asked on

Read XML with Linq (the second)

I try to read the following XML Structure with Linq (yes, newbie here :) )

<registry>
<exclude_pcs>
<pc></pc>
</exclude_pcs>
<detail></detail>
<keys>
<key>HKLM\Software\Microsoft\Windows\CurrentVersion\Run</key>
<key>HKLM\Software</key>
</keys>
</registry>

My Code returns both values, but in one single string (HKLM\Software\Microsoft\Windows\CurrentVersion\Run\HKLM\Software)

What am I doing wrong?

This is what I am doing at the moment:
 
List<Object> keysSet = new List<Object>;
 
XElement configXML = XElement.Load(xmlFileName);
 
           var reg = configXML.Elements("registry");
 
            // Go through nodes
            foreach (XElement regNodes in reg)
            {
 
                // Keys
                var q = from c in regNodes.Descendants("keys")
                        select c;
 
                if (q.Count() > 0)
                {
                    foreach (String key in q)
                    {
                        if (! string.IsNullOrEmpty(key))
                        {
                            keysSet.Add(key);
                        }
                    }
                }
}

Open in new window

abel

You are looping through the keys, not through the keys/key collection. Try:

var q = from c in regNodes.Descendants("key") select c;

instead.

abel

btw, your code does not compile, the first line misses parentheses ()

Dirk Haest

You just need to change your linq-query

// Keys
var q = from c in regNodes.Descendants("key")
select c;

schubduese

ASKER

I know the code is not compiling, it's just an extract of the code... :)

thanks again abel

abel

Btw, since you placed this question on the LINQ Zone, what about making your code a bit easier by using LINQ? See snippet (tested and works with your source XML):

var reg = configXML.Elements("registry");
 
// Go through nodes
foreach (string keyValues in 
    from key in configXML.DescendantsAndSelf() 
    where key.Name == "key" 
    select key.Value)
{
 
    keysSet.Add(keyValues);
}

Open in new window

ASKER CERTIFIED SOLUTION

abel

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

Fernando Soto

Hi schubduese;

This code will get all the key values from the key node and place them into the List.

Fernando

// The list returned from query is of type string
List<String> keysSet = new List<String>();
// Load the XML document into a XElement structure
XElement configXML = XElement.Load(xmlFileName);
 
// Query the XML document for all the key nodes within the parent node keys
// and do not select those nodes with a inner text value of empty string and
// place the selected values into the List<String> keySet
keysSet = (from k in configXML.Descendants("keys").Descendants("key")
           where k.Value != String.Empty
           select k.Value).ToList();
 
// Display the values in the keySet
foreach (string key in keysSet)
{
    Console.WriteLine("Key = " + key);
}

Open in new window

schubduese

ASKER

great! thanks abel, that's fantastic!

abel

As fernando has showed, if you have <key></key> in your data that you do not want to include, you can add the "where key.Value != String.Empty" to the command:

keysSet.AddRange(from key in configXML.DescendantsAndSelf()
                 where key.Name == "key" and key.Value != String.Empty
                 select (object) key.Value);

Open in new window

Fernando Soto

Hi schubduese;

Please note that the solution by abel will select all nodes that have the name key no matter where it is in the document even if it is a child of a different node and not a child of the node keys.

Fernando

abel

That is entirely correct. But I took the liberty to take the input XML. Using the Descendants("keys").Descendants("key") you will make sure that they are a descendant to keys. Still, that doesn't help if you XML looks like this:

because then both the special keys and the normal keys will get selected. If you need a better selection from your XML if the <key> can also appear on different levels and you do not want to include those, show a bit of the XML and we will help you further with it.