使用tinyxml创建及解析XML文件

迷南。 2022-06-06 01:06 292阅读 0赞

# 创建并读取如下xml文件： #

<?xml version="1.0" encoding="utf-8" ?>
    <Students>
      <Student id = "1">
        <Name>MaZhe</Name>
        <Age>18</Age>
      </Student>
      <Student id = "2">
        <Name>MaZhe</Name>
        <Age>18</Age>
      </Student>
      <Student id = "3">
        <Name>MaZhe</Name>
        <Age>18</Age>
      </Student>
    </Students>

# 代码实现： #

#include <iostream>
    #include <string>
    #include <vector>
    #include <list>
    #include <cassert>
    
    #include "tinyxml.h"
    
    using namespace std;
    
    static const char* kFileName = "students.xml";
    
    // 链接问题：另外从error LNK2001: 无法解析的外部符号 "private: static struct TiXmlString::Rep TiXmlString::nullrep_" 
    // (?nullrep_@TiXmlString@@0URep@1@A)，这个错误出现的原因是因为你使用的是非stl版本的string类型。
    // 如果你没有在工程中定义TIXML_USE_STL，那么你一定要加载tinystr.cpp；否则你可以不用添加tinystr.cpp到工程中。
    
    struct Student {
      int id;
      std::string name;
      int age;
    
      Student(int id_, const std::string& name_, int age_)
          : id(id_)
          , name(name_)
          , age(age_) {
      }
    
      void Print() const {
        std::cout << "Id: " << id << ", Name: " << name << ", Age: " << age << std::endl;
      }
    };
    
    static void WriteData() {
      // Prepare data.
      std::list<Student> students;
      students.push_back(Student(1, "MaZhe", 18));
      students.push_back(Student(2, "Miki", 19));
      students.push_back(Student(3, "Maki", 20));
    
      // Serialization.
      TiXmlDocument xdoc;
    
      TiXmlDeclaration* xdec = new TiXmlDeclaration("1.0", "utf-8", "yes");
      xdoc.LinkEndChild(xdec);
    
      TiXmlComment* xcomment = new TiXmlComment("This is students info in a class!");
      xdoc.LinkEndChild(xcomment);
    
      TiXmlElement* xstudents = new TiXmlElement("Students");
      for (const Student& student : students) {
        TiXmlElement* xstudent = new TiXmlElement("Student");
        xstudent->SetAttribute("id", student.id);
    
        TiXmlElement* xname = new TiXmlElement("Name");
        TiXmlText* xname_text = new TiXmlText(student.name.c_str());
        xname->LinkEndChild(xname_text);
        xstudent->LinkEndChild(xname);
    
        TiXmlElement* xage = new TiXmlElement("Age");
        char age[32] = { 0 };
        sprintf(age, "%d", student.age);
        TiXmlText* xage_text = new TiXmlText(age);
        xage->LinkEndChild(xage_text);
        xstudent->LinkEndChild(xage);
    
        xstudents->LinkEndChild(xstudent);
      }
    
      xdoc.LinkEndChild(xstudents);
    
      TiXmlPrinter printer;
      xdoc.Accept(&printer);
    
      std::cout << printer.CStr() << std::endl;
    
      xdoc.SaveFile(kFileName);
    }
    
    static std::string GetElementText(TiXmlElement* element) {
      if (element == NULL) {
        return "";
      }
    
      const char* value = element->GetText();
      if (value == NULL) {
        return "";
      }
    
      return value;
    }
    
    static int GetElementIntValue(TiXmlElement* element) {
      std::string value_str = GetElementText(element);
      if (value_str.empty()) {
        return 0;
      }
    
      return atoi(value_str.c_str());
    }
    
    static void ReadData() {
      std::list<Student> students;
    
      TiXmlDocument xdoc;
      if (!xdoc.LoadFile(kFileName)) {
        return;
      }
    
      TiXmlElement* xstudents = xdoc.RootElement();
      if (xstudents == NULL) {
        return;
      }
    
      TiXmlElement* xstudent = xstudents->FirstChildElement();
      while (xstudent != NULL) {
        int id = 0;
        xstudent->QueryIntAttribute("id", &id);
    
        TiXmlElement* xname = xstudent->FirstChildElement("Name");
        std::string name = GetElementText(xname);
    
        TiXmlElement* xage = xstudent->FirstChildElement("Age");
        int age = GetElementIntValue(xage);
    
        students.push_back(Student(id, name, age));
    
        xstudent = xstudent->NextSiblingElement();
      }
    
      for (const Student& student : students) {
        student.Print();
      }
    }
    
    int main() {
      WriteData();
      ReadData();
    
      return 0;
    }