRequest(hConnectHandle,
    _T("POST"),
    GATEWAY,
    NULL, NULL, NULL, INTERNET_FLAG_SECURE | INTERNET_FLAG_KEEP_CONNECTION,
    1);

if (hResourceHandle == NULL)
{
    InternetCloseHandle(hOpenHandle);
    InternetCloseHandle(hConnectHandle);
    return false;
}

InternetSetOption(hResourceHandle, INTERNET_OPTION_USERNAME, (LPVOID)USERNAME, _tcslen(USERNAME));
InternetSetOption(hResourceHandle, INTERNET_OPTION_PASSWORD, (LPVOID)PASSWORD, _tcslen(PASSWORD));

std::string buf;
if (HttpSendRequest(hResourceHandle, szHeaders, 0, NULL, 0))
{
    while (true)
    {
        std::string part;
        DWORD size;
        if (!InternetQueryDataAvailable(hResourceHandle, &size, 0, 0))break;
        if (size == 0)break;
        part.resize(size);
        if (!InternetReadFile(hResourceHandle, &part[0], part.size(), &size))break;
        if (size == 0)break;
        part.resize(size);
        buf.append(part);
    }
}

if (!buf.empty())
{
    // Get data back
}

InternetCloseHandle(hResourceHandle);
InternetCloseHandle(hConnectHandle);
InternetCloseHandle(hOpenHandle);

这应该在Win32 API环境中工作。

这里有一个例子。

你可以使用embeddedRest库。它是一个轻量级的头文件库。所以很容易将它包含到你的项目中，它不需要编译，因为里面没有。cpp文件。

从自述文件中请求示例。Md from repo:

#include "UrlRequest.hpp"

//...

UrlRequest request;
request.host("api.vk.com");
const auto countryId = 1;
const auto count = 1000;
request.uri("/method/database.getCities",{
    { "lang", "ru" },
    { "country_id", countryId },
    { "count", count },
    { "need_all", "1" },
});
request.addHeader("Content-Type: application/json");
auto response = std::move(request.perform());
if (response.statusCode() == 200) {
  cout << "status code = " << response.statusCode() << ", body = *" << response.body() << "*" << endl;
}else{
  cout << "status code = " << response.statusCode() << ", description = " << response.statusDescription() << endl;
}

有什么方法可以简单地用c++发出HTTP请求吗?具体来说，我想下载一个页面(一个API)的内容，并检查内容，看看它是否包含1或0。是否也可以将内容下载到字符串中?

首先……我知道这个问题已经有12年了。然而。没有一个答案给出的例子是“简单的”，不需要构建一些外部库

下面是我能想到的检索和打印网页内容的最简单的解决方案。

关于下面示例中使用的函数的一些文档

// wininet lib : https://learn.microsoft.com/en-us/windows/win32/api/wininet/ // wininet->internetopena(); https://learn.microsoft.com/en-us/windows/win32/api/wininet/nf-wininet-internetopena // wininet->intenetopenurla(); https://learn.microsoft.com/en-us/windows/win32/api/wininet/nf-wininet-internetopenurla // wininet->internetreadfile(); https://learn.microsoft.com/en-us/windows/win32/api/wininet/nf-wininet-internetreadfile // wininet->internetclosehandle(); https://learn.microsoft.com/en-us/windows/win32/api/wininet/nf-wininet-internetclosehandle

#include <iostream>

#include <WinSock2.h>
#include <wininet.h>
#pragma comment(lib, "wininet.lib")

int main()
{
    //  ESTABLISH SOME LOOSE VARIABLES
    const int size = 4096;
    char buf[size];
    DWORD length;

    //  ESTABLISH CONNECTION TO THE INTERNET
    HINTERNET internet = InternetOpenA("Mozilla/5.0", INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, NULL);
    if (!internet)
        ExitProcess(EXIT_FAILURE);  //  Failed to establish connection to internet, Exit

    //  ATTEMPT TO CONNECT TO WEBSITE "google.com"
    HINTERNET response = InternetOpenUrlA(internet, "http://www.google.com", NULL, NULL, NULL, NULL);
    if (!response) {
        //  CONNECTION TO "google.com" FAILED
        InternetCloseHandle(internet);  //  Close handle to internet
        ExitProcess(EXIT_FAILURE);
    }

    //  READ CONTENTS OF WEBPAGE IN HTML FORMAT
    if (!InternetReadFile(response, buf, size, &length)) {     
        //  FAILED TO READ CONTENTS OF WEBPAGE
        //  Close handles and Exit
        InternetCloseHandle(response);                      //  Close handle to response
        InternetCloseHandle(internet);                      //  Close handle to internet
        ExitProcess(EXIT_FAILURE);
    }
    
    //  CLOSE HANDLES AND OUTPUT CONTENTS OF WEBPAGE
    InternetCloseHandle(response);                      //  Close handle to response
    InternetCloseHandle(internet);                      //  Close handle to internet
    std::cout << buf << std::endl;
    return 0;
}