Develop Reference

How to Get XML Element by It's 'Value' using XML C# SDK

I have this snippt of XML
<unit class="xxx.xxx.xxx" id="382">
<customId>000</customId>
<description>kg</description>
<key>22452</key>
<Description>Kilogramm</Description>
</unit>
how to get the node 'unit' or parnet of the key element using the value of an element. For instance
i have the value of key element above [22452] and it's Uniqe inside the xml-File.
what i am trying to do getting value of customid [000] of that specific tag.
what i did:
var doc = new XmlDocument();
doc.Load(stream); // stream from xml-file
var key = doc.SelectSingleNode(//key/[text()='" + 22452+ "']"); // that i am not sure about it.
var customId = key.InnerText("customId");

For this kind of query you could either find the node and than navigate to the parent.
Or use XPath:
var unitElemnt = doc.SelectSingleNode("//unit[key = '22452']");
(Assuming I've remembered the XPath to match an element's text content correctly.)
This gets a reference to the <unit> element, by using a relative path to the <key> element in the predicate of the XPath expression.
Generally better to avoid // in XPath for performance, but would need full document structure to do that.

For this you can use Linq to Xml queries.
XElement units = XElement.Load("./Test.xml");
XElement unit = (from item in units.Descendants("unit")
where item.Element("key").Value == "22455"
select item).FirstOrDefault();
string customId = unit.Element("customId").Value;
supposing your xml file look like :
<?xml version="1.0" encoding="utf-8"?>
<units>
<unit class="xxx.xxx.xxx" id="385">
<customId>003</customId>
<description>kg</description>
<key>22455</key>
<Description>Kilogramm</Description>
</unit>
<unit class="xxx.xxx.xxx" id="386">
<customId>004</customId>
<description>kg</description>
<key>22456</key>
<Description>Kilogramm</Description>
</unit>
</units>
for more reading check Microsoft Linq to Xml Docs

Select an XML node with a given child value and update a different child element

I have the following xml file:
<LabelImageCreator xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<PrintFieldList>
<PrintFieldDefinition>
<FieldName>Facility</FieldName>
<DataParameterName>Address</DataParameterName>
<FieldFont>
<FontName>Arial</FontName>
<FontSize>10</FontSize>
<FontStyle>Regular</FontStyle>
</FieldFont>
<CurrentDataValue/>
</PrintFieldDefinition>
<PrintFieldDefinition>
<FieldName>Country</FieldName>
<DataParameterName>CountryofOrigin</DataParameterName>
<WrapField>false</WrapField>
<FieldFont>
<FontName>Arial</FontName>
<FontSize>8</FontSize>
<FontStyle>Regular</FontStyle>
</FieldFont>
<CurrentDataValue/>
<TextPrefix>Produce of </TextPrefix>
</PrintFieldDefinition>
<PrintFieldList>
<LabelImageCreator>
I have to select the attribute with field name Facilityand add the address(eg: No 2546, Gorrge street, California, US) to <CurrentDataValue/> field and save it.
I tried with the below code,
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(path);
var node = xmlDocument.DocumentElement.SelectSingleNode(
"./PrintFieldList/PrintFieldDefinition[#FieldName='Facility']");
Above code while debuging it is not working. Can any one guide me how to select and update the xml attribute.

A couple of minor issues:
You need to start from the root element LabelImageCreator
FieldName is an element, not an attribute, so hence FieldName and not #FieldName
The closing tags on the Xml Document don't match up.
If you want to select the child element CurrentDataValue of parent PrintFieldDefinition with the child FieldName with value Facility:
var node = xmlDocument.DocumentElement.SelectSingleNode(
"/LabelImageCreator/PrintFieldList/PrintFieldDefinition[FieldName='Facility']/CurrentDataValue");
Changing the value is then simply:
node.InnerText = "No 2546, Gorrge street, California, US";

I would use XDocument instead of XmlDocument (it allows you to use linq which in my opinion, is easier than using xpath).
You can find your node like this and I believe you can update them too (first search and get the value, then search again and update on the other node).
Example:
var nodesMatching = from node in myXDocument.Descendants()
where node.Name.LocalName.Equals("mySearchNode")
select node;
var node = nodesMatching.FirstOrDefault();

How to check XMLNode is exist or not in Windows Phone

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?

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

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!

