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。