C++自己写的HTTP类

/**
 * 发起HTTP请求
 */
#define NORMAL_CONNECT        INTERNET_FLAG_KEEP_CONNECTION
#define SECURE_CONNECT        NORMAL_CONNECT | INTERNET_FLAG_SECURE
#define NORMAL_REQUEST        INTERNET_FLAG_RELOAD | INTERNET_FLAG_DONT_CACHE
#define SECURE_REQUEST        NORMAL_REQUEST | INTERNET_FLAG_SECURE | INTERNET_FLAG_IGNORE_CERT_CN_INVALID

int HttpCall(CString Url, int RequestType, CString SendPacket, CString* RecvPacket)
{
  if (Url.IsEmpty() || Url.GetLength()<=0) {
    return RET_PARAMS_ERROR;
  }
  CInternetSession session;
  CString strObject, strHost;
  DWORD dwServiceType;
  INTERNET_PORT nPort;
  if (AfxParseURL(Url, dwServiceType, strHost, strObject, nPort)==0) {
    return RET_URL_PARSE_ERROR;
  }
  try {
    CHttpConnection* pHttp = session.GetHttpConnection(strHost, 0, nPort, NULL, NULL);
    if (pHttp==NULL) {
      session.Close();
      return RET_HTTP_CONNECT_ERROR;
    }
    CHttpFile *pF = pHttp->OpenRequest(RequestType, strObject, NULL, 1, NULL, "HTTP/1.1", INTERNET_FLAG_NO_COOKIES|INTERNET_FLAG_DONT_CACHE);
    if (pF==NULL) {
      session.Close();
      delete pHttp;
      pHttp = NULL;
      return RET_HTTP_REQUEST_ERROR;
    }
    pF->AddRequestHeaders("Content-Type: application/x-www-form-urlencoded; charset=UTF-8");
    DWORD dwRet;
    CString strContentLength;
    int nContentLen = SendPacket.GetLength();
    strContentLength.Format("Content-Length: %d", nContentLen);
    pF->AddRequestHeaders(strContentLength);
    pF->SendRequest(NULL, 0, (LPVOID)(LPCTSTR)SendPacket, nContentLen);
    pF->QueryInfoStatusCode(dwRet);
    if (dwRet!=HTTP_STATUS_OK) {
      session.Close();
      delete pHttp;
      pHttp = NULL;
      return RET_HTTP_RESPONSE_ERROR;
    }
    CString strBuffer, strRead;
    while(pF->ReadString(strRead)) {
      strBuffer += "\r\n";
      strBuffer += strRead;
    }
    session.Close();
    pHttp->Close();
    delete pHttp;
    pF->Close();
    delete pF;
    strBuffer.TrimLeft("\r\n");
#ifdef _DEBUG
    // 写原始包文
#endif
    char* szGbkBuf = new char[strBuffer.GetLength()*1.5+1];
    if (szGbkBuf==NULL) {
      return RET_NOT_ENOUGH_MEMORY;
    }
    L_Utf8ToGbk((LPCTSTR)strBuffer, szGbkBuf, strBuffer.GetLength()*1.5);

    *RecvPacket = szGbkBuf;
    delete szGbkBuf;
    return 0;
  } catch(CInternetException *e) {
    if (e->m_dwError==ERROR_INTERNET_TIMEOUT) {
    }
  } catch(CException *e) {
    TCHAR szTextMsg[MAX_PATH+1];
    e->GetErrorMessage(szTextMsg, MAX_PATH);
    }
  return RET_FUNCTION_ERROR;
}