libcurl第三課 HTTP獲取天氣信息

場景說明
?????? 從 t.weather.sojson.com網(wǎng)頁中獲取天氣信息。如果不使用libcurl庫，需要實現(xiàn)Transfer-Encoding: chunked分塊接收和Content-Encoding: gzip解壓，現(xiàn)在提供libcurl實現(xiàn)代碼

代碼
size_t WriteResponseBody(void *ptr, size_t size, size_t nmemb, void *userData)
{
?std::string* pStrBuffer = (std::string*)userData;
?size_t nLen = size * nmemb;
?pStrBuffer->append((char*)ptr, nLen);
?return nLen;
}
int GetWeatherUsingCurl(const std::string &strUrl, std::string& strResponseData)
{
?CURL *pCurlHandle = curl_easy_init();
?curl_easy_setopt(pCurlHandle, CURLOPT_CUSTOMREQUEST, "GET");
?curl_easy_setopt(pCurlHandle, CURLOPT_URL, strUrl.c_str());
?curl_easy_setopt(pCurlHandle, CURLOPT_WRITEFUNCTION, WriteResponseBody);//設(shè)置回調(diào)函數(shù)
?//curl_easy_setopt(pCurlHandle, CURLOPT_HEADER, 1);//保存HTTP頭部信息到strResponseData
?curl_easy_setopt(pCurlHandle, CURLOPT_WRITEDATA, &strResponseData);//設(shè)置回調(diào)函數(shù)的參數(shù),獲取反饋信息
?curl_easy_setopt(pCurlHandle, CURLOPT_TIMEOUT, 15);//接收數(shù)據(jù)時超時設(shè)置，如果10秒內(nèi)數(shù)據(jù)未接收完，直接退出
?curl_easy_setopt(pCurlHandle, CURLOPT_MAXREDIRS, 1);//查找次數(shù)，防止查找太深
?curl_easy_setopt(pCurlHandle, CURLOPT_CONNECTTIMEOUT, 5);//連接超時，這個數(shù)值如果設(shè)置太短可能導(dǎo)致數(shù)據(jù)請求不到就斷開了
?CURLcode nRet = curl_easy_perform(pCurlHandle);
?curl_easy_cleanup(pCurlHandle);
?return nRet;
}

調(diào)用例子
?std::string strResponseData;
?GetWeatherUsingCurl("t.weather.sojson.com/api/weather/city/101200101", strResponseData);