http 下载

来源：互联网发布：mac 环境变量配置方法编辑：程序博客网时间：2024/05/02 04:27

visual c++网络通讯编程实用案例精选中

DWORD dwFlags;
InternetGetConnectedState(&dwFlags, 0);
CHAR strAgent[64];
sprintf(strAgent, "Agent%ld", timeGetTime());
HINTERNET hOpen;
if(!(dwFlags & INTERNET_CONNECTION_PROXY))
  hOpen = InternetOpenA(strAgent, INTERNET_OPEN_TYPE_PRECONFIG_WITH_NO_AUTOPROXY, NULL, NULL, 0);
else
  hOpen = InternetOpenA(strAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if(!hOpen)
{
  AfxMessageBox("Internet连接错误!");
  return -1;
}

DWORD dwSize;
CHAR szHead[] = "Accept: */*/r/n/r/n";
VOID* szTemp[16384];
HINTERNET hConnect;
CFile file;

if ( !(hConnect = InternetOpenUrlA ( hOpen, szUrl, szHead,
   lstrlenA (szHead), INTERNET_FLAG_DONT_CACHE | INTERNET_FLAG_PRAGMA_NOCACHE | INTERNET_FLAG_RELOAD, 0)))
{
    AfxMessageBox("不能打开该URL!");
    return -1;
}

if (file.Open(szFileName,CFile::modeWrite|CFile::modeCreate)==FALSE )
{
AfxMessageBox("不能打开本地的文件!");
return -1;
}

DWORD dwByteToRead = 0;
DWORD dwSizeOfRq = 4;
DWORD dwBytes = 0;

    if (!HttpQueryInfo(hConnect, HTTP_QUERY_CONTENT_LENGTH | HTTP_QUERY_FLAG_NUMBER,
                  (LPVOID)&dwByteToRead, &dwSizeOfRq, NULL))
{
  dwByteToRead = 0;
}

DWORD start;
DWORD end;
DWORD time;
CString tempstring;
time = 10;
start = timeGetTime();
do
{
  if (!InternetReadFile (hConnect, szTemp, 16384, &dwSize))
  {
   AfxMessageBox("读文件出错!");
   file.Close();
   return -1;
  }
  if (dwSize==0)
   break;
  else
   file.Write(szTemp,dwSize);
  dwBytes+=dwSize;
  if(dwByteToRead)
  {
   tempstring.Format("%d%%",(dwBytes*100)/dwByteToRead);
   SetDlgItemText(IDC_PERCENT_TEXT,tempstring);
  }
  FLOAT fSpeed = 0;
  fSpeed = (float)dwBytes;
  fSpeed /= ((float)time)/1000.0f;
  fSpeed /= 1024.0f;
  tempstring.Format("%dKB/s",fSpeed);
  SetDlgItemText(IDC_SPEED_TEXT,tempstring);
  end = timeGetTime();
  time = end - start;
  if(time == 0)
   time = 10;
}while (TRUE);

file.Close();
InternetCloseHandle(hOpen);

直接用socket完成HTTP下载

http://www.cnoffice.info/Program/VC/VCnet/Program_55135.html