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c# extract value from nextnode

I have the following xml part and am trying to extract the value where key is known. The example below is a snippet, from a larger xml that contains 1000's of nodes.
<?xml version="1.0" encoding="utf-8"?>
<DictionarySerializer>
<item>
<key>key1</key>
<value>CONTENT1</value>
</item>
<item>
<key>key2</key>
<value>CONTENT2</value>
</item>
</DictionarySerializer>
i assume the above is a string called xml,
then with
XDocument.Parse(xml)
.Descendants("key")
.Where(x => (string)x.Value == "key1")
.FirstOrDefault().NextNode.ToString()
I can get the string <value>CONTENT1</value> But i simply cannot get my head around how to get the value of the value node to to say.
I am afrad it is super simple, and i just are stuck in a coffein loop :-)

XDocument.Parse(xml)
.Descendants("key")
.Where(x => (string)x.Value == "key1")
.FirstOrDefault().Value.ToString()
you should use .Value property instead of .NextNode

If you want to get all keys and values from the XML from all 1000 elemnts. You can use:
Dictionary<string, string> elements = new Dictionary<string, string>();
xml.Root.Elements().ToList().ForEach(xmlElement =>
{
elements.Add(xmlElement.Descendants("key").First().Value,
xmlElement.Descendants("value").First().Value);
});
So, the elements dictionary will contain all of your 1000 nodes.

Try to cast NextNode to XElement and get Value from it.

Considering you can use XPath expressions.
expression = #"//Item[Key='1']/Value"
XmlNodeList nodeList = xmlDocument.SelectNodes(expression);
This would give you the value node(s) of items with Key=1. Just find the value of the desired node.
I believe using XDocument you can also try,
string output = xDocument.XPathEvaluate(expression);

How to delete certain root from xml file?

My '.xml' file looks this way:
<?xml version="1.0" encoding="utf-8"?>
<Requestes>
<Single_Request num="1">
<numRequest>1</numRequest>
<IDWork>1</IDWork>
<NumObject>1</NumObject>
<lvlPriority>Высокий</lvlPriority>
</Single_Request>
<Single_Request num="2">
<numRequest>2</numRequest>
<IDWork>2</IDWork>
<NumObject>2</NumObject>
<lvlPriority>Средний</lvlPriority>
</Single_Request>
<Periodic_Request num="1">
<numRequest>3</numRequest>
<IDWork>23</IDWork>
<pFrequency>23</pFrequency>
<lvlPriority>Низкий</lvlPriority>
<time_service>23</time_service>
<time_last_service>23</time_last_service>
<relative_time>23</relative_time>
</Periodic_Request>
</Requestes>
So I need to delete Single_Request with atribute value equal to sTxtBlock_numRequest.Text. I have tried to do it this way:
XDocument doc = XDocument.Load(FilePath);
IEnumerable<XElement> sRequest = doc.Root.Descendants("Single_Request").Where(
t => t.Attribute("num").Value =="sTxtBlock_numRequest.Text"); //I'm sure, that problem is here
sRequest.Remove();
doc.Save(FilePath);
Unfortunattly, nothing has happanned, don`t know how to solve the problem.
This is why , I am looking forward to your help.

You are comparing attribute value with string literal "sTxtBlock_numRequest.Text". You should pass value of textbox text instead:
doc.Root.Elements("Single_Request")
.Where(t => (string)t.Attribute("num") == sTxtBlock_numRequest.Text)
.Remove();
Note - it's better to use Elements when you are getting Single_Request elements of root, because Descendants will search whole tree, instead of looking at direct children only. Also you can call Remove() without saving query to local variable.

