用vc下载和获取远程文件大小

最新推荐文章于 2021-08-07 04:12:15 发布

原创最新推荐文章于 2021-08-07 04:12:15 发布 · 1.3k 阅读

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CC 4.0 BY-SA版权

文章标签：

#delete #null #url #file #session

本文介绍了一个使用C++进行网络编程的例子，演示了如何通过MFC（Microsoft Foundation Classes）从URL下载文件到本地磁盘的过程。具体步骤包括解析URL、建立HTTP连接、发送GET请求、接收响应并写入文件。

char m_URL[] = "http://www.baidu.com/img/logo.gif";
CString strServer,strObject;
CString szHeaders;
INTERNET_PORT nPort;

CInternetSession session("My Sesssion");
CHttpConnection * pServer = NULL;
CHttpFile * pFile = NULL;
DWORD dwRet , dwRead;
DWORD nServiceType;
char szBuff[1024*100];

if(TRUE!=AfxParseURL(m_URL,nServiceType,strServer,strObject,nPort))
{
   delete pServer;
   AfxMessageBox("URL error");
   return;
}

pServer = session.GetHttpConnection( strServer, nPort);
pFile = pServer->OpenRequest(CHttpConnection::HTTP_VERB_GET,strObject);
pFile->SendRequest();
pFile->QueryInfoStatusCode(dwRet);

if (dwRet == HTTP_STATUS_OK)
{

   memset( szBuff, 0, sizeof(szBuff));
   DWORD dwFileLen = m_size = pFile->GetLength();
   CString str;
   str.Format("filelen=%d",dwFileLen);

   AfxMessageBox(str);
   DWORD ret;
   dwRead=10;
   ret=0;
   HANDLE hFile;

hFile=CreateFile("d://p.gif",GENERIC_WRITE,FILE_SHARE_WRITE,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,NULL);

   while(dwRead>0)
   {
    dwRead=pFile->Read(szBuff,sizeof(szBuff)-1);
    WriteFile(hFile,szBuff,dwRead,&ret,NULL);
   }

CloseHandle(hFile);
}

delete pFile;
delete pServer;

session.Close();