libcurl使用

static build need define macro CURL_STATICLIB in use project

libcurl.lib ws2_32.lib winmm.lib wldap32.lib

struct MemoryStruct {
	char *memory;
	size_t size;
};

static size_t WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
{
	size_t realsize = size * nmemb;
	struct MemoryStruct *mem = (struct MemoryStruct *)userp;

	mem->memory = (char*)realloc(mem->memory, mem->size + realsize + 1);
	if(mem->memory == NULL) {
		/* out of memory! */ 
		OutputDebugString(_T("yGPC:not enough memory (realloc returned NULL)\n"));
		return 0;
	}

	memcpy(&(mem->memory[mem->size]), contents, realsize);
	mem->size += realsize;
	mem->memory[mem->size] = 0;

	return realsize;
}

/**
HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Fri, 30 Sep 2016 07:34:51 GMT

{"head":{"errorCode":"000000","errorMsg":"success"},"body":{"commands":null}

 */
int CMainDlg::httpPost(const std::string & strUrl, const std::string & strPostField, std::string & strRet)
{

	std::wstring str = _T("yGPC: CMainDlg::httpPost strUrl:");
	str += m_ut.s2w(strUrl) + _T(" postField: ");
	str += m_ut.s2w(strPostField);
	m_ut.strRemoveByParam(str, _T("\r\n"));
	OutputDebugString(str.c_str());

	CURL *curl; 
	CURLcode res; 
	struct curl_slist *http_header = NULL; 
	struct MemoryStruct chunk;
	chunk.memory = (char*)malloc(1);  /* will be grown as needed by realloc above */ 
	chunk.size = 0;    /* no data at this point */ 

	curl_global_init(CURL_GLOBAL_ALL);
	curl = curl_easy_init(); 
	if (!curl) 
	{ 
		OutputDebugString(_T("yGPC:curl init failed\n"));
		return -1; 
	} 

std::string  strUrlEncode = boost::locale::conv::to_utf<char>(strUrl,"GBK");
	curl_easy_setopt(curl,CURLOPT_URL,strUrlEncode.c_str()); //url地址
	curl_easy_setopt(curl,CURLOPT_POSTFIELDS,strPostField.c_str()); //post参数
	curl_easy_setopt(curl,CURLOPT_WRITEFUNCTION,WriteMemoryCallback); //对返回的数据进行操作的函数地址
	curl_easy_setopt(curl,CURLOPT_WRITEDATA,(void *)&chunk); //这是write_data的第四个参数值
	curl_easy_setopt(curl,CURLOPT_POST,1); //设置问非表示本次操作为post 
	curl_easy_setopt(curl,CURLOPT_VERBOSE,1); //打印调试信息
//	curl_easy_setopt(curl,CURLOPT_HEADER,1); //将响应头信息和相应体一起传给write_data 
	curl_easy_setopt(curl,CURLOPT_FOLLOWLOCATION,1); //设置为非,响应头信息location 
	curl_easy_setopt(curl,CURLOPT_COOKIEFILE,"/curlposttest.cookie"); 
	curl_easy_setopt(curl,CURLOPT_TIMEOUT,10); 


	res = curl_easy_perform(curl); 

	if (res != CURLE_OK) 
	{ 
		switch(res) 
		{ 
		case CURLE_UNSUPPORTED_PROTOCOL: 
			OutputDebugString(_T("yGPC:CURLE_UNSUPPORTED_PROTOCOL\n"));
			break;
		case CURLE_COULDNT_CONNECT: 
			OutputDebugString(_T("yGPC:CURLE_COULDNT_CONNECT\n"));
			break;
		case CURLE_HTTP_RETURNED_ERROR: 
			OutputDebugString(_T("yGPC:CURLE_HTTP_RETURNED_ERROR\n"));
			break;
		case CURLE_READ_ERROR: 
			OutputDebugString(_T("yGPC:CURLE_READ_ERROR\n"));
			break;
		default: 
			{
				std::string str = ("yGPC:");
				str += ("return code:");
				str += m_ut.w2s(m_ut.number2str(res,_T("%x")));
				OutputDebugString(_T("yGPC:CURLE_READ_ERROR\n"));
			}
			break;
		} 
		return -1; 
	} else
	{
		strRet = chunk.memory;
	}
	curl_easy_cleanup(curl); 
	free(chunk.memory);
	/* we're done with libcurl, so clean it up */ 
	curl_global_cleanup();

	return 0;

}

jo["signature"] = genSignature(strTimestamp,strRandom).c_str();
		jo["timestamp"] = strTimestamp.c_str();
		jo["requestTime"] = strTimestamp.c_str();
		jo["nonce"] = strRandom.c_str();
		jsonRoot["head"] = jo;

		std::string param = "msg=";
		param += jsonRoot.toStyledString();
		std::string  strUrlEncode = boost::locale::conv::to_utf<char>(param,"GBK");
		std::string strRet;
		pwnd->httpPost(url,strUrlEncode,strRet);