c++ json转xml

可以使用第三方库，比如RapidJSON。以下是一个示例：

#include "rapidjson/document.h"
#include "rapidjson/writer.h"
#include "rapidjson/stringbuffer.h"
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_print.hpp"
#include <iostream>
#include <fstream>

using namespace rapidjson;

int main() {
    // 读取JSON文件
    std::ifstream ifs("example.json");
    std::string content((std::istreambuf_iterator<char>(ifs)),
                        (std::istreambuf_iterator<char>()));

    // 解析JSON
    Document d;
    d.Parse(content.c_str());

    // 创建XML文档
    rapidxml::xml_document<> doc;

    // 创建根节点
    rapidxml::xml_node<> *root = doc.allocate_node(rapidxml::node_element, "root");
    doc.append_node(root);

    // 将JSON转换为XML
    for (Value::ConstMemberIterator itr = d.MemberBegin(); itr != d.MemberEnd(); ++itr) {
        rapidxml::xml_node<> *node = doc.allocate_node(rapidxml::node_element, itr->name.GetString());
        root->append_node(node);

        if (itr->value.IsObject()) {
            for (Value::ConstMemberIterator itr2 = itr->value.MemberBegin(); itr2 != itr->value.MemberEnd(); ++itr2) {
                rapidxml::xml_node<> *sub_node = doc.allocate_node(rapidxml::node_element, itr2->name.GetString());
                sub_node->value(doc.allocate_string(itr2->value.GetString()));
                node->append_node(sub_node);
            }
        } else if (itr->value.IsArray()) {
            for (Value::ConstValueIterator itr2 = itr->value.Begin(); itr2 != itr->value.End(); ++itr2) {
                rapidxml::xml_node<> *sub_node = doc.allocate_node(rapidxml::node_element, "item");
                sub_node->value(doc.allocate_string(itr2->GetString()));
                node->append_node(sub_node);
            }
        } else {
            node->value(doc.allocate_string(itr->value.GetString()));
        }
    }

    // 输出XML
    std::string result;
    rapidxml::print(std::back_inserter(result), doc, 0);
    std::cout << result << std::endl;

    return 0;
}

注意，代码中使用了RapidJSON和RapidXML两个库，需要先安装它们。