C / C++ / MFC

void ThreadProc(void *param)
{
Copy(Source,Destination);
}
{
void CTestDlg::PathCame(const CString & FilePath)
{
//Some code here

HANDLE handle;
		handle = (HANDLE) _beginthread( ThreadProc,0,0); // create thread
		WaitForSingleObject(handle,INFINITE);
}

// helper for downloading data from http
class DownloadUrl
{
public:
	// constructor, requires the url of the resource to download
	DownloadUrl(const string& url);

	~DownloadUrl();

	// get (i.e. download) some content (into memory)
	int Get(void* buffer, int count);

	// how much of the content is already downloaded (as percentage)
	int PercentageRead();

private:
	// for PercentageRead
	DWORD m_Length;
	int m_BytesReadTotal;

	// managed pointers
	typedef auto_ptr<CInternetSession> apCInternetSession;
	typedef auto_ptr<CHttpConnection> apCHttpConnection;
	typedef auto_ptr<CHttpFile> apCHttpFile;

	// the resources will be automatically released (because they are managed pointers)
	apCInternetSession m_pInternetSession;
	apCHttpConnection m_pServer;
	apCHttpFile m_pFile;
};



DownloadUrl::DownloadUrl( const string& url )
{
	// use AfxParseURL to separate server from object
	CString server, object;
	DWORD service_type;
	INTERNET_PORT internet_port;
	AfxParseURL(url.c_str(), service_type, server, object, internet_port);
	if (server.IsEmpty() || object.IsEmpty())
		throw exception("Could not parse URL");

	// open an internet session
	m_pInternetSession = apCInternetSession(new CInternetSession("Microsoft Internet Explorer 5.0"));
	m_pInternetSession->SetOption(INTERNET_OPTION_CONNECT_TIMEOUT, 15000);
	m_pInternetSession->SetOption(INTERNET_OPTION_CONNECT_BACKOFF, 1000);
	m_pInternetSession->SetOption(INTERNET_OPTION_CONNECT_RETRIES, 2);
	m_pInternetSession->EnableStatusCallback(TRUE);

	// open a new connection to server
	m_pServer = apCHttpConnection(m_pInternetSession->GetHttpConnection(server, internet_port));
	if (m_pServer.get() == NULL)
		throw exception("HTTP connection failed");

	// make a GET request	
	m_pFile = apCHttpFile(m_pServer->OpenRequest("GET", object, NULL));
	if (m_pFile.get() == NULL)
		throw exception("Request failed");
	m_pFile->AddRequestHeaders("Accept: audio/x-aiff, audio/basic, audio/midi, audio/mpeg, audio/wav, image/jpeg, image/gif, image/jpg, image/png, image/mng, image/bmp, text/plain, text/html, text/htm\r\n");
	m_pFile->AddRequestHeaders("User-Agent: GetWebFile/1.0\r\n", HTTP_ADDREQ_FLAG_ADD_IF_NEW);
	m_pFile->SendRequest();

	// check that everything was OK
	DWORD dwStatus;	
	m_pFile->QueryInfoStatusCode(dwStatus);
	if (dwStatus != HTTP_STATUS_OK)
		throw exception("URL was denied by server");

	// query the length of the file we're getting
	m_Length = 0;
	m_pFile->QueryInfo(HTTP_QUERY_CONTENT_LENGTH, m_Length);

	m_BytesReadTotal = 0;
}

DownloadUrl::~DownloadUrl()
{

}

int DownloadUrl::Get( void* buffer, int count )
{
	UINT bytes_read = m_pFile->Read(buffer, count);
	m_BytesReadTotal += bytes_read;
	return bytes_read;
}

int DownloadUrl::PercentageRead()
{
	if (!m_Length)
		return 0;

	// what percentage of content has been downloaded?
	double ratio = m_BytesReadTotal;
	ratio /= m_Length;
	ratio *= 100;

	return (int) ratio;
}

try {
	// start connection to server
	DownloadUrl download_url("http://example.com/content.html");

	// memory buffer
	static const unsigned buffer_size = 64*1024; // 64 KB
	char buffer[buffer_size+1];

	// output file
	ofstream tmpfile("c:\\file.html", ios::out | ios::binary);

	// download the content
	while (int bytes_read = download_url.Get(buffer, buffer_size))
	{
		tmpfile.write(buffer, bytes_read);

		// show progress
	}
	
} 
// catch exceptions
catch (exception& ) {
	// do something
}

return CW2CT(fi.achName);

1. The database contains what is expectded (i.e. what is the format of the image inside the db (raw data, bitmap, jpeg,...)?).
2. Your function(s) correctly transfer on file the data retrived from the database (i.e. the binary content of the file matches the one of the record in the database).