请问一下C# linq 查询 如何查询一个节点下的子节点

Question

<?xml version="1.0" encoding="utf-8" ?>
<note>
  <Student>
    <Name>li</Name>
    <ID>123</ID>
    <WorkName>assignment1</WorkName>
    <Grade>80</Grade>
  </Student>
  <Student>
    <Name>han</Name>
    <ID>158</ID>
    <WorkName>assignment2</WorkName>
    <Grade>80</Grade>
    <question>
  <index>1</index>
  <score>100</score>
    </question> 
  </Student>
</note>
就例如我的xml是这样的，我现在能查询Student下的Name, ID, WorkName, Grade.
但是我想查询question的index=1情况下，在Datagridview里显示出score的值要怎么样写呢
 public void Query(String GradeResult, String NameResult, String IDResult, String WorkNameResult)
        {
            XElement xelement = XElement.Load("E:/WindowsFormsApplication1Update2/WindowsFormsApplication1/WindowsFormsApplication1/1.xml");            
            var query = from t in xelement.Descendants("Student")                    //located in "Student" root
                       .Where(w => w.Element("Grade").Value.Contains(GradeResult))   //use "where" which contain the keyword to select the result
                       .Where(w => w.Element("Name").Value.Contains(NameResult))
                       .Where(w => w.Element("ID").Value.Contains(IDResult))
                       .Where(w => w.Element("WorkName").Value.Contains(WorkNameResult))
                        
                        select new
                        {
                            Name = t.Element("Name").Value,
                            ID = t.Element("ID").Value,
                            WorkName = t.Element("WorkName").Value,
                            Grade = t.Element("Grade").Value,
                            Index = t.Element("question").Element("index").Value,                           
                           
                        };                        dataGridView1.DataSource = query.ToList();
        }

Answer 1

或许这就是你要的答案吧，有两种方式都可行var xml = XDocument.Parse(@"<note>
  <Student>
    <Name>li</Name>
    <ID>123</ID>
    <WorkName>assignment1</WorkName>
    <Grade>80</Grade>
  </Student>
  <Student>
    <Name>han</Name>
    <ID>158</ID>
    <WorkName>assignment2</WorkName>
    <Grade>80</Grade>
    <question>
          <index>1</index>
          <score>100</score>
    </question> 
  </Student>
  <Student>
    <Name>yan</Name>
    <ID>156</ID>
    <WorkName>assignment5</WorkName>
    <Grade>88</Grade>
    <question>
          <index>2</index>
          <score>101</score>
    </question> 
  </Student>
</note>");var note = xml.Root;
var students = note.Elements();//因为有些节点没有question子节点，所以需要判断父节点是否为null
var query = students
    .Where(x => x.Element("question") != null && x.Element("question").Element("index").Value == "1")
    .Select(t => new
    {
        Name = t.Element("Name").Value,
        ID = t.Element("ID").Value,
        WorkName = t.Element("WorkName").Value,
        Grade = t.Element("Grade").Value,
        Index = t.Element("question").Element("index").Value,
    }).ToList();;var query2 = (from t in note.Elements()
             .Where(x => x.Element("question") != null && x.Element("question").Element("index").Value == "1")
              select new
              {
                  Name = t.Element("Name").Value,
                  ID = t.Element("ID").Value,
                  WorkName = t.Element("WorkName").Value,
                  Grade = t.Element("Grade").Value,
                  Index = t.Element("question").Element("index").Value,
              }).ToList();

Answer 2

这个问题我只能让百度告诉你
https://bbs.csdn.net/topics/390893718

Answer 3

static void Main(string[] args)
        {
            string data = @"<?xml version='1.0' encoding='utf-8' ?>
                <note>
  <Student>
    <Name>li</Name>
    <ID>123</ID>
    <WorkName>assignment1</WorkName>
    <Grade>80</Grade>
  </Student>
  <Student>
    <Name>han</Name>
    <ID>158</ID>
    <WorkName>assignment2</WorkName>
    <Grade>80</Grade>
    <question>
          <index>1</index>
          <score>100</score>
    </question> 
  </Student>
</note>";
            XElement xelement = XElement.Parse(data);
            var q = (from t in xelement.Descendants("Student")
                    let question = t.Element("question")
                    select new
                        {
                            Name = t.Element("Name").Value,
                            ID = t.Element("ID").Value,
                            WorkName = t.Element("WorkName").Value,
                            Grade = t.Element("Grade").Value,
                            Index = question==null?"":(question.Element("index").Value),
                            Score = question==null?"":(question.Element("index").Value=="1"?question.Element("score").Value:"0")
                        }).ToList();            Console.ReadLine();        }