如何使用DescendantsUntil()提取XML中多层嵌套的Member元素？

之前使用DescendantsUntil()扩展方法仅能定位顶层<Member>元素及其直接子元素，现在需要处理多层嵌套的XML结构，提取所有层级的<Member>元素（包括父级、子级、孙级等所有嵌套的Member节点）。

示例XML结构 #

<?xml version="1.0" encoding="utf-8"?>
<Document>
    <Interface>
        <Sections xmlns="http://www.siemens.com/automation/Openness/SW/Interface/v4">
            <Section Name="Static">
                <Member Name="3bool1" Datatype="&quot;3bool&quot;" Remanence="NonRetain" Accessibility="Public">
                    <AttributeList>
                        <BooleanAttribute Name="ExternalAccessible" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="ExternalVisible" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="ExternalWritable" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="SetPoint" SystemDefined="true">false</BooleanAttribute>
                    </AttributeList>
                    <Sections>
                        <Section Name="None">
                            <Member Name="bool1" Datatype="Bool" />
                            <Member Name="bool2" Datatype="Bool" />
                            <Member Name="bool3" Datatype="Bool" />
                            <Member Name="3bool1" Datatype="&quot;3bool&quot;" Remanence="NonRetain" Accessibility="Public">
                                <AttributeList>
                                    <BooleanAttribute Name="ExternalAccessible" SystemDefined="true">true</BooleanAttribute>
                                    <BooleanAttribute Name="ExternalVisible" SystemDefined="true">true</BooleanAttribute>
                                    <BooleanAttribute Name="ExternalWritable" SystemDefined="true">true</BooleanAttribute>
                                    <BooleanAttribute Name="SetPoint" SystemDefined="true">false</BooleanAttribute>
                                </AttributeList>
                                <Sections>
                                    <Section Name="None">
                                        <Member Name="bool1" Datatype="Bool" />
                                        <Member Name="bool2" Datatype="Bool" />
                                        <Member Name="bool3" Datatype="Bool" />
                                    </Section>
                                </Sections>
                            </Member>
                        </Section>
                    </Sections>
                </Member>
                <Member Name="int7" Datatype="Int" Remanence="NonRetain" Accessibility="Public">
                    <AttributeList>
                        <BooleanAttribute Name="ExternalAccessible" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="ExternalVisible" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="ExternalWritable" SystemDefined="true">true</BooleanAttribute>
                        <BooleanAttribute Name="SetPoint" SystemDefined="true">true</BooleanAttribute>
                    </AttributeList>
                </Member>
            </Section>
        </Sections>
    </Interface>
 </Document>

原代码（仅提取顶层Member） #

string path = ("C:\\Users\\");
XDocument doc = XDocument.Load(path + "File.xml");
XNamespace ns = "http://www.siemens.com/automation/Openness/SW/Interface/v4";
XName name = ns + "Member";

var memb = doc
    .Root.DescendantsUntil(e => e.Name == name)
    .Select(e => (Parent: e, Children: e.DescendantsUntil(c => c.Name == name).ToList()))
    //.Where(i => i.Children.Count > 0); // Uncomment to filter out <Member> elements with no child members.
    .ToList();

解决方案：提取所有层级的Member #

要覆盖所有嵌套层级的<Member>元素，只需先通过Descendants(memberName)遍历整个XML树获取所有<Member>节点，再对每个节点用DescendantsUntil()提取其直接子Member即可。修改后的代码如下：

string path = @"C:\Users\";
XDocument doc = XDocument.Load(path + "File.xml");
XNamespace ns = "http://www.siemens.com/automation/Openness/SW/Interface/v4";
XName memberName = ns + "Member";

// 获取所有层级的Member元素，每个元素包含自身和它的直接子Member集合
var allMembers = doc
    .Descendants(memberName)
    .Select(member => (
        Parent: member,
        Children: member.DescendantsUntil(child => child.Name == memberName).ToList()
    ))
    .ToList();

关键说明 #

• doc.Descendants(memberName)：遍历整个XML文档，返回所有层级的<Member>元素，包括嵌套在其他Member内部的节点。
• member.DescendantsUntil(child => child.Name == memberName)：对每个Member节点，提取其下一层级的直接子Member（不会深入到子Member的子节点）。
• 如果需要过滤掉没有子Member的节点，只需取消注释.Where(i => i.Children.Count > 0)即可。

内容的提问来源于stack exchange，提问作者fabrizio scarpetta