c++ - 从 url 读取 xml 行

Question

我想从互联网 url(将输入 url)读取 xml 行并将日期值(dd、mm、yyyy)提取为字符串或 int。我怎样才能使用 visual c++,mfc 高效地做到这一点？

网页上可用的行如下所示。

谢谢。

<location>
<latitude>0</latitude>
<longitude>0</longitude>
</location>
<offset>0</offset>
<suffix>Z</suffix>
<localtime>11 Nov 2013 15:23:58</localtime>
<isotime>2013-11-11 15:23:58 +0000</isotime>
<utctime>2013-11-11 15:23:58</utctime>
<dst>False</dst>

Answer 1

感谢大家的所有评论。我搜索并使用了 cURL 库来解决我的问题。可能是一些示例的最简单方法。也感谢之前的主题，它帮助了很多:How do I download xml from the internet in C++

  size_t AppendDataToStringCurlCallback(void *ptr, size_t size, size_t nmemb, void        *vstring)
 {
std::string * pstring = (std::string*)vstring;
pstring->append((char*)ptr, size * nmemb);
return size * nmemb;
 }

 std::string DownloadUrlAsString(const std::string & url)
 {
std::string body;

CURL *curl_handle;
curl_global_init(CURL_GLOBAL_ALL);
curl_handle = curl_easy_init();
curl_easy_setopt(curl_handle, CURLOPT_URL, url.c_str());
curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, AppendDataToStringCurlCallback);
curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, &body);
curl_easy_perform(curl_handle); 
curl_easy_cleanup(curl_handle);

return body;
 }

 int main(void)
  {
CURL *curl;
CURLcode res;
std::string data_to_read;

curl = curl_easy_init();
if(curl) {
    //curl_easy_setopt(curl, CURLOPT_URL, "www.earthtools.org/timezone/0/0");

    data_to_read=DownloadUrlAsString("www.earthtools.org/timezone/0/0");
    res = curl_easy_perform(curl);

    // always cleanup 
    curl_easy_cleanup(curl);
}

std::string str=data_to_read;
std::string str2 ("<utctime>");


std::size_t found = str.find(str2);
if (found!=std::string::npos)
std::cout << "first data found at: " << found << '\n';
//data_to_read[found+9]


char year[4];//="yyyy";
char month[2];//="mm";
char day[2];//="dd";

int delta=0;
int start=found+9;
for (int k=start; k<start+10;k++)
{
    if(k<start+4){
        year[delta]= data_to_read[k];
        delta++;
    }
    else if (k==start+4)
        delta=0;
    else if ((k>=start+5) && (k<=start+6))
    {
        month[delta]=data_to_read[k];
        delta++;
    }
    else if (k==start+7)
        delta=0;
    else if ((k>=start+8) && (k<=start+9))
    {
        day[delta]=data_to_read[k];
        delta++;
    }


}


int year_m=atoi(year);
int month_m=atoi(month);
int day_m=atoi(day);