从后代属性xml linq查找父级？

Question

我正在尝试使用子后代属性==值捕获Elements

class Program
{
    static void Main(string[] args)
    {
        XDocument doc = XDocument.Load(@"path to doc");
        var query = from q in doc.Elements("Candidates").Elements("Candidates")
                    //How to filter based on descendant attribute value
                    where (string)q.Descendants("CandidatesPropertyValue")
                    .Attributes["PropertyValue"] != "Consumer Sales & Information"
                    //? this doesn't work obviously
                    select q;
        string type;
        string val;
        foreach (var record in query)
        {
            foreach (XAttribute a in record.Element("Candidates").Attributes())
            {
                Console.WriteLine("{0} = \"{1}\"", a.Name.ToString(), a.Value.ToString());
            }
            foreach (XElement e in record.Descendants())
            {
                type = (string)e.Attribute("PropertyType").Value;
                val = (string)e.Attribute("PropertyValue").Value;
                Console.WriteLine("     {0} = \"{1}\"", type, val);
            }
        }
        Console.ReadLine();
    }

<CandidatesRoot>
      I WANT THIS ELEMENT
- <Candidates ...bunch of attributes...>
  <CandidatesPropertyValue PropertyType="Type1" PropertyValue="Value1" /> 
  <CandidatesPropertyValue PropertyType="Type2" PropertyValue="Value2" /> 
  <CandidatesPropertyValue PropertyType="Type3" PropertyValue="Value3" /> 
  <CandidatesPropertyValue PropertyType="Type4" PropertyValue="Value4" /> 
  <CandidatesPropertyValue PropertyType="Type5" PropertyValue="Value5" /> 
  </Candidates>
      BUT I DON'T WANT THIS ONE
- <Candidates ...bunch of attributes...>
  <CandidatesPropertyValue PropertyType="Type1" PropertyValue="Value1" />
  <CandidatesPropertyValue PropertyType="LineOfBusiness" PropertyValue="Consumer Sales & Information" />
  <CandidatesPropertyValue PropertyType="Type2" PropertyValue="Value2" /> 
  <CandidatesPropertyValue PropertyType="Type3" PropertyValue="Value3" /> 
  <CandidatesPropertyValue PropertyType="Type4" PropertyValue="Value4" /> 
  <CandidatesPropertyValue PropertyType="Type5" PropertyValue="Value5" /> 
  </Candidates>

Answer 1

您可以使用XPath

using System.Xml.XPath;

...
String val = "\"Consumer Sales & Information\"";
String xpath = String.Format(".//CandidatesPropertyValue[@PropertyValue= {0}]", val);
doc.XPathSelectElements(xpath);

Answer 2

我要冒险猜测，说您需要将其更改为：

where (string)q.Descendants("CandidatesPropertyValue")
    .Attributes("PropertyValue").SingleOrDefault()

如果它需要至少一个没有该值的后代：

where q.Descendants("CandidatesPropertyValue")
    .Attributes("PropertyValue")
    .Any(a => a.Value != "Consumer Sales & Information")

Answer 3

此举旨在命名的所有元素Candidates谁拥有一个名为至少一个后代CandidatesPropertyValue名为至少一个属性PropertyValue与价值"Consumer Sales & Information" ：

var query = from q in doc.Elements("Candidates").Elements("Candidates")
            where q.Descendants("CandidatesPropertyValue")
                   .Any(p => p.Attributes("PropertyValue")
                       .Any(a => a.Value == "Consumer Sales & Information"))
            select q;