如何在C/C++中使用WinHTTP下载文件？

//Variables 
DWORD dwSize = 0;
DWORD dwDownloaded = 0;
LPSTR pszOutBuffer;
vector <string>  vFileContent;
BOOL  bResults = FALSE;
HINTERNET  hSession = NULL,hConnect = NULL,hRequest = NULL;

// Use WinHttpOpen to obtain a session handle.
hSession = WinHttpOpen( L"WinHTTP Example/1.0",WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,WINHTTP_NO_PROXY_NAME,WINHTTP_NO_PROXY_BYPASS,0);

// Specify an HTTP server.
if (hSession)
    hConnect = WinHttpConnect( hSession,L"nytimes.com",INTERNET_DEFAULT_HTTP_PORT,0);

// Create an HTTP request handle.
if (hConnect)
    hRequest = WinHttpOpenRequest( hConnect,L"GET",L"/ref/multimedia/podcasts.html",NULL,WINHTTP_NO_REFERER,NULL);

// Send a request.
if (hRequest)
    bResults = WinHttpSendRequest( hRequest,WINHTTP_NO_ADDITIONAL_HEADERS,WINHTTP_NO_REQUEST_DATA,0);


// End the request.
if (bResults)
    bResults = WinHttpReceiveResponse( hRequest,NULL);

// Keep checking for data until there is nothing left.
if (bResults)
    do 
    {

        // Check for available data.
        dwSize = 0;
        if (!WinHttpQueryDataAvailable( hRequest,&dwSize))
            printf( "Error %u in WinHttpQueryDataAvailable.n",GetLastError());

        // Allocate space for the buffer.
        pszOutBuffer = new char[dwSize+1];
        if (!pszOutBuffer)
        {
            printf("Out of memoryn");
            dwSize=0;
        }
        else
        {
            // Read the Data.
            ZeroMemory(pszOutBuffer,dwSize+1);

            if (!WinHttpReadData( hRequest,(LPVOID)pszOutBuffer,dwSize,&dwDownloaded))
            {
                printf( "Error %u in WinHttpReadData.n",GetLastError());
            }
            else
            {
                        printf("%s",pszOutBuffer);
                            // Data in vFileContent
                vFileContent.push_back(pszOutBuffer);
            }

            // Free the memory allocated to the buffer.
            delete [] pszOutBuffer;
        }

    } while (dwSize>0);


// Report any errors.
if (!bResults)
    printf("Error %d has occurred.n",GetLastError());

// Close any open handles.
if (hRequest) WinHttpCloseHandle(hRequest);
if (hConnect) WinHttpCloseHandle(hConnect);
if (hSession) WinHttpCloseHandle(hSession);

// Write vFileContent to file
ofstream out("test.txt",ios::binary);
for (int i = 0; i < (int) vFileContent.size();i++)
out << vFileContent[i];
out.close();

当我尝试下载图片时,我只得到文件的第一行,没有错误信息.问题似乎与WinHttpOpenRequest函数中的此参数(ppwszAcceptTypes)有关.

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