XDocument, XElement : Sequence contains no matching element

Question

Searching element of xml file using C# but getting following

Error: Sequence contains no matching element

    XNamespace siteNM = "http://schemas.microsoft.com/AspNet/SiteMap-File-1.0";
            XDocument sitemap = new XDocument
                (new XDeclaration("1.0", "UTF-8", null), 
                     new XElement(siteNM + "siteMap", 
                          new XElement(siteNM + "siteMapNode", new XAttribute("title", "Home"), new XAttribute("url", "home.aspx"), new XAttribute("description", "Home"))
                                 ));
    XElement x = sitemap.Root;

I have tried following two methods for searching element but both give me same error .

1st way:

XElement child = x.Descendants("siteMapNode").Where(el => el.Attribute("title") != null && el.Attribute("title").Value == "Home").First();

2nd Way:

XElement child1 = x.Descendants("siteMapNode").First(el => (string)el.Attribute("title") == "Home");

please help me. Thank you so much..

Answer 1

missing namespace

XElement child = x.Descendants(siteNM + "siteMapNode")
                .First(el => el.Attribute("title") != null && el.Attribute("title").Value == "Home");

Answer 2

你可能也应该在搜索查询中添加namespece：

XElement child = x.Descendants(siteNM + "siteMapNode").Where(el => el.Attribute("title") != null && el.Attribute("title").Value == "Home").First();