boostproperty_ptree库解析XML文件

看到boost里面有个property_ptree库不错，于是到网上下载了一个xml文件测试了一下，还真的比较好用，觉得比tinyXML库还好用，使用方法比较简单。

该库还可以解析ini, info, json文件，但我没试过。

xml文件大小为223kb，解析完如果不在命名窗口进行输出用了7s左右。

获得元素值使用ptree类的成员模板函数get,在模板参数中说明数据类型，在参数列表中填写路径，路径的表示也很简况，之间用点号分隔。

获得元素属性只需要在路径中的属性名称前面加上标记就可以了，还有获得注释等。

对于有多个子元素的元素结点，我们可以使用getChild()来获得它的子结点，然后就可以像使用STL中的迭代器一样对子元素进行遍历操作。

注意get和getChild的路径参数，多调试一下也是极好的。

具体用法可以参照下面的代码:

注意在使用get方法时最好给出第二个参数用作默认值，这样如果没有找到该属性，函数会返回该默认值，否则，程序会崩溃，最好对getChild

方法进行异常的捕获，以提高程序的鲁棒性。

文件结构复杂度适中：

解析代码如下:

#include 
#include 
#include 
#include 
#include 
#include 
#include 

#include "boost/timer.hpp"
#include "boost/property_tree/ptree.hpp"
#include "boost/property_tree/xml_parser.hpp"
#include "boost/property_tree/exceptions.hpp"

using namespace std;

struct _head
{
	wstring revMajor;
	wstring revMinor;
	wstring name;
	wstring version;
	wstring date;
	wstring north;
	wstring south;
	wstring east;
	wstring west;
	wstring maxRoad;
	wstring maxJunc;
	wstring maxPrg;
};

struct _predecessor
{
	wstring elementType;
	wstring elementId;
	wstring contactPoint;
};

struct _link
{
	_predecessor predecessor;
	_predecessor successor;
};

struct _geometry
{
	wstring s;
	wstring x;
	wstring y;
	wstring hdg;
	wstring length;
};

typedef vector<_geometry> planView_vec;

struct _elevationProfile
{
	wstring s;
	wstring a;
	wstring b;
	wstring c;
	wstring d;
};

struct _superelevation
{
	wstring s;
	wstring a;
	wstring b;
	wstring c;
	wstring d;
};

typedef vector<_superelevation> lateralProfile_vec;

struct _road
{
	wstring name;
	wstring length;
	wstring id;
	wstring junction;
	_link	link;
	planView_vec planeView;
	_elevationProfile elevationProfile;
	lateralProfile_vec lateralProfile;
	//... more
	//lanes
	//objects
	//signals
};

typedef vector<_road> road_vec;

struct _junction
{
	wstring name;
	wstring id;
	//... more
	//connection
	//
};

typedef vector<_junction> junction_vec;

struct _OpenDriveXML
{
	_head head;
	road_vec road_vc;
	junction_vec junction_vc;
};

//////////////////////////////////////////////////////////////////////////
int main()
{
	typedef boost::property_tree::basic_ptree::value_type _value_type;
	typedef boost::property_tree::basic_ptree				_self_type;
	boost::property_tree::wptree pt;
	_OpenDriveXML OD_xml;

	boost::timer tm;

	boost::property_tree::xml_parser::read_xml("E:\\vs2013 programs\\ACM_NYOJ_Solution\\Win32\\Debug\\Bin\\sample1.xml", pt);
	//par_xml.head.date = 
	wstring par = pt.data();
	wstring itr = pt.get(_T("OpenDRIVE.header..revMajor"));
	//boost::property_tree::ptree planeview_tr = pt.get_child(_T("OpenDRIVE.road.planView"));
	_self_type odChild = pt.get_child(_T("OpenDRIVE"));

