C++ 使用HttpRequest获取网页及UTF8转GB码

#include <iostream>
#include <windows.h>
#include <wininet.h>
using namespace std;
string HttpRequest(string strUrl, string strMethod="GET", string strPostData="", int nPostDataLen=0, short sPort=80)
{
  int pos;
  BOOL bRet;
  char *lpHostName, *lpUrl, *lpMethod, *lpPostData;
  string tmpUrl, strResponse = "";
  while ((pos = strUrl.find(" ")) != strUrl.npos) strUrl.erase(pos, 1); //删除网址中的空格 
  if (strUrl.substr(0,7) == "http://") strUrl=strUrl.substr(7, strUrl.size()-1); //删除网址中的协议名 
  if (strUrl.substr(0,8) == "https://") strUrl=strUrl.substr(8, strUrl.size()-1);
  if (strUrl.empty()) return strResponse;
  if ((pos=strUrl.find("/")) != strUrl.npos){
    tmpUrl = strUrl.substr(pos+1, strUrl.size()-1);
    strUrl = strUrl.substr(0, pos);
  } else tmpUrl = "/";
  lpUrl = (char*)tmpUrl.data();
  lpMethod = (char*)strMethod.data();
  lpHostName = (char*)strUrl.data();
  lpPostData = (char*)strPostData.data();
  HINTERNET hInternet, hConnect, hRequest;
  hInternet = hConnect = hRequest = NULL;
  hInternet = (HINSTANCE)InternetOpen("User-Agent", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
  if (!hInternet) return strResponse;
  hConnect = (HINSTANCE)InternetConnect(hInternet, lpHostName, sPort, NULL, "HTTP/1.1", INTERNET_SERVICE_HTTP, 0, 0);
  if (!hConnect){
    if (hInternet) InternetCloseHandle(hInternet);
    return strResponse;
  }
  hRequest = (HINSTANCE)HttpOpenRequest(hConnect, lpMethod, lpUrl, "HTTP/1.1", NULL, NULL, INTERNET_FLAG_RELOAD, 0);
  if (!hRequest){
    if (hInternet) InternetCloseHandle(hInternet);
    if (hConnect) InternetCloseHandle(hConnect);
    return strResponse;
  }
  bRet = HttpSendRequest(hRequest, NULL, 0, lpPostData, nPostDataLen);
  while (true){
    char cReadBuffer[4096];
    unsigned long lNumberOfBytesRead;
    bRet = InternetReadFile(hRequest, cReadBuffer, sizeof(cReadBuffer)-1, &lNumberOfBytesRead);
    if (!bRet || !lNumberOfBytesRead) break;
    cReadBuffer[lNumberOfBytesRead] = 0;
    strResponse = strResponse + cReadBuffer;
  }
  if (hRequest) InternetCloseHandle(hRequest);
  if (hConnect) InternetCloseHandle(hConnect);
  if (hInternet) InternetCloseHandle(hInternet);
  return strResponse;
}
string UTF8toGB(string s)
{
  WCHAR *strSrc;
  LPSTR szRes;
  char *str = (char*)s.data();
  int i = MultiByteToWideChar(CP_UTF8, 0, str, -1, NULL, 0);
  strSrc = new WCHAR[i+1];
  MultiByteToWideChar(CP_UTF8, 0, str, -1, strSrc, i);
  i = WideCharToMultiByte(CP_ACP, 0, strSrc, -1, NULL, 0, NULL, NULL);
  szRes = new CHAR[i+1];
  WideCharToMultiByte(CP_ACP, 0, strSrc, -1, szRes, i, NULL, NULL);
  s = szRes;
  delete[]strSrc;
  delete[]szRes;
  return s;
}
int main(void)
{
  string utf = "<meta charset=\"utf-8\">";
  string url = "https://blog.csdn.net/boysoft2002/article/details/113839813";
    string Html = HttpRequest(url);
  if (Html.find(utf)!=Html.npos)
    cout << UTF8toGB(Html);
  else
    cout << Html;
    return 0;
}