How to check XMLNode is exist or not in Windows Phone

Question

I am writing Windows Phone 8 application, and I am getting XML data from web service,in some response, in my XML document I am getting some "Tags" and in other response I do not getting those tags, so how do I check that XNode is exist or not? See my XML document below:

<?xml version="1.0" encoding="UTF-8"?>
<root>
   <Group>
     <Id>205647</Id>
     <Name>Docs</Name>
   </Group>

   <Group>
    <Id>205648</Id>
    <Name>Photos</Name>
   </Group>
</root>

Now, in above document, the Descendant "GROUP" is exist in some results and doesn't exist in other results,How do I check that?

score 1 · Answer 1 · answered Jun 25 '14 at 05:51

1

Create an extension method like this :

public static string TryGetElementValue(this XElement parentEl, string elementName, string defaultValue = null) 
{
    var foundEl = parentEl.Element(elementName);
    if(foundEl != null)
    {
         return foundEl.Value;
    }
    else
    {
         return defaultValue;
    }
}

This approach allows you to keep a clean code with isolating the check of element presence. It also allow you to define a default value, which can be helpful

answered Jun 25 '14 at 05:51

Amit Bhatiya

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user3683136, thanx man, how do I call it, in calling there are some problems!!thank you very much!! – Nitesh Kothari Jun 25 '14 at 05:55
like this: id = Group.TryGetElementValue("Id") – Amit Bhatiya Jun 25 '14 at 05:58

score 1 · Answer 2 · edited May 23 '17 at 12:05

1

You could go through all nodes with the XmlTextReader and look for a specific XmlNode Name.

http://www.w3schools.com/xpath/xpath_syntax.asp

Try this snippet with your xml:

 XmlDocument doc = new XmlDocument();
  doc.Load("your.xml");

  //Select the book node with the matching attribute value.
  XmlNode nodeToFind;
  XmlElement root = doc.DocumentElement;

  // Selects all the title elements that have an attribute named group
  nodeToFind = root.SelectSingleNode("//title[@group]");

  if( nodeToFind != null )
  {
       // It was found, manipulate it.
  }
  else
 {
       // It was not found.
  }

Have a look at this too. updating an existing xml file in Windows Phone

Hope it helps!

edited May 23 '17 at 12:05

Community

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1

answered Jun 25 '14 at 05:53

Kulasangar

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5
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anonshankar, I am not getting XmlElement and XmlNode in my code behind file, how to over-come this??Thank you!! – Nitesh Kothari Jun 25 '14 at 06:33
@NiteshKothari did you add the namespace? using System.Xml – Kulasangar Jun 25 '14 at 06:38
anonshankar, yes man,I have added it!!XDocument doc = XDocument.Parse(e.Result); I am getting XElement and XNode.Thank you!! – Nitesh Kothari Jun 25 '14 at 06:43
anonshankar, No,I have not executed, because I am not getting those XmlNode and XElement.Once code will done,then I check!!Thank you!! – Nitesh Kothari Jun 25 '14 at 06:48
yep that would be better. But as far as I know if you've got the namespace you should be able to access the XML properties. Aren't you getting any kind of squiggly under the code? – Kulasangar Jun 25 '14 at 06:50
what does it say when you hover over? – Kulasangar Jun 25 '14 at 06:53
1

The type or naamespace 'XmlNode' couldn't be found!! – Nitesh Kothari Jun 25 '14 at 06:54
That means you're missing this namespace. Recheck whether you're having it http://msdn.microsoft.com/en-us/library/system.xml.aspx Using System.Xml – Kulasangar Jun 25 '14 at 07:02

How to check XMLNode is exist or not in Windows Phone

2 Answers2