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 
#include <string>
#include 
#include "rapidxml.hpp"
#include "rapidxml_print.hpp"

static const int buf_len = 1024;
static char buf[buf_len] = { 0 };

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, 0, "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 = 0; i < 10; ++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(100 - 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, 0, "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 = 0; i < 10; ++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(50 - 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, 0);
        *end = 0;
        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<0>(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 0;
}

生成的示例文件：

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