Select Xml Node using Linq to XML

c#, lambda, linq-to-xml, xml

Solution

Your problem is that `Descendents` and `Where` return an `IEnumerable<XElement>` not a single `XElement` which is what you're after. You can fix this like this:

XElement toEdit = doc.Descendants("ArrayOfCustomer")
                     .Descendants("Customer")
                     .Where(x => Guid.Parse(x.Descendants("CustomerId").Single().Value) == customer.CustomerId)
                     .FirstOrDefault();

Problem

my Xml file : ``` <?xml version="1.0" encoding="utf-8"?> <ArrayOfCustomer xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> <Customer> <CustomerId>1f323c97-2015-4a3d-9956-a93115c272ea</CustomerId> <FirstName>Aria</FirstName> <LastName>Stark</LastName> <DOB>1999-01-01T00:00:00</DOB> </Customer> <Customer> <CustomerId>c9c326c2-1e27-440b-9b25-c79b1d9c80ed</CustomerId> <FirstName>John</FirstName> <LastName>Snow</LastName> <DOB>1983-01-01T00:00:00</DOB> </Customer> </ArrayOfCustomer> ``` my attempt : ``` XElement toEdit = (XElement)doc.Descendants("ArrayOfCustomer") .Descendants("Customer") .Where(x => Guid.Parse((x.Descendants("CustomerId") as XElement).Value) == customer.CustomerId) .First<XElement>(); ``` this throws the following exception : ``` Object reference not set to an instance of an object. ``` 1) isn't `x` an `XElement`? 2) is this a proper where lambda for selecting an Xml node? 3) and of course how would you find this node according to `CustomerId`?

Original source