Why Does My LINQ to XML Query Return Null When Using XML Namespaces?

Solve the problem of XML namespace in LINQ to XML causing empty query results

This article discusses the problem of query results returning null when using LINQ to XML to process XML data containing XML namespaces. The code is designed to extract data from XML, but the query fails due to improper use of namespaces.

LINQ to XML's Descendants and Element methods receive XName parameters. Although using strings directly instead of XName objects can automatically convert them, it is error-prone. To solve this problem, you need to explicitly specify the namespace using a XNamespace instance before using the string representation of the element name:

<code class="language-csharp">XNamespace ns = "http://myvalue.com";
XNamespace nsa = "http://schemas.datacontract.org/2004/07/My.Namespace";

var elements = from data in xmlElements.Descendants(ns + "Result")
               select new
               {
                   TheBool = (bool)data.Element(nsa + "TheBool"),
                   TheId = (int)data.Element(nsa + "TheId"),
               };</code>

Please note that Descendants is used in the ns method and Element is used in the nsa method. By explicitly defining the namespace, you can ensure that the target element is correct, thus solving the problem of Descendants returning null.

The above is the detailed content of Why Does My LINQ to XML Query Return Null When Using XML Namespaces?. For more information, please follow other related articles on the PHP Chinese website!