HTTP服务器上断点下载文件

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从HTTP服务器上下载一个文件有很多方法，“热心”的微软提供了 WinInet 类，用起来也很方便。当然，我们也可以自己实现这些功能，通过格式化请求头很容易就能实现断点续传和检查更新等等功能。

连接主机
格式化请求头
设置接收,发送超时

要想从服务器下载文件，首先要向服务器发送一个请求。HTTP 请求头由若干行字符串组成。下面结合实例说说 HTTP 请求头的格式。假设要下载 http://www.sina.com.cn/index.html 这个网页，那么请求头的写法如下：

第1行：方法，请求的内容，HTTP协议的版本
下载一般可以用GET方法，请求的内容是“/index.html”，HTTP协议的版本是指浏览器支持的版本，对于下载软件来说无所谓，所以用1.1版 “HTTP/1.1”；
“GET /index.html HTTP/1.1”

第2行：主机名，格式为“Host:主机”
在这个例子中是：“Host:www.sina.com.cn”

第3行：接受的数据类型，下载软件当然要接收所有的数据类型，所以：
“Accept:*/*”

第4行：指定浏览器的类型
有些服务器会根据客户服务器种类的不同会增加或减少一些内容，在这个例子中可以这样写：

“User-Agent:Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)”

第5行：连接设置
设定为一直保持连接：“Connection:Keep-Alive”

第6行：若要实现断点续传则要指定从什么位置起接收数据，格式如下：

“Range: bytes=起始位置 - 终止位置”

比如要读前500个字节可以这样写：“Range: bytes=0 - 499”；从第 1000 个字节起开始下载：

“Range: bytes=999 -”

最后，别忘了加上一行空行，表示请求头结束。整个请求头如下：

GET /index.html HTTP/1.1
Host:www.sina.com.cn
Accept:*/*
User-Agent:Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)
Connection:Keep-Alive
下面用例子看看如何进行断点的下载吧






// DownloadFile.h: interface for the CDownloadFile class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_DOWNLOADFILE_H__E9A59779_BEF9_4A78_8D0E_ED8C9498E07C__INCLUDED_)
#define AFX_DOWNLOADFILE_H__E9A59779_BEF9_4A78_8D0E_ED8C9498E07C__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#define NOTIFY_MSG_WPARAM_GENDOWNFILEID                0x01

#define NOTIFY_MSG_LOW_WPARAM_FULLSIZE                0x10
#define NOTIFY_MSG_LOW_WPARAM_CURRENTSIZE            0x20
#define NOTIFY_MSG_LOW_WPARAM_DOWNSIZE                0x30
#define NOTIFY_MSG_LOW_WPARAM_DOWNSPEED                0x40

class CDownloadFile  
{
public:
    BOOL OpenRedirectHttpURL(CString &strOldLocation,CInternetSession &cSession);
    BOOL DownLoadFile(LPCTSTR lpFileURL,LPCTSTR lpSaveFile);
    CDownloadFile();
    virtual ~CDownloadFile();
    LPCTSTR GetSavedFileName() { return m_strSaveToFile;}
    LPCTSTR GetDownURL() { return m_strFileURL;}

public:
    WORD GenFileID();
    void RegisterNotifyWindow(DWORD dwThreadID,HWND hWnd,DWORD dwMsg);
    BOOL GetUNCFile();
    bool m_bForceReload;
    DWORD m_TimeOut;
    WORD m_wFileID;

protected:
    DWORD m_dwThreadID;
    void PostNotifyMessage(WPARAM wParam, LPARAM lParam);
    DWORD m_dwMsgID;
    HWND m_hNotify;
    BOOL GetFtpFile(CInternetSession &cSession);
    BOOL GetHttpFile(CInternetSession &cSession);
    CString m_strTmpFileName;
    CString m_strFileURL;
    CString m_strSaveToFile;
    CString    m_rawHeaders;
    float  m_transferRate;
    DWORD    m_infoStatusCode;
};

#endif // !defined(AFX_DOWNLOADFILE_H__E9A59779_BEF9_4A78_8D0E_ED8C9498E07C__INCLUDED_)


