Question

So I was not at all willing to post it as already there are infinite documents about it. Its been 2years that I touched LINQ and now its taking a dig at me. After 3 hour of continuous try and failures, I decided to do what I was not willing to. Post it to SO.

I have this XML

<TopMost xmlns="http://abc.com/">
    <Mine>MyName</Mine>
    <Hello>
        <File>SIMPLE</File>
        <Book>20</Book>
        <Copy>0</Copy>
    </Hello>
</TopMost>

I just want to get values of “File”, “Book”, “Copy”. and want to compare it with something in Unit Test.

I reached upto this:

string result = string.Empty;
const string path = @"C:\Library.xml";
XDocument xdoc = XDocument.Load(path);

var lv1s = from paper in xdoc.Descendants("Hello")
    select new
        {
            fileP = paper.Element("File").Value,
            bookP = paper.Element("Book").Value,
            copyP = paper.Element("Copy").Value,
        };
result += lv1s.fileP + lv1s.bookP + lv1s.copyP;  // Error
MessageBox.Show(result);

Error: Sequence contains no elements

I know there has to be a easy way around and I am far from it. I have many such code snippets that I have tried and failed.

EDIT

var lv1s = from paper in xdoc.Descendants(ns + "Hello")
    select new
        {
            fileP = paper.Element(ns + "File").Value,
            bookP = paper.Element(ns + "Book").Value,
            copyP = paper.Element(ns + "Copy").Value,
        };

I am getting Compilation error.

Error: The Name ns doex not exist in current context.

Answer 1

You need to specify the namespcae:

XNamespace ns = "http://abc.com/";  // or: doc.Root.GetDefaultNamespace()

var lv1s = from paper in xdoc.Descendants( ns + "Hello")
   select new
        {
            fileP = paper.Element(ns +"File").Value,
            bookP = paper.Element(ns +"Book").Value,
            copyP = paper.Element(ns +"Copy").Value,
        };

Don’t be tempted to use string ns or var ns .