写一个c/c++ 使用wininet库向www.baidu.com发送HTTP POST/GET请求的代码

在C/C++中使用WinINET库（Windows Internet Network Library）发送HTTP GET或POST请求通常涉及到`INTERNETCOMMUNICATOR`结构、`INTERNETCONNECT`函数以及`INTERNETREQUEST`等API。这里给出一个简单的示例，展示如何发送GET和POST请求到www.baidu.com：

#include <windows.h>
#include <wininet.h>

// 发送GET请求
void send_GET_request(LPCSTR url) {
    HINTERNET hSession = NULL;
    HINTERNET hConnect = NULL;
    HINTERNET hRequest = NULL;

    // 初始化WinINET
    hSession = InternetOpen(NULL, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
    
    if (hSession) {
        // 连接到服务器
        hConnect = InternetConnect(hSession, url, INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, 0, 0, 0);
        
        if (hConnect) {
            // 创建请求
            hRequest = HttpOpenRequest(hConnect, _T("GET"), url, NULL, NULL, _T("HTTP/1.1"), INTERNET_FLAG_RELOAD | INTERNET_FLAG_NO_CACHE_WRITE, NULL);

            if (hRequest) {
                // 发起请求并接收响应
                DWORD dwResponse = 0;
                char szBuffer[4096];
                if (HttpSendRequest(hRequest, NULL, 0, NULL, 0, szBuffer, sizeof(szBuffer), &dwResponse)) {
                    printf("GET Response:\n%s\n", szBuffer);
                }
                InternetCloseHandle(hRequest);
            }
            InternetCloseHandle(hConnect);
        }
        InternetCloseHandle(hSession);
    } else {
        printf("Error initializing WinINET: %d\n", GetLastError());
    }
}

// 发送POST请求，这里仅做示例，实际应用需要处理POST数据
void send_POST_request(LPCSTR url, LPCSTR postData) {
    HINTERNET hSession, hConnect, hRequest;

    hSession = InternetOpen(NULL, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
    hConnect = InternetConnect(hSession, url, INTERNET_DEFAULT_HTTP_PORT, NULL, NULL, 0, 0, 0);

    if (hConnect) {
        hRequest = HttpOpenRequest(hConnect, _T("POST"), url, NULL, NULL, _T("HTTP/1.1"), INTERNET_FLAG_RELOAD | INTERNET_FLAG_NO_CACHE_WRITE, NULL);

        if (hRequest) {
            LPCTSTR lpPostData = postData;
            DWORD dwContentLength = lstrlen(lpPostData);
            DWORD dwIndex = 0;
            const char* boundary = "--WebKitFormBoundary7MA4YWxkTrZu0gW"; // 示例中的边界值

            // 添加请求头
            HttpAddRequestHeader(hRequest, _T("Content-Type"), _T("multipart/form-data; boundary=") + boundary, -1);

            // 发送POST数据
            while (dwIndex < dwContentLength) {
                HttpSendRequestChunk(hRequest, boundary, strlen(boundary), lpPostData + dwIndex, 1);
                dwIndex += strlen(lpPostData) + 1;
            }

            // 结束POST数据
            HttpSendRequestChunk(hRequest, "\r\n--\r\n", -1, NULL, 0);

            // 接收响应
            DWORD dwResponse = 0;
            char szBuffer[4096];
            if (HttpSendRequest(hRequest, NULL, 0, NULL, 0, szBuffer, sizeof(szBuffer), &dwResponse)) {
                printf("POST Response:\n%s\n", szBuffer);
            }
            InternetCloseHandle(hRequest);
        }
        InternetCloseHandle(hConnect);
    }
    InternetCloseHandle(hSession);
}

int main() {
    send_GET_request("http://www.baidu.com");
    send_POST_request("http://www.baidu.com", "Your data here"); // 替换为实际的POST数据

    return 0;
}

注意这只是一个基本示例，并未包含错误处理和完整的POST数据处理。在实际项目中，你需要处理更多的细节，比如添加用户认证信息、设置超时、解析响应内容等。