// DownloadFile.cpp: implementation of the CDownloadFile class.
//
//////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "DownloadFile.h"

#pragma comment( lib,"Wininet.lib" )

#include "shlwapi.h"
#pragma comment( lib,"shlwapi.lib" )

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

#define BUFFER_SIZE 4095

const TCHAR szHeaders[] = _T("Accept: */*/r/nUser-Agent:  Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)/r/n");

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
//////////////////////////////////////////////////////////////////////

CDownloadFile::CDownloadFile()
{
    m_TimeOut = 0;
    m_bForceReload = true;
    m_dwThreadID = 0;
    m_hNotify = NULL;
    m_dwMsgID = 0;
    m_wFileID = 0;
}

CDownloadFile::~CDownloadFile()
{

}

BOOL CDownloadFile::DownLoadFile(LPCTSTR lpFileURL, LPCTSTR lpSaveFile)
{
    BOOL bRet = FALSE;
    if ( !::PathIsURL(lpFileURL) )
    {
        return bRet;
    }
    m_strSaveToFile = lpSaveFile;
    m_strFileURL = lpFileURL;
    m_strTmpFileName = lpSaveFile;
    m_strTmpFileName += _T(".df!");
    CString strServer,strObject;INTERNET_PORT nPort;
    CString strAgentCaption =  _T("Update Download ") ;
    strAgentCaption += ::PathFindFileName(lpSaveFile);
    DWORD dwFlags = 0;
    InternetGetConnectedState(&dwFlags, 0);
    CInternetSession session (strAgentCaption, 1,
        (dwFlags & INTERNET_CONNECTION_PROXY) == INTERNET_CONNECTION_PROXY ? INTERNET_OPEN_TYPE_PRECONFIG : INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY,
        NULL, NULL, 0);
    AfxParseURL(m_strFileURL,dwFlags,strServer,strObject,nPort);

    if (m_TimeOut != 0)
        session.SetOption(INTERNET_OPTION_DATA_RECEIVE_TIMEOUT, m_TimeOut);
    if( !m_wFileID )
        m_wFileID = GenFileID();
    PostNotifyMessage(NOTIFY_MSG_WPARAM_GENDOWNFILEID,m_wFileID);

    try
    {
        if ( dwFlags== AFX_INET_SERVICE_HTTP )
        {
            bRet = GetHttpFile(session);
        }
        else if( dwFlags== AFX_INET_SERVICE_FTP )
        {
            bRet = GetFtpFile(session);
        }
        else if( dwFlags== AFX_INET_SERVICE_FILE )
        {
            if( UrlIsFileUrl(m_strFileURL) )
                bRet = GetUNCFile();
        }
        else
        {
            ;
        }    
    }
    catch (CException* pEx)
    {
        TCHAR szErrorMsg[MAX_PATH] = {0};
        pEx->GetErrorMessage(szErrorMsg, MAX_PATH);
        TRACE( _T("Exception: %s/n") , szErrorMsg);
        pEx->Delete();
    }

    session.Close();
    m_wFileID = 0;
    if (bRet)
    {
        if (!::MoveFileEx(m_strTmpFileName,m_strSaveToFile,MOVEFILE_REPLACE_EXISTING) )
        {
            Sleep(1000);
            ::MoveFileEx(m_strTmpFileName,m_strSaveToFile,MOVEFILE_REPLACE_EXISTING);
        }
    }
    return bRet;
}

BOOL CDownloadFile::GetHttpFile(CInternetSession &cSession)
{
    BOOL bRet = FALSE;
    CFile m_TmpFile;
    CFileException fileException;
    
    if ( !m_TmpFile.Open (m_strTmpFileName, 
        CFile::modeCreate | CFile::modeNoTruncate  | CFile::modeReadWrite
        | CFile::shareDenyWrite    | CFile::typeBinary,
        &fileException ) )
    {
        TRACE( _T("Open File failed: %d/n"), fileException.m_cause );
        return bRet;
    }
    CString strRangeQuest;

    if (m_TmpFile.GetLength()>0)
    {
        PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_CURRENTSIZE,m_wFileID),m_TmpFile.GetLength());
        m_TmpFile.SeekToEnd();
        strRangeQuest.Format( _T("%sRange: bytes=%d-/r/n"), szHeaders,m_TmpFile.GetLength());
    }
    else
        strRangeQuest = szHeaders;

