C++ WinHttp連接超時設置方法

在C++中，使用WinHttp庫進行HTTP請求時，可以通過設置WINHTTP_OPTION_CONNECT_TIMEOUT和WINHTTP_OPTION_RECEIVE_TIMEOUT選項來控制連接超時和接收數據超時。

以下是一個簡單的示例，展示了如何設置這些超時選項：

#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;
    }

    // 設置連接超時（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;
    }

    // 設置接收數據超時（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;
    }

    // 創建連接
    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;
    }

    // 創建請求
    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;
    }

    // 發送請求
    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;
    }

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

    // 處理響應...

    // 清理資源
    WinHttpCloseHandle(hRequest);
    WinHttpCloseHandle(hConnect);
    WinHttpCloseHandle(hSession);

    return 0;
}

在這個示例中，我們首先使用WinHttpOpen函數初始化一個WinHttp會話。然后，我們使用WinHttpSetOption函數設置連接超時和接收數據超時。接下來，我們創建一個連接并打開一個請求，然后發送請求并接收響應。最后，我們關閉所有打開的句柄并返回。

注意：在實際應用程序中，你可能需要根據需要調整超時值。