C++ WinHttp连接超时设置方法

在C++中，使用WinHttp库进行HTTP请求时，可以通过设置WINHTTP_OPTION_CONNECT_TIMEOUT和WINHTTP_OPTION_RECEIVE_TIMEOUT选项来控制连接超时和接收数据超时。

以下是一个简单的示例，展示了如何设置这些超时选项：

#include<iostream>
#include<Windows.h>
#include <winhttp.h>

int main() {
    // 初始化WinHttp
    HINTERNET hSession = WinHttpOpen(L"MyUserAgent", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
    if (!hSession) {
        std::cerr << "Error: WinHttpOpen failed."<< std::endl;
        return 1;
    }

    // 设置连接超时（毫秒）
    DWORD connectTimeout = 5000; // 5 seconds
    if (!WinHttpSetOption(hSession, WINHTTP_OPTION_CONNECT_TIMEOUT, &connectTimeout, sizeof(connectTimeout))) {
        std::cerr << "Error: WinHttpSetOption (WINHTTP_OPTION_CONNECT_TIMEOUT) failed."<< std::endl;
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 设置接收数据超时（毫秒）
    DWORD receiveTimeout = 10000; // 10 seconds
    if (!WinHttpSetOption(hSession, WINHTTP_OPTION_RECEIVE_TIMEOUT, &receiveTimeout, sizeof(receiveTimeout))) {
        std::cerr << "Error: WinHttpSetOption (WINHTTP_OPTION_RECEIVE_TIMEOUT) failed."<< std::endl;
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 创建连接
    HINTERNET hConnect = WinHttpConnect(hSession, L"example.com", INTERNET_DEFAULT_HTTPS_PORT, 0);
    if (!hConnect) {
        std::cerr << "Error: WinHttpConnect failed."<< std::endl;
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 创建请求
    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"GET", L"/path/to/resource", NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, WINHTTP_FLAG_SECURE);
    if (!hRequest) {
        std::cerr << "Error: WinHttpOpenRequest failed."<< std::endl;
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 发送请求
    if (!WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0)) {
        std::cerr << "Error: WinHttpSendRequest failed."<< std::endl;
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 接收响应
    if (!WinHttpReceiveResponse(hRequest, NULL)) {
        std::cerr << "Error: WinHttpReceiveResponse failed."<< std::endl;
        WinHttpCloseHandle(hRequest);
        WinHttpCloseHandle(hConnect);
        WinHttpCloseHandle(hSession);
        return 1;
    }

    // 处理响应...

    // 清理资源
    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);

    return 0;
}

在这个示例中，我们首先使用WinHttpOpen函数初始化一个WinHttp会话。然后，我们使用WinHttpSetOption函数设置连接超时和接收数据超时。接下来，我们创建一个连接并打开一个请求，然后发送请求并接收响应。最后，我们关闭所有打开的句柄并返回。

注意：在实际应用程序中，你可能需要根据需要调整超时值。