问如何使用C++中的wininet从web上获取json的数据？

EN

string GetLocation() {
    DWORD size = 0;
    DWORD wrt;
    LPCWSTR down = L"Downloader";
    string msg = "";

    /*wstring ipConvert(ipAdr().begin(), ipAdr().end());
    LPCWSTR ip = ipConvert.c_str();*/

    string url = "http://ip-api.com/json/168.197.155.244";
    wstring urlConvert(url.begin(), url.end());
    LPCWSTR urlFinal = L"http://ip-api.com/json/168.197.155.244";
    LPCWSTR headers = L"Content-Type: application/json\r\n";


    HINTERNET open = InternetOpen(down, INTERNET_OPEN_TYPE_DIRECT, NULL, NULL, 0);
    HINTERNET connect = InternetConnect(open, urlFinal, NULL, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
    HINTERNET request = HttpOpenRequest(connect, NULL, urlFinal, NULL, NULL, 0, 0, 0);
    HttpAddRequestHeaders(request, headers, -1, HTTP_ADDREQ_FLAG_ADD);

    HttpSendRequest(request, NULL, 0, NULL, 0);
    InternetQueryDataAvailable(request, &size, 0, 0);
    char* buff = new char[size + 1];
    memset(buff, 0, size + 1);

    InternetReadFile(request, buff, size, &wrt);
    msg += buff;

    InternetCloseHandle(open);
    InternetCloseHandle(connect);
    InternetCloseHandle(request);

    return msg;
}