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

 <Config>

     <Item name="IP测试报告2017-10-24 09-54-31">

         <ChildItem name="Date" desc="" datatype ="string">2017-10-24 09-54-31</ChildItem>

         <ChildItem name="FailureCount" desc="" datatype ="int">1</ChildItem>

         <ChildItem name="IPAddressCount" desc="" datatype ="int">4</ChildItem>

         <ChildItem name="SuccessCount" desc="" datatype ="int">3</ChildItem>

     </Item>

 </Config>

  for (map<wstring, map<wstring, HistoryData>>::iterator it = vect_str.begin(); it != vect_str.end(); it++)

        { //迭代vector

            for (map<wstring, HistoryData>::iterator it1 = it->second.begin(); it1 != it->second.end(); it1++)

            {

                m_pt3.add(L"<xmlattr>.name", it1->second.name);

                m_pt3.add(L"<xmlattr>.desc", it1->second.desc);

                m_pt3.add(L"<xmlattr>.datatype ", it1->second.datatype);

                m_pt3.put_value(it1->second.value);

                m_pt2.add_child(L"ChildItem", m_pt3);

                m_pt3.clear();

            }

            m_pt1.add_child(L"Item", m_pt2);

            m_pt1.add(L"Item.<xmlattr>.name", it->first);

            m_pt2.clear();
        }

        m_pt.add_child(L"Config", m_pt1);   
    auto settings = boost::property_tree::xml_writer_make_settings<std::wstring>(L'\t', 1);
    write_xml(fileName, m_pt, utf8Locale, settings);   

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

<Config>

    <Item name="IP测试报告2017-10-24 09-54-31">

        <ChildItem name="Date" desc="" datatype="string">2017-10-24 09-54-31</ChildItem>

        <ChildItem name="FailureCount" desc="" datatype="int">1</ChildItem>

        <ChildItem name="IPAddressCount" desc="" datatype="int">4</ChildItem>

        <ChildItem name="SuccessCount" desc="" datatype="int">3</ChildItem>

    </Item>

    <Item name="IP测试报告2017-10-24 09-54-32">

        <ChildItem name="Date" desc="" datatype ="string">2017-10-24 09-54-32</ChildItem>

        <ChildItem name="FailureCount" desc="" datatype ="int">1</ChildItem>

        <ChildItem name="IPAddressCount" desc="" datatype ="int">4</ChildItem>

        <ChildItem name="SuccessCount" desc="" datatype ="int">3</ChildItem>

    </Item>

</Config>

 if (auto firstChild = m_pt.get_child_optional(L"Config"))

    {

        m_pt4 = m_pt.get_child(L"Config");

        m_pt.clear();

        for (map<wstring, map<wstring, HistoryData>>::iterator it = vect_str.begin(); it != vect_str.end(); it++)

        { //迭代vector

            for (map<wstring, HistoryData>::iterator it1 = it->second.begin(); it1 != it->second.end(); it1++)

            {

                m_pt3.add(L"<xmlattr>.name", it1->second.name);

                m_pt3.add(L"<xmlattr>.desc", it1->second.desc);

                m_pt3.add(L"<xmlattr>.datatype ", it1->second.datatype);

                m_pt3.put_value(it1->second.value);

                m_pt2.add_child(L"ChildItem", m_pt3)；

                m_pt3.clear();

            }

            m_pt2.add(L"<xmlattr>.name", it->first);

            m_pt4.add_child(L"Item", m_pt2);

            m_pt2.clear();

        }

        m_pt.add_child(L"Config", m_pt4);

    }

    else

    {

        for (map<wstring, map<wstring, HistoryData>>::iterator it = vect_str.begin(); it != vect_str.end(); it++)

        { //迭代vector

            for (map<wstring, HistoryData>::iterator it1 = it->second.begin(); it1 != it->second.end(); it1++)

            {

                m_pt3.add(L"<xmlattr>.name", it1->second.name);

                m_pt3.add(L"<xmlattr>.desc", it1->second.desc);

                m_pt3.add(L"<xmlattr>.datatype ", it1->second.datatype);

                m_pt3.put_value(it1->second.value);

                m_pt2.add_child(L"ChildItem", m_pt3);

                m_pt3.clear();

            }

            m_pt1.add_child(L"Item", m_pt2);

            m_pt1.add(L"Item.<xmlattr>.name", it->first);

            m_pt2.clear();

        }

        m_pt.add_child(L"Config", m_pt1);

    }

    auto settings = boost::property_tree::xml_writer_make_settings<std::wstring>(L'\t', );

    write_xml(fileName, m_pt, utf8Locale, settings);