Linq to XML取回存在于不同级别上的属性

<root>
  <element1 attribute1="value1">
    <element2 attribute2="value2">
      <element3 attribute3="value3" />
    </element2>
  </element1>
</root>

XDocument doc = XDocument.Load("path/to/xml/file.xml");

// 使用LINQ查询语法
var attributes = from element1 in doc.Descendants("element1")
                 from element2 in element1.Descendants("element2")
                 from element3 in element2.Descendants("element3")
                 select new
                 {
                     Attribute1 = (string)element1.Attribute("attribute1"),
                     Attribute2 = (string)element2.Attribute("attribute2"),
                     Attribute3 = (string)element3.Attribute("attribute3")
                 };

// 使用方法链
var attributes = doc.Descendants("element1")
                    .SelectMany(element1 => element1.Descendants("element2"))
                    .SelectMany(element2 => element2.Descendants("element3"))
                    .Select(element3 => new
                    {
                        Attribute1 = (string)element3.Ancestors("element1").First().Attribute("attribute1"),
                        Attribute2 = (string)element3.Ancestors("element2").First().Attribute("attribute2"),
                        Attribute3 = (string)element3.Attribute("attribute3")
                    });

foreach (var attribute in attributes)
{
    Console.WriteLine($"Attribute1: {attribute.Attribute1}");
    Console.WriteLine($"Attribute2: {attribute.Attribute2}");
    Console.WriteLine($"Attribute3: {attribute.Attribute3}");
}