Unable to remove root node from an xml document using linq to xml c#

Actullay, I need to get all elements except root node from first xml document and so that I could insert them as child nodes to an element(that has same name as a previous doc's root name) in a new document.
So I have tried various ways to achieve it, one of them is removing the root node of first and then trying to add elements to a new one's as given below:
I have tried the following but could not achieve it.
XDocument testDoc = XDocument.Parse(Mydocument);
testDoc.Descendants().Where(e => e.Name.LocalName == "rootName").Select(m=>m).Single().Remove();
var resultDoc = testDoc;
The above code is giving me an empty "{}" result.
my xml document looks something like the below one's:
<rootName xsi:schemaLocation="" xmlns:xsi="" xmlns="">
<main>
<child>
</child>
<anotherchild>
</anotherchild>
</main>
</rootName>
And another way is getting all the elements of first document as the following:
var resultDoc = testDoc.Descendants(ns + "rootName").Elements();
the above statement is giving me the list of elements in the "testDoc" which
I need to do something like below, I am clueless:
<AnotherDocument xsi:schemaLocation="" xmlns:xsi="" xmlns="">
<firstNode>
<rootName>
<main>
<child>
</child>
<anotherchild>
</anotherchild>
</main>
</rootName>
</firstNode>
Please let me know how to insert those elements in a new document as above if I am correct else let me know the way to resolve this issue.
Thanks in advance.

You can replace content of rootName element in another document with elements from first document root:
var xDoc = XDocument.Parse(Mydocument);
var anotherXDoc = XDocument.Load("anotherdata.xml");
XNamespace ns = "http://..."; // your xml namespance
var rootName = anotherXDoc.Descendants(ns + "rootName").First();
rootName.ReplaceNodes(xDoc.Root.Elements());

By this page_nodes gets all nodes now you can used all node by for each loop
var page_nodes = from p in xdoc.Descendants.Where(e => e.Name.LocalName == "rootName").Select(m=>m).Single().Remove() select p;
foreach (var page_node in page_nodes)
{
//Do stuff
}

Wouldn't removing a root node, remove all its child nodes as well? The result you are getting is to be expected I think. You should probably get all the children of the root and copy them to your new document.

Get specific values from Xml

I don't how to extract the values from XML document, and am looking for some help as I'm new to C#
I am using XmlDocument and then XmlNodeList for fetching the particular XML document
Here is my code
XmlNodeList XMLList = doc.SelectNodes("/response/result/doc");
And my XML looks like this:
<?xml version="1.0" encoding="UTF-8"?>
<response>
<result>
<doc>
<long name="LoadID">494</long>
<long name="EventID">5557</long>
<str name="XMLData"><TransactionDate>2014-05-28T14:17:31.2186777-06:00</TransactionDate><SubType>tblQM2222Components</SubType><IntegerValue title="ComponentID">11111</IntegerValue></str></doc>
<doc>
<long name="LoadID">774</long>
<long name="EventID">5558</long>
<str name="XMLData"><TransactionDate>2014-05-28T14:17:31.2186777-06:00</TransactionDate><SubType>tblQM2222Components</SubType><IntegerValue title="ComponentID">11111</IntegerValue></str></doc>
</result>
</response>
In this i have to fetch every the XMLData data that is under every doc tag and i have to fetch last doc tag EventID.

var xml = XDocument.Parse(xmlString);
var docs = xml.Root.Elements("doc");
var lastDocEventID = docs.Last()
.Elements("long")
.First(l => (string)l.Attribute("name") == "EventID")
.Value;
Console.WriteLine ("Last doc EventId: " +lastDocEventID);
foreach (var doc in docs)
{
Console.WriteLine (doc.Element("str").Element("TransactionDate").Value);
}
prints:
Last doc EventId: 5558
2014-05-28T14:17:31.2186777-06:00
2014-05-28T14:17:31.2186777-06:00

You can use two XPath expressions to select the nodes you want. To answer each part of your question in turn:
To select all of the XMLData nodes:
XmlNodeList XMLList
= doc.SelectNodes("/response/result/doc/str[#name='XMLData']");
To select the last EventId:
XmlNode lastEventIdNode =
doc.SelectSingleNode("/response/result/doc[position() =
last()]/long[#name='EventID']");
If not all doc nodes are guaranteed to have an event id child node, then you can simply:
XmlNodeList eventIdNodes =
doc.SelectNodes("/response/result/doc[long[#name='EventID']]");
XmlNode lastNode = eventIdNodes[eventIdNodes.Count - 1];
That should give you what you've asked for.
Update;
If you want the XML data inside each strXml element, you can use the InnerXml property:
XmlNodeList xmlList
= doc.SelectNodes("/response/result/doc/str[#name='XMLData']");
foreach(XmlNode xmlStrNode in xmlList)
{
string xmlInner = xmlStrNode.InnerXml;
}

There's one result tag short in your xml.
Try using this. It's cleaner too imho
XmlNodeList docs = doc.SelectSingleNode("response").SelectSingleNode("result").SelectNodes("doc");
Then you can use a combination of SelectSingleNode, InnerText, Value to get the data from each XmlNode in your list.
For example if you want the EventID from the first doc tag:
int eventID = int.Parse(docs[0].SelectSingleNode("long[#name='EventID']").InnerText);