C# 通过LINQ从XML元素生成字典

我正在尝试解析XML文件，并以所需格式获得一些输出

这是我的XML文件格式

<?xml version="1.0" encoding="utf-8" ?>
<Sample>
  <Student name="Tom" id="0" batch="1">
    <Performance>
      <Previous id="1">Marks 1</Previous>
      <Next mid="2">Marks 2</Next>
      <Next mid="3">Marks 3</Next>
    </Performance>
  </Student>
  <Student name="Jerry" id="1" batch="1">
    <Previous mid="1">Marks 4</Previous>
    <Next mid="2">Marks 5</Next>
    <Next mid="3">Marks 6</Next>
    <Next mid="4">Marks 12</Next>
  </Student>
  <Student name="Kate" id="5" batch="2">
    <Previous mid="2">Marks 7</Previous>
    <Previous mid="3">Marks 8</Previous>
    <Next mid="4">Marks 6</Next>
  </Student>
</Sample>

其中0、1、5是学生的ID，相应地是该学生的分数集合

为此，我编写了这个查询，它并没有给出我的输出：
更新（添加查询）

选中此项：

var dictionary = (from student in xElement.Descendants("Student")
                    let marks = student.Descendants()
                         .Where(e => new []{"Previous" ,"Next"}
                              .Contains(e.Name.ToString()))
                    select new {student, marks})
                  .ToDictionary(t => t.student.Attribute("id").Value, 
                                  t => t.marks.Select(mark => new Data {
                                                                       MarkId = mark.Attribute("mid").Value, 
                                                                       MarkName = mark.Value
                                                                        }).ToList());

请注意，您的XML可能有一个错误：

---

除了

标记1

之外，可能还应该有

标记1

请显示到目前为止的查询。@DanielHilgarth:Oops！忘记插入片段了。补充

XDocument xdoc = XDocument.Load("XMLfile1.xml");
            var content = xdoc.Descendants("Student")
                        .Select(st => st.Descendants("Previous")
                        .Union(st.Descendants("Next"))
                        .Select(terms => new Marks { MarksId = terms.Attribute("mid").Value, MarksName = terms.Value })).ToDictionary<Marks, int>(key => key.StudentId) ;

class Marks
    {
        public int StudentID
        {
            get;
            set;
        }
        public string MarksId
        {
            get;
            set;
        }
        public string MarksName
        {
            get;
            set;
        }

var dictionary = (from student in xElement.Descendants("Student")
                    let marks = student.Descendants()
                         .Where(e => new []{"Previous" ,"Next"}
                              .Contains(e.Name.ToString()))
                    select new {student, marks})
                  .ToDictionary(t => t.student.Attribute("id").Value, 
                                  t => t.marks.Select(mark => new Data {
                                                                       MarkId = mark.Attribute("mid").Value, 
                                                                       MarkName = mark.Value
                                                                        }).ToList());