How to check if first XML node exist?

Question

I have the following XML:

<Root><Node1>node1 value</Node1><Node2>node2 value</Node2></Root>

I'd like to check if Root is the first node. If so, I then want to get the values for the to child nodes.

This XML is inside of an XElement. I've tried this:

xml.Element("Root")

but that returns null. If Root exist, shouldn't it return a non null value?

How about defining an XML schema and validating your XML document? — Alex, Nov 17 '16 at 01:28

mybirthname · Answer 1 · 2016-11-16T23:47:22.363

0

        string xml = @"<Root><Node1>node1 value</Node1><Node2>node2 value</Node2></Root>";

        XDocument doc = XDocument.Parse(xml);

        var root = doc.Root;
        if(root.Name == "Root")
        {
            foreach(var el in root.Descendants())
            {
               string nodeValue = el.Value;
            }

        }

You can check the name of the Root element from Root.Name. After that loop all elements in the root using doc.Root.Descendants().

edited Nov 16 '16 at 23:47

answered Nov 16 '16 at 23:28

mybirthname

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My XML is in an XElement. Are you saying I'll need to put it into an XDocument? – 4thSpace Nov 16 '16 at 23:53
@4thSpace I don't know your exact case. But if this is the whole xml document you should put it in XDocument. – mybirthname Nov 16 '16 at 23:55

score 0 · Answer 2 · answered Nov 17 '16 at 00:59

Since xml is an instance of XElement, it already references the root element, which in this case named Root. Doing xml.Element("Root") will return result only if the <Root> element has another child <Root>.

I'd like to check if Root is the first node.

You can simply check the Name of the root element :

var raw = "<Root><Node1>node1 value</Node1><Node2>node2 value</Node2></Root>";
var xml = XElement.Parse(raw);
if (xml.Name.ToString() == "Root")
    Console.WriteLine("Success");
else 
    Console.WriteLine("Fail");

score 0 · Answer 3 · answered Nov 17 '16 at 08:56

Try this solution

XDocument doc = XDocument.Parse(@"<Root><Node1>node1value</Node1><Node2>node2value</Node2></Root>");
        if(doc!=null)
        {
            if (doc.Root.Name.LocalName == "Root")
            {
                foreach (var i in doc.Descendants())
                   Console.WriteLine(i.Value);
            }
        }

How to check if first XML node exist?

3 Answers3