rapidxml的常见读写操作

rapidxml官网地址：http://rapidxml.sourceforge.net/

rapidxml只包含4个hpp头文件，把这四个头文件放到项目中，即可使用rapidxml

#include <iostream>

#include <string>

#include <fstream>

#include "rapidxml.hpp"

#include "rapidxml_print.hpp"

static const int buf_len = ;

static char buf[buf_len] = {  };

void create(const char * file_name)

{

    rapidxml::xml_document<> doc;

    // 声明

    rapidxml::xml_node<>* declaration = doc.allocate_node(rapidxml::node_declaration);

    declaration->append_attribute(doc.allocate_attribute("version", "1.0"));

    declaration->append_attribute(doc.allocate_attribute("encoding", "utf-8"));

    doc.append_node(declaration);

    // 根节点

    rapidxml::xml_node<>* root = doc.allocate_node(rapidxml::node_element, "root");

    doc.append_node(root);

    // 注释节点1

    rapidxml::xml_node<>* comment1 = doc.allocate_node(rapidxml::node_comment, , "all students info");

    root->append_node(comment1);

    // 普通节点1

    rapidxml::xml_node<>* students = doc.allocate_node(rapidxml::node_element, "students");

    for (int i = ; i < ; ++i)

    {

        rapidxml::xml_node<>* one_student = doc.allocate_node(rapidxml::node_element, "student");

        sprintf(buf, "student_%02d", i);

        // doc.allocate_string 的作用是将源字符串深拷贝一份

        one_student->append_attribute(doc.allocate_attribute("name", doc.allocate_string(buf)));

        one_student->append_attribute(doc.allocate_attribute("score", doc.allocate_string(std::to_string( - i).c_str())));

        students->append_node(one_student);

    }

    root->append_node(students);

    // 注释节点2

    rapidxml::xml_node<>* comment2 = doc.allocate_node(rapidxml::node_comment, , "all books info");

    root->append_node(comment2);

    // 普通节点2

    rapidxml::xml_node<>* books = doc.allocate_node(rapidxml::node_element, "books");

    for (int i = ; i < ; ++i)

    {

        rapidxml::xml_node<>* one_book = doc.allocate_node(rapidxml::node_element, "book");

        sprintf(buf, "book_%02d", i);

        // doc.allocate_string 的作用是将源字符串深拷贝一份

        one_book->append_attribute(doc.allocate_attribute("name", doc.allocate_string(buf)));

        one_book->append_attribute(doc.allocate_attribute("price", doc.allocate_string(std::to_string( - i).c_str())));

        books->append_node(one_book);

    }

    root->append_node(books);

    std::ofstream outfile(file_name, std::ios::out);

    if (outfile)

    {

        char *end = rapidxml::print(buf, doc, );

        *end = ;

        outfile << buf;

        outfile.close();

    }

}

void parse(const char * file_name)

{

    std::ifstream infile(file_name, std::ios::in);

    if (!infile)

    {

        return;

    }

    infile.read(buf, buf_len);

    std::cout << buf << std::endl;

    rapidxml::xml_document<> doc;

    doc.parse<>(buf);

    // 取得根节点

    rapidxml::xml_node<> *root = doc.first_node("root");

    // 遍历students的子节点

    for (rapidxml::xml_node<> * node = root->first_node("students")->first_node(); node; node = node->next_sibling())

    {

        std::cout << node->first_attribute("name")->value() << ", "

                  << node->first_attribute("score")->value() << std::endl;

    }

    // 遍历books的子节点

    for (rapidxml::xml_node<> * node = root->first_node("books")->first_node(); node; node = node->next_sibling())

    {

        std::cout << node->first_attribute("name")->value() << ", "

                  << node->first_attribute("price")->value() << std::endl;

    }

}

int main()

{

    const char * file_name = "info.xml";

    create(file_name);

    parse(file_name);

    return ;

}

生成的示例文件：

<?xml version="1.0" encoding="utf-8"?>

<root>

    <!--all students info-->

    <students>

        <student name="student_00" score="100"/>

        <student name="student_01" score="99"/>

        <student name="student_02" score="98"/>

        <student name="student_03" score="97"/>

        <student name="student_04" score="96"/>

        <student name="student_05" score="95"/>

        <student name="student_06" score="94"/>

        <student name="student_07" score="93"/>

        <student name="student_08" score="92"/>

        <student name="student_09" score="91"/>

    </students>

    <!--all books info-->

    <books>

        <book name="book_00" price="50"/>

        <book name="book_01" price="49"/>

        <book name="book_02" price="48"/>

        <book name="book_03" price="47"/>

        <book name="book_04" price="46"/>

        <book name="book_05" price="45"/>

        <book name="book_06" price="44"/>

        <book name="book_07" price="43"/>

        <book name="book_08" price="42"/>

        <book name="book_09" price="41"/>

    </books>

</root>