c++ - 为什么 boost::property_tree::read_xml 抛出读取有效的 Office Open XML？

Question

我正在使用 Boost 1.62.0 并尝试根据 the ISO standard 解析一个 Excel .xlsx 文件包含各种 XML 文件。它读取 [Content_Types].xml 文件就好了。但是对于我试图读取的第二个 (workbook.xml.rels) 和第三个 (workbook.xml) 文件，它会引发如下异常:

/usr/local/include/boost/property_tree/detail/xml_parser_read_rapidxml.hpp(138): Throw in function void boost::property_tree::xml_parser::read_xml_internal(std::basic_istream<typename Ptree::key_type::value_type> &, Ptree &, int, const std::string &) [Ptree = boost::property_tree::basic_ptree<std::__1::basic_string<char>, std::__1::basic_string<char>, std::__1::less<std::__1::basic_string<char> > >]
Dynamic exception type: boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::property_tree::xml_parser::xml_parser_error> >
std::exception::what: ../tmp/UX0s9R9kBpSxFB40s9OTzTD9/xl/_rels/workbook.xml.rels(1): expected <

这里是/xl/_rels/workbook.xml.rels(默认缩小):

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId8" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet8.xml"/><Relationship Id="rId13" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet13.xml"/><Relationship Id="rId18" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/theme" Target="theme/theme1.xml"/><Relationship Id="rId3" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet3.xml"/><Relationship Id="rId7" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet7.xml"/><Relationship Id="rId12" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet12.xml"/><Relationship Id="rId17" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet17.xml"/><Relationship Id="rId2" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet2.xml"/><Relationship Id="rId16" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet16.xml"/><Relationship Id="rId20" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings" Target="sharedStrings.xml"/><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet1.xml"/><Relationship Id="rId6" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet6.xml"/><Relationship Id="rId11" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet11.xml"/><Relationship Id="rId5" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet5.xml"/><Relationship Id="rId15" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet15.xml"/><Relationship Id="rId10" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet10.xml"/><Relationship Id="rId19" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles" Target="styles.xml"/><Relationship Id="rId4" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet4.xml"/><Relationship Id="rId9" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet9.xml"/><Relationship Id="rId14" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet14.xml"/></Relationships>

和/xl/workbook.xml:

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"><fileVersion appName="xl" lastEdited="5" lowestEdited="5" rupBuild="9302"/><workbookPr defaultThemeVersion="124226"/><bookViews><workbookView xWindow="360" yWindow="420" windowWidth="24675" windowHeight="11805" firstSheet="3" activeTab="16"/></bookViews><sheets><sheet name="Sheet1" sheetId="1" r:id="rId1"/><sheet name="Sheet2" sheetId="2" r:id="rId2"/><sheet name="Sheet3" sheetId="3" r:id="rId3"/><sheet name="Sheet4" sheetId="4" r:id="rId4"/><sheet name="Sheet5" sheetId="5" r:id="rId5"/><sheet name="Sheet6" sheetId="6" r:id="rId6"/><sheet name="Sheet7" sheetId="7" r:id="rId7"/><sheet name="Sheet8" sheetId="8" r:id="rId8"/><sheet name="Sheet9" sheetId="9" r:id="rId9"/><sheet name="Sheet10" sheetId="10" r:id="rId10"/><sheet name="Sheet11" sheetId="11" r:id="rId11"/><sheet name="Sheet12" sheetId="12" r:id="rId12"/><sheet name="Sheet13" sheetId="13" r:id="rId13"/><sheet name="Sheet14" sheetId="14" r:id="rId14"/><sheet name="Sheet15" sheetId="15" r:id="rId15"/><sheet name="Sheet16" sheetId="16" r:id="rId16"/><sheet name="Sheet17" sheetId="17" r:id="rId17"/></sheets><calcPr calcId="144525"/></workbook>

我已经使用各种在线 XML 验证器验证了 XML，并且它通过了所有验证器。知道为什么 boost::property_tree::read_xml 在第一行需要一个 '<' 吗？

Answer 1

好的，我从boost documentation找到了答案:

Unfortunately, there is no XML parser in Boost as of the time of this writing. The library therefore contains the fast and tiny RapidXML parser (currently in version 1.13) to provide XML parsing support. RapidXML does not fully support the XML standard; it is not capable of parsing DTDs and therefore cannot do full entity substitution.

所以，看来我必须使用另一个 XML 解析器。