    DWORD dwCount = 0;
    CHttpFile* pFile = NULL;
    CString strTmpURL = m_strFileURL;
    try
    {
        DWORD dwFlags = INTERNET_FLAG_TRANSFER_BINARY 
            |INTERNET_FLAG_DONT_CACHE
            |INTERNET_FLAG_PRAGMA_NOCACHE
            ;
        if (m_bForceReload) {
            dwFlags |= INTERNET_FLAG_RELOAD;
        }
        //Here Find URLFile Redirect.
//        OpenRedirectHttpURL(strTmpURL,cSession);
        pFile = (CHttpFile*) cSession.OpenURL(strTmpURL, 1, dwFlags,strRangeQuest, -1);
    }
    catch (CInternetException* e)
    {
        TCHAR   szCause[MAX_PATH] = {0};
        e->GetErrorMessage(szCause, MAX_PATH);
        e->Delete();
        delete pFile;
        pFile = NULL;
        return bRet;
    }
    
    COleDateTime startTime = COleDateTime::GetCurrentTime();
    DWORD dwHttpFileSize = 0;
    if (pFile)
    {
        BYTE buffer[BUFFER_SIZE+1] = {0};
        try {
            UINT nRead = 0;
            pFile->QueryInfo(HTTP_QUERY_CONTENT_LENGTH | HTTP_QUERY_FLAG_NUMBER,dwHttpFileSize);
            PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_FULLSIZE,m_wFileID),dwHttpFileSize);
            TRACE( _T("Totoal Length is %d/n"), dwHttpFileSize );
            dwCount = 0;
            do
            {
                nRead = pFile->Read(buffer, BUFFER_SIZE);
                if (nRead > 0)
                {
                    buffer[nRead] = 0;
                    m_TmpFile.Write(buffer,nRead);
                    
                    COleDateTimeSpan elapsed = COleDateTime::GetCurrentTime() - startTime;
                    double dSecs = elapsed.GetTotalSeconds();
                    PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSIZE,m_wFileID),dwCount);
                    if (dSecs > 0.0)
                    {
                        dwCount += nRead;
                        m_transferRate = (float) ( dwCount / 1024.0 / dSecs );
                        TRACE("Read %d bytes (%0.1f Kb/s)/n", dwCount, m_transferRate );
                    }
                    else
                    {
                        TRACE("Read %d bytes/n", dwCount);
                        m_transferRate = (float) ( dwCount / 1024.0 );
                    }
                    PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSPEED,m_wFileID),(LPARAM)m_transferRate);
                }
            }
            while (nRead > 0);
            bRet = TRUE;
        }
        catch (CFileException *e)
        {
            TCHAR   szCause[MAX_PATH] = {0};
            e->GetErrorMessage(szCause, MAX_PATH);
            TRACE("ErrorMsg : %s/n", szCause);
            e->Delete();
            delete pFile;
            m_TmpFile.Close();
            return FALSE;
        }
        pFile->QueryInfoStatusCode(m_infoStatusCode);       
        pFile->QueryInfo(HTTP_QUERY_RAW_HEADERS ,m_rawHeaders);
        pFile->Close();
        m_TmpFile.Close();
        delete pFile;
    }
    
    return bRet;
}

BOOL CDownloadFile::OpenRedirectHttpURL(CString &strOldLocation,CInternetSession &cSession)
{
    BOOL bRet = FALSE;
    CHttpFile *pFile = NULL;
    CHttpConnection* pServer = NULL;
    CString strServerName,strObject;
    INTERNET_PORT nPort = 0;
    DWORD dwServiceType = 0;
    
    if (!AfxParseURL(strOldLocation, dwServiceType, strServerName, strObject, nPort) ||
        dwServiceType != INTERNET_SERVICE_HTTP)
    {
        TRACE( _T("Not A Http Quest!/n") );
        return bRet;
    }
    
    pServer = cSession.GetHttpConnection(strServerName, nPort);
    
    pFile = pServer->OpenRequest(CHttpConnection::HTTP_VERB_GET,
        strObject, NULL, 1, NULL, NULL, 
        INTERNET_FLAG_EXISTING_CONNECT | INTERNET_FLAG_NO_AUTO_REDIRECT);
    pFile->AddRequestHeaders(szHeaders);
    pFile->SendRequest();
    
    DWORD dwRet;
    pFile->QueryInfoStatusCode(dwRet);
    
    // if access was denied, prompt the user for the password
    
    if (dwRet == HTTP_STATUS_DENIED)
    {
        DWORD dwPrompt;
        dwPrompt = pFile->ErrorDlg(NULL, ERROR_INTERNET_INCORRECT_PASSWORD,
            FLAGS_ERROR_UI_FLAGS_GENERATE_DATA | FLAGS_ERROR_UI_FLAGS_CHANGE_OPTIONS, NULL);
        
        // if the user cancelled the dialog, bail out
        
        if (dwPrompt != ERROR_INTERNET_FORCE_RETRY)
        {
            TRACE( _T("Access denied: Invalid password/n") );
            // close up the redirected site

            pFile->Close();
            delete pFile;
            pServer->Close();
            delete pServer;

            return bRet;
        }
        
        pFile->SendRequest();
        pFile->QueryInfoStatusCode(dwRet);
    }
        
    // were we redirected?
    // these response status codes come from WININET.H
    
    if (dwRet == HTTP_STATUS_MOVED ||
        dwRet == HTTP_STATUS_REDIRECT ||
        dwRet == HTTP_STATUS_REDIRECT_METHOD)
    {
        CString strNewLocation;
        pFile->QueryInfo(HTTP_QUERY_RAW_HEADERS_CRLF, strNewLocation);
        int nPlace = strNewLocation.Find(_T("Location: "));
        if (nPlace == -1)
        {
            TRACE( _T("Error: Site redirects with no new location/n") );
            // close up the redirected site

            pFile->Close();
            delete pFile;
            pServer->Close();
            delete pServer;
            return bRet;
        }    
        strNewLocation = strNewLocation.Mid(nPlace + 10);
        nPlace = strNewLocation.Find('/n');
        if (nPlace > 0)
            strNewLocation = strNewLocation.Left(nPlace);
        strOldLocation = strNewLocation;
    }
    if ( dwRet == HTTP_STATUS_OK )
    {
        bRet = TRUE;
    }
    // close up the redirected site
    pFile->Close();
    delete pFile;
    pServer->Close();
    delete pServer;

    return bRet;
}

BOOL CDownloadFile::GetFtpFile(CInternetSession &cSession)
{
    BOOL bRet = FALSE;
    CFile m_TmpFile;
    CFileException fileException;
    
    if ( !m_TmpFile.Open (m_strTmpFileName, 
        CFile::modeCreate | CFile::modeNoTruncate  | CFile::modeReadWrite
        | CFile::shareDenyWrite    | CFile::typeBinary,
        &fileException ) )
    {
        TRACE( _T("Open File failed: %d/n"), fileException.m_cause );
        return bRet;
    }

    DWORD dwCount = 0;
    CFtpConnection *pFtpConn = NULL;
    CInternetFile *pFile = NULL;
    try
    {
        CString strServerName,strObject,strUserName,strPassword;
        INTERNET_PORT nPort = 0;
        DWORD dwServiceType = 0;
        CString strRestPointCommand;
    
        if (!AfxParseURLEx(m_strFileURL, dwServiceType, strServerName, strObject, nPort, 
            strUserName, strPassword) ||
            dwServiceType != INTERNET_SERVICE_FTP)
        {
            TRACE( _T("Not A Ftp Quest!/n") );
        }
        // CFtpConnection ERROR_INTERNET_NO_DIRECT_ACCESS CInternetSession
        if (strUserName.IsEmpty())
            pFtpConn = cSession.GetFtpConnection(strServerName,NULL,NULL,nPort,m_bForceReload);
        else
            pFtpConn = cSession.GetFtpConnection(strServerName,strUserName,strPassword,nPort,m_bForceReload);
        if (m_TmpFile.GetLength())
        {
            PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_CURRENTSIZE,m_wFileID),m_TmpFile.GetLength());
            m_TmpFile.SeekToEnd();
            strRestPointCommand.Format( _T("REST %d"), m_TmpFile.GetLength());
            //strRestPointCommand.Format( _T("ls") );
            if ( !FtpCommand((*pFtpConn), FALSE, FTP_TRANSFER_TYPE_ASCII, 
            strRestPointCommand, 0, 0) )
            {
                TRACE( _T("FtpCommand failed, error: %d/n"), GetLastError());
                m_TmpFile.SeekToBegin();
            }    
        }
        if (pFtpConn)
        {
            pFile = pFtpConn->OpenFile(strObject);
        }
    }
    catch (CInternetException* e)
    {
        TCHAR   szCause[MAX_PATH] = {0};
        e->GetErrorMessage(szCause, MAX_PATH);
        e->Delete();
        delete pFile;
        delete pFtpConn;
        return bRet;
    }
    
    COleDateTime startTime = COleDateTime::GetCurrentTime();
    DWORD dwFtpFileSize = 0;
    if (pFile)
    {
        BYTE buffer[BUFFER_SIZE+1] = {0};
        try {
            UINT nRead = 0;
            dwFtpFileSize = FtpGetFileSize( (*pFile),0);
            PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_FULLSIZE,m_wFileID),dwFtpFileSize);
            TRACE( _T("Totoal Length is %d/n"), dwFtpFileSize );
            dwCount = 0;
            do
            {
                nRead = pFile->Read(buffer, BUFFER_SIZE);
                if (nRead > 0)
                {
                    buffer[nRead] = 0;
                    m_TmpFile.Write(buffer,nRead);
                    
                    COleDateTimeSpan elapsed = COleDateTime::GetCurrentTime() - startTime;
                    double dSecs = elapsed.GetTotalSeconds();
                    PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSIZE,m_wFileID),dwCount);
                    if (dSecs > 0.0)
                    {
                        dwCount += nRead;
                        m_transferRate = (float)(dwCount / 1024.0 / dSecs);
                        TRACE("Read %d bytes (%0.1f Kb/s)/n", dwCount, m_transferRate );                    
                    }
                    else
                    {
                        TRACE("Read %d bytes/n", dwCount);
                        m_transferRate = (float)(dwCount / 1024.0);
                    }
                    PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSPEED,m_wFileID),(LPARAM)m_transferRate);
                }
            }
            while (nRead > 0);
            bRet = TRUE;
        }
        catch (CFileException *e)
        {
            TCHAR   szCause[MAX_PATH] = {0};
            e->GetErrorMessage(szCause, MAX_PATH);
            TRACE("ErrorMsg : %s/n", szCause);
            e->Delete();
            delete pFile;
            pFtpConn->Close();
            delete pFtpConn;
            m_TmpFile.Close();
            return FALSE;
        }
        pFile->Close();
        delete pFile;
        m_TmpFile.Close();
        pFtpConn->Close();
        delete pFtpConn;
    }
    return bRet;
}

BOOL CDownloadFile::GetUNCFile()
{
    BOOL bRet = FALSE;
    CFile m_TmpFile,m_SrcFile;
    CFileException fileException;
    CString strOldLocation = m_strFileURL;
    if ( !m_TmpFile.Open (m_strTmpFileName, 
        CFile::modeCreate | CFile::modeNoTruncate  | CFile::modeReadWrite
        | CFile::shareDenyWrite    | CFile::typeBinary,
        &fileException ) )
    {
        TRACE( _T("Open File failed: %d/n"), fileException.m_cause );
        return bRet;
    }
    strOldLocation.TrimLeft();
    strOldLocation.TrimRight();
    if( StrCmpNI(strOldLocation, _T("file:/"),6) == 0 )
    {
        strOldLocation = strOldLocation.Mid(8);
        strOldLocation.Replace( _T('/'), _T('//'));
    }

