qt 使用 winhttp POST https demo

以下是使用 Qt 的 WinHTTP 发送 POST 请求的示例代码：

#include <Windows.h>
#include <Winhttp.h>
#include <QDebug>

#pragma comment(lib, "Winhttp.lib")

void sendRequest()
{
    // 打开一个会话句柄
    HINTERNET hSession = WinHttpOpen(L"WinHTTP Example/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);

    if (!hSession) {
        qWarning() << "WinHttpOpen failed: " << GetLastError();
        return;
    }

    // 连接服务器
    HINTERNET hConnect = WinHttpConnect(hSession, L"www.example.com", INTERNET_DEFAULT_HTTPS_PORT, 0);

    if (!hConnect) {
        qWarning() << "WinHttpConnect failed: " << GetLastError();
        WinHttpCloseHandle(hSession);
        return;
    }

    // 创建一个请求句柄
    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"POST", L"/api", NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE);

    if (!hRequest) {
        qWarning() << "WinHttpOpenRequest failed: " << GetLastError();
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return;
    }

    // 设置请求头
    LPCWSTR headers = L"Content-Type: application/json\r\n";
    BOOL bResults = WinHttpAddRequestHeaders(hRequest, headers, (ULONG)wcslen(headers), WINHTTP_ADDREQ_FLAG_ADD);

    if (!bResults) {
        qWarning() << "WinHttpAddRequestHeaders failed: " << GetLastError();
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return;
    }

    // 设置请求体
    LPCWSTR data = L"{\"name\":\"example\",\"age\":18}";
    bResults = WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, (LPVOID)data, (DWORD)wcslen(data) * sizeof(WCHAR), (DWORD)wcslen(data) * sizeof(WCHAR), 0);

    if (!bResults) {
        qWarning() << "WinHttpSendRequest failed: " << GetLastError();
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return;
    }

    // 发送请求
    bResults = WinHttpReceiveResponse(hRequest, NULL);

    if (!bResults) {
        qWarning() << "WinHttpReceiveResponse failed: " << GetLastError();
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return;
    }

    // 读取响应体
    DWORD dwSize = 0;
    DWORD dwDownloaded = 0;
    LPSTR pszOutBuffer;
    std::string strResponse;

    do {
        // 获取响应体的大小
        dwSize = 0;
        if (!WinHttpQueryDataAvailable(hRequest, &dwSize)) {
            qWarning() << "WinHttpQueryDataAvailable failed: " << GetLastError();
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return;
        }

        // 分配缓存
        pszOutBuffer = new char[dwSize + 1];
        if (!pszOutBuffer) {
            qWarning() << "Out of memory";
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return;
        }

        // 读取响应体
        ZeroMemory(pszOutBuffer, dwSize + 1);
        if (!WinHttpReadData(hRequest, (LPVOID)pszOutBuffer, dwSize, &dwDownloaded)) {
            qWarning() << "WinHttpReadData failed: " << GetLastError();
            delete[] pszOutBuffer;
            WinHttpCloseHandle(hRequest);
            WinHttpCloseHandle(hConnect);
            WinHttpCloseHandle(hSession);
            return;
        }

        // 添加到响应字符串中
        strResponse.append(pszOutBuffer, dwDownloaded);
        delete[] pszOutBuffer;

    } while (dwSize > 0);

    // 输出响应字符串
    qDebug() << QString::fromStdString(strResponse);

    // 关闭句柄
    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);
}

在上面的代码中，我们使用 WinHTTP 库发送了一个 HTTPS POST 请求，请求体为 JSON 格式的数据。你需要根据实际情况修改以下参数：

- `L"www.example.com"`：服务器域名或 IP 地址。
- `L"/api"`：请求的 API 路径。
- `L"Content-Type: application/json\r\n"`：请求头中的内容类型，根据实际情况修改。
- `L"{\"name\":\"example\",\"age\":18}"`：请求体的内容，根据实际情况修改。