	for (auto itr = odChild.begin(); itr != odChild.end(); ++itr)
	{
		if (itr->first == _T("header"))
		{
			OD_xml.head.revMajor = itr->second.get(_T(".revMajor"));
			OD_xml.head.revMinor = itr->second.get(_T(".revMinor"));
			OD_xml.head.name = itr->second.get(_T(".name"));
			OD_xml.head.version = itr->second.get(_T(".version"));
			OD_xml.head.date = itr->second.get(_T(".date"));
			OD_xml.head.north = itr->second.get(_T(".north"));
			OD_xml.head.south = itr->second.get(_T(".south"));
			OD_xml.head.east = itr->second.get(_T(".east"));
			OD_xml.head.west = itr->second.get(_T(".west"));
			OD_xml.head.maxRoad = itr->second.get(_T(".maxRoad"));
			OD_xml.head.maxJunc = itr->second.get(_T(".maxJunc"));
			OD_xml.head.maxPrg = itr->second.get(_T(".maxPrg"));
		}
		if (itr->first == _T("road"))
		{
			// road
			_road rd;

			// link
			rd.link.predecessor.elementType = itr->second.get(_T("link.predecessor..elementType"), _T(""));
			rd.link.predecessor.elementId = itr->second.get(_T("link.predecessor..elementId"), _T(""));
			rd.link.predecessor.cOntactPoint= itr->second.get(_T("link.predecessor..contactPoint"), _T(""));

			rd.link.successor.elementType = itr->second.get(_T("link.predecessor..elementType"), _T(""));
			rd.link.successor.elementId = itr->second.get(_T("link.predecessor..elementId"), _T(""));
			rd.link.successor.cOntactPoint= itr->second.get(_T("link.predecessor..contactPoint"), _T(""));

			// geomeotry
			_geometry geo;
			planView_vec pa_vc;

			_self_type pv_tr = itr->second.get_child(_T("planView"));
			for_each(pv_tr.begin(), pv_tr.end(), [&](const _value_type &_vt)
			{
				rd.elevationProfile.a = _vt.first;
				geo.s = _vt.second.get(_T(".s"), _T(""));
				geo.x = _vt.second.get(_T(".x"), _T(""));
				geo.y = _vt.second.get(_T(".y"), _T(""));
				geo.hdg = _vt.second.get(_T(".hdg"), _T(""));
				geo.length = _vt.second.get(_T(".length"), _T(""));
				pa_vc.push_back(geo);
			});
			rd.planeView = pa_vc;

			// elevationProfile
			rd.elevationProfile.a = itr->second.get(_T("elevationProfile.elevation..a"), _T(""));
			rd.elevationProfile.b = itr->second.get(_T("elevationProfile.elevation..b"), _T(""));
			rd.elevationProfile.c = itr->second.get(_T("elevationProfile.elevation..c"), _T(""));
			rd.elevationProfile.d = itr->second.get(_T("elevationProfile.elevation..d"), _T(""));
			rd.elevationProfile.s = itr->second.get(_T("elevationProfile.elevation..s"), _T(""));

			// superelevation
			_self_type itr_sup = itr->second.get_child(_T("lateralProfile"));
			lateralProfile_vec lat_vc;
			_superelevation sup;
			for_each(itr_sup.begin(), itr_sup.end(), [&](const _value_type &_vt)
			{
				sup.a = _vt.second.get(_T(".a"), _T(""));
				sup.b = _vt.second.get(_T(".b"), _T(""));
				sup.c = _vt.second.get(_T(".c"), _T(""));
				sup.d = _vt.second.get(_T(".d"), _T(""));
				sup.s = _vt.second.get(_T(".s"), _T(""));
				lat_vc.push_back(sup);
			});
			rd.lateralProfile = lat_vc;
			OD_xml.road_vc.push_back(rd);
		}
		else if (itr->first == _T("junction"))
		{
			_junction junc;
			junc.name = itr->second.get(_T(".name"), _T(""));
			junc.id = itr->second.get(_T(".id"), _T(""));
			OD_xml.junction_vc.push_back(junc);
		}
	}
	
	wcout <<_T("OD_XML:") <

命名提示符下的输出: