RapidXml 读取文件并遍历节点的所有属性

RapidXml 试图成为最快的 XML DOM 解析工具包，同时保证解析结果的可用性、可移植性以及与 W3C 标准的兼容性。RapidXml 使用 C++ 编写，因此在操作同一数据时，其解析速度接近于 strlen() 函数。

整个解析工具包包含在一个头文件中，所以使用时不用编译也不用连接。要想使用 RapidXml 只要包含 rapidxml.hpp 即可，当然如果要用附加功能（如打印函数），你可以包含 rapidxml_print.hpp 文件。

RapidXml 为采用C++语言操作XML提供了机遇，同时结合XMPP协议也开启了诸如Wt、CxServer等基于C++的网络应用在即时通讯领域的更宽广的发展空间。

rapidxml 下载地址：https://sourceforge.net/projects/rapidxml/

测试示例：

读取xml文件，并遍历所有节点的所有属性。xml的文件内容如下：

<?xml version="1.0" encoding="UTF-8"?><EllipsoidParams>  <Datum Name="BeiJing54" SemiMajorAxis="6378245.0" Flattening="298.3"/>  <Datum Name="XiAn80" SemiMajorAxis="6378140.0" Flattening="298.257"/>  <Datum Name="CGCS2000" SemiMajorAxis="6378137.0" Flattening="298.257222101"/>  <Datum Name="WGS-84" SemiMajorAxis="6378137.0" Flattening="298.257223563"/>  <Datum Name="WGS-72" SemiMajorAxis="6378135.0" Flattening="298.26"/>  <Datum Name="WGS-66" SemiMajorAxis="6378145.0" Flattening="298.25"/>  <Datum Name="WGS-60" SemiMajorAxis="6378165.0" Flattening="298.3"/>  <Datum Name="Krassovsky" SemiMajorAxis="6378245.0" Flattening="298.3"/>  <Datum Name="International" SemiMajorAxis="6378388.0" Flattening="297.0"/>  <Datum Name="MERIT-83" SemiMajorAxis="6378137.0" Flattening="298.257"/>  <Datum Name="SGS85" SemiMajorAxis="6378136.0" Flattening="298.257"/>  <Datum Name="GRS80" SemiMajorAxis="6378137.0" Flattening="298.257222101"/>  <Datum Name="GRS75" SemiMajorAxis="6378140.0" Flattening="298.257"/>  <Datum Name="Airy 1830" SemiMajorAxis="6377563.396" Flattening="299.3249753150"/>  <Datum Name="Modified Airy" SemiMajorAxis="6377340.189" Flattening="299.32493736548"/>  <Datum Name="Aust_SA" SemiMajorAxis="6378160.0" Flattening="298.25"/>  <Datum Name="Bessel 1841" SemiMajorAxis="6377397.155" Flattening="299.15281285"/>  <Datum Name="Clarke 1880" SemiMajorAxis="6378249.145" Flattening="293.4663"/>  <Datum Name="Clarke 1866" SemiMajorAxis="6378206.4" Flattening="294.9786982139"/>  <Datum Name="GRS67" SemiMajorAxis="6378160.0" Flattening="298.247167427"/>  <Datum Name="APL4.9" SemiMajorAxis="6378137.0" Flattening="298.25"/>  <Datum Name="Andrae" SemiMajorAxis="6377104.43" Flattening="300.0"/>  <Datum Name="Bessel_nam" SemiMajorAxis="6377483.865" Flattening="299.1528128"/>  <Datum Name="CPM" SemiMajorAxis="6375738.7" Flattening="334.29"/>  <Datum Name="Delamber" SemiMajorAxis="6376428.0" Flattening="311.5"/>  <Datum Name="Engelis" SemiMajorAxis="6378136.05" Flattening="298.2566"/>  <Datum Name="Everest30" SemiMajorAxis="6377276.345" Flattening="300.8017"/>  <Datum Name="Everest48" SemiMajorAxis="6377304.063" Flattening="300.8017"/>  <Datum Name="Everest56" SemiMajorAxis="6377301.243" Flattening="300.8017"/>  <Datum Name="Everest69" SemiMajorAxis="6377295.664" Flattening="300.8017"/>  <Datum Name="EverestSS" SemiMajorAxis="6377298.556" Flattening="300.8017"/>  <Datum Name="Fischer60" SemiMajorAxis="6378166.0" Flattening="298.3"/>  <Datum Name="Fischer60m" SemiMajorAxis="6378155.0" Flattening="298.3"/>  <Datum Name="Fischer68" SemiMajorAxis="6378150.0" Flattening="298.3"/>  <Datum Name="Helmert" SemiMajorAxis="6378200.0" Flattening="298.3"/>  <Datum Name="Hough" SemiMajorAxis="6378270.0" Flattening="297.0"/>  <Datum Name="IAU76" SemiMajorAxis="6378140.0" Flattening="298.257"/>  <Datum Name="Kaula" SemiMajorAxis="6378163.0" Flattening="298.24"/>  <Datum Name="Lerch" SemiMajorAxis="6378139.0" Flattening="298.257"/>  <Datum Name="Maupertius" SemiMajorAxis="6397300.0" Flattening="191.0"/>  <Datum Name="New_intl" SemiMajorAxis="6378157.5" Flattening="298.24961539"/>  <Datum Name="NWL9D" SemiMajorAxis="6378145.0" Flattening="298.25"/>  <Datum Name="Plessis" SemiMajorAxis="6376523.0" Flattening="0.0"/>  <Datum Name="Southeast_asia" SemiMajorAxis="6378155.0" Flattening="298.3000002409"/>  <Datum Name="Sphere" SemiMajorAxis="6370997.0" Flattening="298.257"/>  <Datum Name="Walbeck" SemiMajorAxis="6376896.0" Flattening="302.7800001817"/></EllipsoidParams>

测试程序代码：

#include <tchar.h>#include <string>#include <iostream>#include "rapidxml/rapidxml.hpp"#include "rapidxml/rapidxml_utils.hpp"//rapidxml::file#include "rapidxml/rapidxml_print.hpp"//rapidxml::printusing namespace rapidxml;std::string ReadFile(const char* fileName){std::string strBuffer;FILE *fp = fopen(fileName, "rb");if(NULL == fp){return "";}char buf[1024];while(true){const size_t byteRead = fread(buf, 1, sizeof(buf), fp);if(0 == byteRead){break;}strBuffer.insert(strBuffer.end(), buf, buf+byteRead);}fclose(fp);return strBuffer;}//int ReadFileAndTraversal(){//读取文件内容std::string szFileBuf = ReadFile("./Ellipsoid.xml");//使用rapidxml::file读取文件更方便rapidxml::file<> fdoc("Ellipsoid.xml");//打印读取的内容std::cout << fdoc.data() << std::endl;rapidxml::xml_document<> doc;doc.parse<0>(fdoc.data());//doc.parse<0>(szFileBuf.c_str());//打印整个XML内容std::cout << doc.name() << std::endl;//在XML文档中寻找第一个节点const rapidxml::xml_node<> *ellipsoid = doc.first_node("EllipsoidParams");if(NULL == ellipsoid){return -1;}//遍历所有椭球信息for(rapidxml::xml_node<> *datum = ellipsoid->first_node("Datum");NULL != datum;datum = datum->next_sibling()){//遍历单个椭球的所有属性std::string szTmp("");for(rapidxml::xml_attribute<char> * attr = datum->first_attribute("Name");attr != NULL;attr = attr->next_attribute()){szTmp.append(attr->name());//name() value()返回的字符串不会去掉首尾的空白字符szTmp.append(": ");szTmp.append(attr->value());szTmp.append(", ");}std::cout << szTmp.c_str() << std::endl;}return 0;}//int _tmain(int argc, _TCHAR* argv[]){//读取文件并打印整个文件ReadFileAndTraversal();system("pause");return 0;}