Question

It doesnt matter what I write in the Equals method. The GetHashCode is always fired, but I do not know whose GetHashCode to return?

When the GetHashCode method is called then variable x has the following data:

In the first unitName elementName is the value “This is the value I want to compare” …

<unit>
  <unitName>This is the value I want to compare</unitName>
  <units>
    <unit>
      <unitName>xxx</unitName>      
      <units>
        <unit>
          <unitName>cccc</unitName>
          <test>33</test>
          <test>44</test>                   
        </unit>
      </units>          
        </unit>
    </units>        
</unit>

IEnumerable<XElement> tempMemberList = doc.Elements("dep").Descendants("customers").Distinct(new XElementComparer());

public class XElementComparer : IEqualityComparer<XElement> {
    public bool Equals(XElement x, XElement y) {

        return x.Value == y.Value;
    }

    public int GetHashCode(XElement x) {
        return x.GetHashCode();
    }
}

Answer 1

This is the solution, I just had to get the proper value from the first unitName I wanted…

public class XElementComparer : IEqualityComparer<XElement>
        {
            public bool Equals(XElement x, XElement y)
            {
                string unitNameX = x.Element("unitName ").Value;
                string unitNameY = y.Element("unitName ").Value;
                return unitNameX == unitName Y;
            }

            public int GetHashCode(XElement x)
            {
                string val = x.Element("unitName ").Value;
                return val.GetHashCode();
            }
        }