xml Nodes by Element

Below is an example of the xml file that I need to pull data via C#. This is my first experience with reading xml files and a beginner with xml. Anyone have an example of how I would find/load the fieldorder values for Export_B?
<?xml version="1.0" encoding="utf-8"?>
<Config>
<OutFolderCSV>c:\Output\2012\upload_Files</OutFolderCSV>
<OutFolderImage>c:\Output\2012\NM_Scorecard_Images</OutFolderImage>
<PathOutLogFile>c:\Output\2012\Log\Matches.log</PathOutLogFile>
<FieldSeparator>,</FieldSeparator>
<ExportFile>
<Name>Export_A</Name>
<FieldOrder>matchID</FieldOrder>
<FieldOrder>contactID</FieldOrder>
<FieldOrder>stageID13</FieldOrder>
<FieldOrder>stringScore1a</FieldOrder>
<FieldOrder>xScore1a</FieldOrder>
<FieldOrder>stageID14</FieldOrder>
<FieldOrder>stringScore1b</FieldOrder>
<FieldOrder>xScore1b</FieldOrder>
<FieldOrder>stageID15</FieldOrder>
<FieldOrder>stringScore1c</FieldOrder>
<FieldOrder>xScore1c</FieldOrder>
</ExportFile>
<ExportFile>
<Name>Export_B</Name>
<FieldOrder>matchID</FieldOrder>
<FieldOrder>contactID</FieldOrder>
<FieldOrder>stageID16</FieldOrder>
<FieldOrder>stringScore1a</FieldOrder>
<FieldOrder>xScore1a</FieldOrder>
<FieldOrder>stageID17</FieldOrder>
<FieldOrder>stringScore1b</FieldOrder>
<FieldOrder>xScore1b</FieldOrder>
<FieldOrder>stageID18</FieldOrder>
<FieldOrder>stringScore1c</FieldOrder>
<FieldOrder>xScore</FieldOrder>
</ExportFile>
</Config>

Using LINQ to XML:
var doc = XDocument.Load(#"c:\path\to\file.xml");
var fieldOrders =
from exportFile in doc.Descendants("ExportFile")
where (string)exportFile.Element("Name") == "Export_B"
from fieldOrder in exportFile.Elements("FieldOrder")
select (string)fieldOrder;

I have written an article
http://www.codeproject.com/Articles/33769/Basics-of-LINQ-Lamda-Expressions
on XML using XDocument object.
You can parse the XML easily using
XDocument.Load(filepath)
Please read the section XLinq to parse the objects.
edit :
You can change value of Export_B using the code :
var document = XDocument.Load(filepath)
var exportFiles = document.Descandants("ExportFile");
List<XElement> list = new List<XElement>();
foreach(var element in exportFiles)
{
list.Add(element);
// Now you can do element.Element("Name") to get the name. Put a breakpoint on this, you can get the reference of all underlying objects.
}

C# - Linq to XML - Exclude elements from query

I have this XML file:
<MyXml>
<MandatoryElement1>value</MandatoryElement1>
<MandatoryElement2>value</MandatoryElement2>
<MandatoryElement3>value</MandatoryElement3>
<CustomElement1>value</CustomElement1>
<CustomElement2>value</CustomElement2>
<MyXml>
All 3 elements that are called 'MandatoryElementX' will always appear in the file. The elements called 'CustomElementX' are unknown. These can be added or removed freely by a user and have any name.
What I need is to fetch all the elements that are not MandatoryElements. So for the file above I would want this result:
<CustomElement1>value</CustomElement1>
<CustomElement2>value</CustomElement2>
I don't know what the names of the custom elements may be, only the names of the 3 MandatoryElements, so the query needs to somehow exclude these 3.
Edit:
Even though this was answered, I want to clarify the question. Here is an actual file:
<Partner>
<!--Mandatory elements-->
<Name>ALU FAT</Name>
<InterfaceName>Account Lookup</InterfaceName>
<RequestFolder>C:\Documents and Settings\user1\Desktop\Requests\ALURequests</RequestFolder>
<ResponseFolder>C:\Documents and Settings\user1\Desktop\Responses</ResponseFolder>
<ArchiveMessages>Yes</ArchiveMessages>
<ArchiveFolder>C:\Documents and Settings\user1\Desktop\Archive</ArchiveFolder>
<Priority>1</Priority>
<!--Custom elements - these can be anything-->
<Currency>EUR</Currency>
<AccountingSystem>HHGKOL</AccountingSystem>
</Partner>
The result here would be:
<Currency>EUR</Currency>
<AccountingSystem>HHGKOL</AccountingSystem>

You can define a list of mandatory names and use LINQ to XML to filter:
var mandatoryElements = new List<string>() {
"MandatoryElement1",
"MandatoryElement2",
"MandatoryElement3"
};
var result = xDoc.Root.Descendants()
.Where(x => !mandatoryElements.Contains(x.Name.LocalName));

Do you have created this xml or do you get it by another person/application?
If it's yours I would advise you not to number it. You can do something like
<MyXml>
<MandatoryElement id="1">value<\MandatoryElement>
<MandatoryElement id="2">value<\MandatoryElement>
<MandatoryElement id="3">value<\MandatoryElement>
<CustomElement id="1">value<\CustomElement>
<CustomElement id="2">value<\CustomElement>
<MyXml>
In the LINQ-Statement you don't need the List then.

