c++ - 如何使用 pugixml 读取节点？

Question

我刚刚下载了 pugixml 库，我正在努力使其适应我的需要。它主要面向我未使用的 DOM 样式。我存储的数据如下所示:

<?xml version="1.0" encoding="UTF-8"?>
<profile>
    <points>
        <point>
            <index>0</index>
            <x>0</x>
            <y>50</y>
        </point>
        <point>
            <index>1</index>
            <x>2</x>
            <y>49.9583</y>
        </point>
        <point>
            <index>2</index>
            <x>12</x>
            <y>50.3083</y>
        </point>
     </points>
</profile>

Pugixml guide说:

It is common to store data as text contents of some node - i.e. This is a node. In this case, node does not have a value, but instead has a child of type node_pcdata with value "This is a node". pugixml provides child_value() and text() helper functions to parse such data.

但我在使用这些方法时遇到问题，我没有得到节点值。

#include "pugixml.hpp"

#include <string.h>
#include <iostream>

int main()
{
    pugi::xml_document doc;
    if (!doc.load_file("/home/lukasz/Programy/eclipse_linux_projects/xmlTest/Debug/pidtest.xml"))
        return -1;

    pugi::xml_node points = doc.child("profile").child("points");

    for (pugi::xml_node point = points.first_child(); point; point = points.next_sibling())
    {
        // ?
    }


    return 0;
}

如何读出for里面的index,x,y值？我愿意提供所有帮助。

Answer 1

有几种方法，在快速入门页面中有介绍:

• http://pugixml.org/docs/samples/traverse_iter.cpp
• http://pugixml.org/docs/samples/traverse_rangefor.cpp
• 有一个电力工作的树访客 http://pugixml.org/docs/samples/traverse_walker.cpp

我可以推荐 Xpath 吗？

#include <pugixml.hpp>
#include <iostream>

int main()
{
    pugi::xml_document doc;

    if (doc.load_file("input.txt")) {
        for (auto point : doc.select_nodes("//profile/points/point")) {
            point.node().print(std::cout, "", pugi::format_raw);
            std::cout << "\n";
        }
    }
}

打印

<point><index>0</index><x>0</x><y>50</y></point>
<point><index>1</index><x>2</x><y>49.9583</y></point>
<point><index>2</index><x>12</x><y>50.3083</y></point>