    if ( !m_SrcFile.Open ( strOldLocation, 
         CFile::modeRead | CFile::shareDenyWrite | CFile::typeBinary,
        &fileException ) )
    {
        TRACE( _T("Open File failed: %d/n"), fileException.m_cause );
        return bRet;
    }
    COleDateTime startTime = COleDateTime::GetCurrentTime();
    DWORD dwCount = 0;
    try {
        if (m_TmpFile.GetLength())
        {
            PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_CURRENTSIZE,m_wFileID),m_TmpFile.GetLength());
            m_TmpFile.SeekToEnd();
            m_SrcFile.Seek(m_TmpFile.GetLength(), CFile::begin);
        }
        BYTE buffer[BUFFER_SIZE+1] = {0};
        UINT nRead = 0;
        PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_FULLSIZE,m_wFileID),m_SrcFile.GetLength());
        TRACE( _T("Totoal Length is %d,left is %d/n"), m_SrcFile.GetLength() ,m_SrcFile.GetLength() - m_TmpFile.GetLength());
        dwCount = 0;
        do
        {
            nRead = m_SrcFile.Read(buffer, BUFFER_SIZE);
            if (nRead > 0)
            {
                buffer[nRead] = 0;
                m_TmpFile.Write(buffer,nRead);
                
                COleDateTimeSpan elapsed = COleDateTime::GetCurrentTime() - startTime;
                double dSecs = elapsed.GetTotalSeconds();
                PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSIZE,m_wFileID),dwCount);
                if (dSecs > 0.0)
                {
                    dwCount += nRead;
                    m_transferRate = (float)(dwCount / 1024.0 / dSecs);
                    TRACE("Read %d bytes (%0.1f Kb/s)/n", dwCount, m_transferRate );                    
                }
                else
                {
                    TRACE("Read %d bytes/n", dwCount);
                    m_transferRate = (float)(dwCount / 1024.0);
                }
                PostNotifyMessage(MAKEWPARAM(NOTIFY_MSG_LOW_WPARAM_DOWNSPEED,m_wFileID),(LPARAM)m_transferRate);
            }
        }
        while (nRead > 0);
        bRet = TRUE;
    }
    catch (CFileException *e)
    {
        TCHAR   szCause[MAX_PATH] = {0};
        e->GetErrorMessage(szCause, MAX_PATH);
        TRACE("ErrorMsg : %s/n", szCause);
        e->Delete();
        m_TmpFile.Close();
        return FALSE;
    }
    m_TmpFile.Close();
    return bRet;
}

void CDownloadFile::RegisterNotifyWindow(DWORD dwThreadID,HWND hWnd, DWORD dwMsg)
{
    m_dwThreadID = dwThreadID;
    m_hNotify = hWnd;
    m_dwMsgID = dwMsg;
}

void CDownloadFile::PostNotifyMessage(WPARAM wParam, LPARAM lParam)
{
    if (m_hNotify)
    {
        ::PostMessage(m_hNotify, m_dwMsgID, wParam,  lParam);
    }
    if ( m_dwThreadID )
    {
        ::PostThreadMessage(m_dwThreadID,m_dwMsgID, wParam, lParam);
    }
}

WORD CDownloadFile::GenFileID()
{
    srand(GetTickCount());
    return rand() & 0xFFFF;
}

UINT ThreadDownSingleFile( LPVOID pParam )
{
    CDownloadFile m_DownFile;
    UINT uRet = 0;
    if (lpDownParam)
    {
        m_DownFile.m_wFileID = m_DownFile.GenFileID();
        //这里注册通知窗口和消息
        //m_DownFile.RegisterNotifyWindow
        if ( m_DownFile.DownLoadFile(m_Msg.lpFileSrc, m_Msg.lpFileDst) )
        {
            uRet = 1;
        }
    }
    return uRet;
}

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