获取 XElement 的 XPath? [英] Get the XPath to an XElement?
本文介绍了获取 XElement 的 XPath?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我在文档深处有一个 XElement.鉴于 XElement(和 XDocument?),是否有扩展方法来获取其完整(即绝对,例如 /root/item/element/child
)XPath?
I've got an XElement deep within a document. Given the XElement (and XDocument?), is there an extension method to get its full (i.e. absolute, e.g. /root/item/element/child
) XPath?
例如myXElement.GetXPath()?
E.g. myXElement.GetXPath()?
好吧,看来我忽略了一些很重要的事情.哎呀!需要考虑元素的索引.请参阅我对建议的更正解决方案的最后回答.
推荐答案
扩展方法:
public static class XExtensions
{
/// <summary>
/// Get the absolute XPath to a given XElement
/// (e.g. "/people/person[6]/name[1]/last[1]").
/// </summary>
public static string GetAbsoluteXPath(this XElement element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
Func<XElement, string> relativeXPath = e =>
{
int index = e.IndexPosition();
string name = e.Name.LocalName;
// If the element is the root, no index is required
return (index == -1) ? "/" + name : string.Format
(
"/{0}[{1}]",
name,
index.ToString()
);
};
var ancestors = from e in element.Ancestors()
select relativeXPath(e);
return string.Concat(ancestors.Reverse().ToArray()) +
relativeXPath(element);
}
/// <summary>
/// Get the index of the given XElement relative to its
/// siblings with identical names. If the given element is
/// the root, -1 is returned.
/// </summary>
/// <param name="element">
/// The element to get the index of.
/// </param>
public static int IndexPosition(this XElement element)
{
if (element == null)
{
throw new ArgumentNullException("element");
}
if (element.Parent == null)
{
return -1;
}
int i = 1; // Indexes for nodes start at 1, not 0
foreach (var sibling in element.Parent.Elements(element.Name))
{
if (sibling == element)
{
return i;
}
i++;
}
throw new InvalidOperationException
("element has been removed from its parent.");
}
}
和测试:
class Program
{
static void Main(string[] args)
{
Program.Process(XDocument.Load(@"C: est.xml").Root);
Console.Read();
}
static void Process(XElement element)
{
if (!element.HasElements)
{
Console.WriteLine(element.GetAbsoluteXPath());
}
else
{
foreach (XElement child in element.Elements())
{
Process(child);
}
}
}
}
和示例输出:
/tests/test[1]/date[1]
/tests/test[1]/time[1]/start[1]
/tests/test[1]/time[1]/end[1]
/tests/test[1]/facility[1]/name[1]
/tests/test[1]/facility[1]/website[1]
/tests/test[1]/facility[1]/street[1]
/tests/test[1]/facility[1]/state[1]
/tests/test[1]/facility[1]/city[1]
/tests/test[1]/facility[1]/zip[1]
/tests/test[1]/facility[1]/phone[1]
/tests/test[1]/info[1]
/tests/test[2]/date[1]
/tests/test[2]/time[1]/start[1]
/tests/test[2]/time[1]/end[1]
/tests/test[2]/facility[1]/name[1]
/tests/test[2]/facility[1]/website[1]
/tests/test[2]/facility[1]/street[1]
/tests/test[2]/facility[1]/state[1]
/tests/test[2]/facility[1]/city[1]
/tests/test[2]/facility[1]/zip[1]
/tests/test[2]/facility[1]/phone[1]
/tests/test[2]/info[1]
那应该可以解决这个问题.不?
That should settle this. No?
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