c# - 从 xsd 架构中提取 XPath

Question

想知道这是否可能!!

仅给定一个 xsd 模式是否可以提取所有 xpath？

使用 c#，我使用 linq to xml 将 xsdSchema 加载到 XDocument 中，然后我必须提取所有 xpath。

在网上找了找也没找到!

Answer 1

有一个MSDN article on how to do this

---

文章中的代码总结如下:

This example shows an function named GetXPath that generates a specific XPath expression for any node in the XML tree. It generates appropriate XPath expressions even when nodes are in a namespace. The XPath expressions are generated by using namespace prefixes.

public static class MyExtensions
{
    private static string GetQName(XElement xe)
    {
        string prefix = xe.GetPrefixOfNamespace(xe.Name.Namespace);
        if (xe.Name.Namespace == XNamespace.None || prefix == null)
            return xe.Name.LocalName.ToString();
        else
            return prefix + ":" + xe.Name.LocalName.ToString();
    }

    private static string GetQName(XAttribute xa)
    {
        string prefix =
            xa.Parent.GetPrefixOfNamespace(xa.Name.Namespace);
        if (xa.Name.Namespace == XNamespace.None || prefix == null)
            return xa.Name.ToString();
        else
            return prefix + ":" + xa.Name.LocalName;
    }

    private static string NameWithPredicate(XElement el)
    {
        if (el.Parent != null && el.Parent.Elements(el.Name).Count() != 1)
            return GetQName(el) + "[" +
                (el.ElementsBeforeSelf(el.Name).Count() + 1) + "]";
        else
            return GetQName(el);
    }

    public static string StrCat<T>(this IEnumerable<T> source,
        string separator)
    {
        return source.Aggregate(new StringBuilder(),
                   (sb, i) => sb
                       .Append(i.ToString())
                       .Append(separator),
                   s => s.ToString());
    }

    public static string GetXPath(this XObject xobj)
    {
        if (xobj.Parent == null)
        {
            XDocument doc = xobj as XDocument;
            if (doc != null)
                return ".";
            XElement el = xobj as XElement;
            if (el != null)
                return "/" + NameWithPredicate(el);
            // the XPath data model does not include white space text nodes
            // that are children of a document, so this method returns null.
            XText xt = xobj as XText;
            if (xt != null)
                return null;
            XComment com = xobj as XComment;
            if (com != null)
                return
                    "/" +
                    (
                        com
                        .Document
                        .Nodes()
                        .OfType<XComment>()
                        .Count() != 1 ?
                        "comment()[" +
                        (com
                        .NodesBeforeSelf()
                        .OfType<XComment>()
                        .Count() + 1) +
                        "]" :
                        "comment()"
                    );
            XProcessingInstruction pi = xobj as XProcessingInstruction;
            if (pi != null)
                return
                    "/" +
                    (
                        pi.Document.Nodes()
                        .OfType<XProcessingInstruction>()
                        .Count() != 1 ?
                        "processing-instruction()[" +
                        (pi
                        .NodesBeforeSelf()
                        .OfType<XProcessingInstruction>()
                        .Count() + 1) +
                        "]" :
                        "processing-instruction()"
                    );
            return null;
        }
        else
        {
            XElement el = xobj as XElement;
            if (el != null)
            {
                return
                    "/" +
                    el
                    .Ancestors()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    NameWithPredicate(el);
            }
            XAttribute at = xobj as XAttribute;
            if (at != null)
                return
                    "/" +
                    at
                    .Parent
                    .AncestorsAndSelf()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    "@" + GetQName(at);
            XComment com = xobj as XComment;
            if (com != null)
                return
                    "/" +
                    com
                    .Parent
                    .AncestorsAndSelf()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    (
                        com
                        .Parent
                        .Nodes()
                        .OfType<XComment>()
                        .Count() != 1 ?
                        "comment()[" +
                        (com
                        .NodesBeforeSelf()
                        .OfType<XComment>()
                        .Count() + 1) + "]" :
                        "comment()"
                    );
            XCData cd = xobj as XCData;
            if (cd != null)
                return
                    "/" +
                    cd
                    .Parent
                    .AncestorsAndSelf()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    (
                        cd
                        .Parent
                        .Nodes()
                        .OfType<XText>()
                        .Count() != 1 ?
                        "text()[" +
                        (cd
                        .NodesBeforeSelf()
                        .OfType<XText>()
                        .Count() + 1) + "]" :
                        "text()"
                    );
            XText tx = xobj as XText;
            if (tx != null)
                return
                    "/" +
                    tx
                    .Parent
                    .AncestorsAndSelf()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    (
                        tx
                        .Parent
                        .Nodes()
                        .OfType<XText>()
                        .Count() != 1 ?
                        "text()[" +
                        (tx
                        .NodesBeforeSelf()
                        .OfType<XText>()
                        .Count() + 1) + "]" :
                        "text()"
                    );
            XProcessingInstruction pi = xobj as XProcessingInstruction;
            if (pi != null)
                return
                    "/" +
                    pi
                    .Parent
                    .AncestorsAndSelf()
                    .InDocumentOrder()
                    .Select(e => NameWithPredicate(e))
                    .StrCat("/") +
                    (
                        pi
                        .Parent
                        .Nodes()
                        .OfType<XProcessingInstruction>()
                        .Count() != 1 ?
                        "processing-instruction()[" +
                        (pi
                        .NodesBeforeSelf()
                        .OfType<XProcessingInstruction>()
                        .Count() + 1) + "]" :
                        "processing-instruction()"
                    );
            return null;
        }
    }
}

class Program
{
    static void Main(string[] args)
    {
        XNamespace aw = "http://www.adventure-works.com";
        XDocument doc = new XDocument(
            new XDeclaration("1.0", "utf-8", "yes"),
            new XProcessingInstruction("target", "data"),
            new XElement("Root",
                new XAttribute("AttName", "An Attribute"),
                new XAttribute(XNamespace.Xmlns + "aw", aw.ToString()),
                new XComment("This is a comment"),
                new XElement("Child",
                    new XText("Text")
                ),
                new XElement("Child",
                    new XText("Other Text")
                ),
                new XElement("ChildWithMixedContent",
                    new XText("text"),
                    new XElement("b", "BoldText"),
                    new XText("otherText")
                ),
                new XElement(aw + "ElementInNamespace",
                    new XElement(aw + "ChildInNamespace")
                )
            )
        );
        doc.Save("Test.xml");
        Console.WriteLine(File.ReadAllText("Test.xml"));
        Console.WriteLine("------");
        foreach (XObject obj in doc.DescendantNodes())
        {
            Console.WriteLine(obj.GetXPath());
            XElement el = obj as XElement;
            if (el != null)
                foreach (XAttribute at in el.Attributes())
                    Console.WriteLine(at.GetXPath());
        }
    }
}