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