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。