使用JSON分析问题警告

我正在尝试从网站读取JSON数据。我在Windows 10上使用带有mingw编译器的Dev C++。这是我试图在静态项目中运行的教程中的JSON解析器：

#define CURL_STATICLIB
#include <cstdint>
#include <iostream>
#include <memory>
#include <string>
#include <sstream>
#include "curl.h"
#include "json.h"
namespace
{
std::size_t callback(
const char* in,
std::size_t size,
std::size_t num,
std::string* out)
{
const std::size_t totalBytes(size * num);
out->append(in, totalBytes);
return totalBytes;
}
}
int main()
{
const std::string url("http://date.jsontest.com/");
CURL* curl = curl_easy_init();
// Set remote URL.
curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
// Don't bother trying IPv6, which would increase DNS resolution time.
curl_easy_setopt(curl, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4);
// Don't wait forever, time out after 10 seconds.
curl_easy_setopt(curl, CURLOPT_TIMEOUT, 10);
// Follow HTTP redirects if necessary.
curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
// Response information.
int httpCode(0);
// std::unique_ptr<std::string> httpData(new std::string());
std::stringstream httpData;
// Hook up data handling function.
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, callback);
// Hook up data container (will be passed as the last parameter to the
// callback handling function).  Can be any pointer type, since it will
// internally be passed as a void pointer.
curl_easy_setopt(curl, CURLOPT_WRITEDATA, &httpData);
// Run our HTTP GET command, capture the HTTP response code, and clean up.
curl_easy_perform(curl);
curl_easy_getinfo(curl, CURLINFO_RESPONSE_CODE, &httpCode);
curl_easy_cleanup(curl);
if (httpCode == 200)
{
std::cout << "nGot successful response from " << url << std::endl;
// Response looks good - done using Curl now.  Try to parse the results
// and print them out.
Json::Value jsonData;
Json::CharReaderBuilder jsonReader;
std::string errs;
if (Json::parseFromStream(jsonReader, httpData, &jsonData, &errs))
// jsonReader.parse(httpData, jsonData))
{
std::cout << "Successfully parsed JSON data" << std::endl;
std::cout << "nJSON data received:" << std::endl;
std::cout << jsonData.toStyledString() << std::endl;
const std::string dateString(jsonData["date"].asString());
const std::size_t unixTimeMs(
jsonData["milliseconds_since_epoch"].asUInt64());
const std::string timeString(jsonData["time"].asString());
std::cout << "Natively parsed:" << std::endl;
std::cout << "tDate string: " << dateString << std::endl;
std::cout << "tUnix timeMs: " << unixTimeMs << std::endl;
std::cout << "tTime string: " << timeString << std::endl;
std::cout << std::endl;
}
else
{
std::cout << "Could not parse HTTP data as JSON" << std::endl;
std::cout << "HTTP data was:n" << httpData.str() << std::endl;
return 1;
}
}
else
{
std::cout << "Couldn't GET from " << url << " - exiting" << std::endl;
return 1;
}
return 0;
}

这就是我一直遇到的错误：

[警告]不赞成使用"Reader"(声明于C：/Users/me/Downloads/jsoncp-master/jsoncpp-master/include/json/rereader.h:35)：|请改用CharReader和CharReaderBuilder[-W不赞成声明]

我认为语法较旧，因此我将对象的术语替换为推荐的术语。现在我得到这个错误：这是我更正的区块：

Json::Value jsonData;
Json::CharReaderBuilder CharReader;
if (CharReader.parse(*httpData, jsonData))

这就是新的错误：

错误："class Json:：CharReaderBuilder"没有名为"parse"的成员if(CharReader.parse(*httpData，jsonData))

以上代码更正了此问题。特定问题已得到纠正。但是，由于库问题，这是我在编译时的新错误。

g++.exe main.o -o CurlProject1.exe -L"C:/Program Files (x86)/Dev-Cpp/MinGW64/lib" -L"C:/Program Files (x86)/Dev-Cpp/MinGW64/x86_64-w64-mingw32/lib" -L"C:/Users/me/Downloads/curl-7.56.1-win64-mingw/lib" -static-libgcc -L"C:/Users/me/Downloads/curl-7.56.1-win64-mingw/lib" ../../Downloads/curl-7.56.1-win64-mingw/lib/libcurl.a ../../Downloads/curl-7.56.1-win64-mingw/lib/libcurl.dll.a
main.o:main.cpp:(.text+0x207): undefined reference to `Json::Value::Value(Json::ValueType)'
main.o:main.cpp:(.text+0x213): undefined reference to `Json::CharReaderBuilder::CharReaderBuilder()'
main.o:main.cpp:(.text+0x242): undefined reference to `Json::parseFromStream(Json::CharReader::Factory const&, std::istream&, Json::Value*, std::string*)'
main.o:main.cpp:(.text+0x2a1): undefined reference to `Json::Value::toStyledString() const'
main.o:main.cpp:(.text+0x2e8): undefined reference to `Json::Value::operator[](char const*)'