C++ WinHttp接收大数据流的方法

在C++中，使用WinHttp库接收大数据流的方法如下：

首先，包含所需的头文件并链接到WinHttp库。

#include<iostream>#include<vector>#include<Windows.h>#include <Winhttp.h>#pragma comment(lib, "winhttp")

定义一个函数来初始化WinHttp会话、连接和请求。

HINTERNET InitializeWinHttp(const std::wstring& url) {    HINTERNET hSession = WinHttpOpen(L"MyUserAgent", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);    if (!hSession) {        return NULL;    }    URL_COMPONENTS urlComponents;    ZeroMemory(&urlComponents, sizeof(urlComponents));    urlComponents.dwStructSize = sizeof(urlComponents);    urlComponents.dwSchemeLength = -1;    urlComponents.dwHostNameLength = -1;    urlComponents.dwUrlPathLength = -1;    if (!WinHttpCrackUrl(url.c_str(), static_cast<DWORD>(url.length()), 0, &urlComponents)) {        WinHttpCloseHandle(hSession);        return NULL;    }    HINTERNET hConnect = WinHttpConnect(hSession, urlComponents.lpszHostName, urlComponents.nPort, 0);    if (!hConnect) {        WinHttpCloseHandle(hSession);        return NULL;    }    HINTERNET hRequest = WinHttpOpenRequest(hConnect, L"GET", urlComponents.lpszUrlPath, NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0);    if (!hRequest) {        WinHttpCloseHandle(hSession);        WinHttpCloseHandle(hConnect);        return NULL;    }    return hRequest;}

定义一个函数来接收大数据流。

bool ReceiveLargeDataStream(const std::wstring& url, std::vector<char>& data) {    HINTERNET hRequest = InitializeWinHttp(url);    if (!hRequest) {        return false;    }    if (!WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, WINHTTP_NO_REQUEST_DATA, 0, 0, 0)) {        WinHttpCloseHandle(hRequest);        return false;    }    if (!WinHttpReceiveResponse(hRequest, NULL)) {        WinHttpCloseHandle(hRequest);        return false;    }    DWORD dwStatusCode = 0;    DWORD dwSize = sizeof(dwStatusCode);    if (!WinHttpQueryHeaders(hRequest, WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER, NULL, &dwStatusCode, &dwSize, NULL)) {        WinHttpCloseHandle(hRequest);        return false;    }    if (dwStatusCode != HTTP_STATUS_OK) {        WinHttpCloseHandle(hRequest);        return false;    }    char buffer[4096];    DWORD dwBytesRead;    do {        if (!WinHttpReadData(hRequest, buffer, sizeof(buffer), &dwBytesRead)) {            WinHttpCloseHandle(hRequest);            return false;        }        if (dwBytesRead == 0) {            break;        }        data.insert(data.end(), buffer, buffer + dwBytesRead);    } while (true);    WinHttpCloseHandle(hRequest);    return true;}

在主函数中调用ReceiveLargeDataStream函数。

int main() {    std::wstring url = L"https://example.com/large-data-stream";    std::vector<char> data;    if (ReceiveLargeDataStream(url, data)) {        std::cout << "Received data size: "<< data.size()<< std::endl;    } else {        std::cerr << "Failed to receive data stream."<< std::endl;    }    return 0;}

这个示例将从指定的URL接收大数据流，并将其存储在std::vector<char>中。你可以根据需要修改此代码以处理接收到的数据。