Your question shows improperly formatted XML but I am assuming that is a typo and the real Xml can be loaded into the XDocument class.
Try this...
string xml = #"<MyXml>
<MandatoryElement1>value</MandatoryElement1>
<MandatoryElement2>value</MandatoryElement2>
<MandatoryElement3>value</MandatoryElement3>
<CustomElement1>value</CustomElement1>
<CustomElement2>value</CustomElement2>
</MyXml> ";
System.Xml.Linq.XDocument xDoc = XDocument.Parse(xml);
var result = xDoc.Root.Descendants()
.Where(x => !x.Name.LocalName.StartsWith("MandatoryElement"));

lets say TestXMLFile.xml will contain your xml,
XElement doc2 = XElement.Load(Server.MapPath("TestXMLFile.xml"));
List<XElement> _list = doc2.Elements().ToList();
List<XElement> _list2 = new List<XElement>();
foreach (XElement x in _list)
{
if (!x.Name.LocalName.StartsWith("Mandatory"))
{
_list2.Add(x);
}
}
foreach (XElement y in _list2)
{
_list.Remove(y);
}

XPath and attributes

I'm trying to traverse an XML document and select certain node attributes. The XML is dynamically generated.
<?xml version="1.0" encoding="ISO-8859-1"?>
<streams>
<stream>
<title>+23 (Panama)</title>
<info resolution="768x420" bitrate="1000kbps"/> ----- Need These
<swfUrl>http://www.freeetv.com/script/mediaplayer/player.swf</swfUrl>
<link>rtmp://200.75.216.156/live/</link>
<pageUrl>http://www.freeetv.com/</pageUrl>
<playpath>livestream</playpath>
<language>Music</language>
<advanced></advanced>
</stream>
</streams>
The code that I'm trying to use with zero luck and Visual Studio saying "No you're wrong. Try 600 more times" is
xDoc.Load("http://127.0.0.1/www/xml.php");
XmlNodeList nodes = xDoc.SelectNodes("/streams/stream");
foreach (XmlNode xn in nodes)
{
ListViewItem lvi = listView1.Items.Add(xn["title"].InnerText);
lvi.SubItems.Add(xn["swfUrl"].InnerText);
lvi.SubItems.Add(xn["link"].InnerText);
lvi.SubItems.Add(xn["pageUrl"].InnerText);
lvi.SubItems.Add(xn["playpath"].InnerText);
lvi.SubItems.Add(xn["language"].InnerText);
lvi.SubItems.Add(xn["advanced"].InnerText);
lvi.SubItems.Add(xn["//info/#resolution"].Value);
}
Please tell me oh wise ones what am I doing wrong?

If you want to select node's attribute using XPath you should use SelectSingleNode method, e.g.:
xn.SelectSingleNode("info/#resolution").Value

To select resolution attribute of your last node you need to use:
xn["info"].Attributes["resolution"].Value
Alternatively, you can try LINQ to XML for the same results (I find its API easier to use):
var doc = XDocument.Parse("http://127.0.0.1/www/xml.php");
foreach (var d in doc.Descendants("stream"))
{
ListViewItem lvi = listView1.Items.Add(d.Element("title").Value);
lvi.SubItems.Add(d.Element("swfUrl").Value);
// ...
vi.SubItems.Add(d.Element("info").Attribute("resolution").Value);
}

Here is an example of LINQ to XML to extract attributes from the entire document of a particular attribute name OR list of attribute names.
var xml = XElement.Parse("http://127.0.0.1/www/xml.php");
// find all attributes of a given name
var attributes = xml
.Descendants()
.Attributes("AttributeName")
// find all attributes of multiple names
var attributes = xml
.Descendants()
.Attributes()
.Where(a => ListOfAttribNames.Contains(a.Name.LocalName))

Replace:
lvi.SubItems.Add(xn["//info/#resolution"].Value);
with:
lvi.SubItems.Add(xn.SelectSingleNode("info/#resolution").Value);