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Is there a simple method of parsing XML files in C#? If so, what?

It's very simple. I know these are standard methods, but you can create your own library to deal with that much better.
Here are some examples:
XmlDocument xmlDoc= new XmlDocument(); // Create an XML document object
xmlDoc.Load("yourXMLFile.xml"); // Load the XML document from the specified file
// Get elements
XmlNodeList girlAddress = xmlDoc.GetElementsByTagName("gAddress");
XmlNodeList girlAge = xmlDoc.GetElementsByTagName("gAge");
XmlNodeList girlCellPhoneNumber = xmlDoc.GetElementsByTagName("gPhone");
// Display the results
Console.WriteLine("Address: " + girlAddress[0].InnerText);
Console.WriteLine("Age: " + girlAge[0].InnerText);
Console.WriteLine("Phone Number: " + girlCellPhoneNumber[0].InnerText);
Also, there are some other methods to work with. For example, here. And I think there is no one best method to do this; you always need to choose it by yourself, what is most suitable for you.

I'd use LINQ to XML if you're in .NET 3.5 or higher.

Use a good XSD Schema to create a set of classes with xsd.exe and use an XmlSerializer to create a object tree out of your XML and vice versa. If you have few restrictions on your model, you could even try to create a direct mapping between you model classes and the XML with the Xml*Attributes.
There is an introductory article about XML Serialisation on MSDN.
Performance tip: Constructing an XmlSerializer is expensive. Keep a reference to your XmlSerializer instance if you intend to parse/write multiple XML files.

If you're processing a large amount of data (many megabytes) then you want to be using XmlReader to stream parse the XML.
Anything else (XPathNavigator, XElement, XmlDocument and even XmlSerializer if you keep the full generated object graph) will result in high memory usage and also a very slow load time.
Of course, if you need all the data in memory anyway, then you may not have much choice.

Use XmlTextReader, XmlReader, XmlNodeReader and the System.Xml.XPath namespace. And (XPathNavigator, XPathDocument, XPathExpression, XPathnodeIterator).
Usually XPath makes reading XML easier, which is what you might be looking for.

I have just recently been required to work on an application which involved the parsing of an XML document and I agree with Jon Galloway that the LINQ to XML based approach is, in my opinion, the best. I did however have to dig a little to find usable examples, so without further ado, here are a few!
Any comments welcome as this code works but may not be perfect and I would like to learn more about parsing XML for this project!
public void ParseXML(string filePath)
{
// create document instance using XML file path
XDocument doc = XDocument.Load(filePath);
// get the namespace to that within of the XML (xmlns="...")
XElement root = doc.Root;
XNamespace ns = root.GetDefaultNamespace();
// obtain a list of elements with specific tag
IEnumerable<XElement> elements = from c in doc.Descendants(ns + "exampleTagName") select c;
// obtain a single element with specific tag (first instance), useful if only expecting one instance of the tag in the target doc
XElement element = (from c in doc.Descendants(ns + "exampleTagName" select c).First();
// obtain an element from within an element, same as from doc
XElement embeddedElement = (from c in element.Descendants(ns + "exampleEmbeddedTagName" select c).First();
// obtain an attribute from an element
XAttribute attribute = element.Attribute("exampleAttributeName");
}
With these functions I was able to parse any element and any attribute from an XML file no problem at all!

In Addition you can use XPath selector in the following way (easy way to select specific nodes):
XmlDocument doc = new XmlDocument();
doc.Load("test.xml");
var found = doc.DocumentElement.SelectNodes("//book[#title='Barry Poter']"); // select all Book elements in whole dom, with attribute title with value 'Barry Poter'
// Retrieve your data here or change XML here:
foreach (XmlNode book in nodeList)
{
book.InnerText="The story began as it was...";
}
Console.WriteLine("Display XML:");
doc.Save(Console.Out);
the documentation

If you're using .NET 2.0, try XmlReader and its subclasses XmlTextReader, and XmlValidatingReader. They provide a fast, lightweight (memory usage, etc.), forward-only way to parse an XML file.
If you need XPath capabilities, try the XPathNavigator. If you need the entire document in memory try XmlDocument.

I'm not sure whether "best practice for parsing XML" exists. There are numerous technologies suited for different situations. Which way to use depends on the concrete scenario.
You can go with LINQ to XML, XmlReader, XPathNavigator or even regular expressions. If you elaborate your needs, I can try to give some suggestions.

You can parse the XML using this library System.Xml.Linq. Below is the sample code I used to parse a XML file
public CatSubCatList GenerateCategoryListFromProductFeedXML()
{
string path = System.Web.HttpContext.Current.Server.MapPath(_xmlFilePath);
XDocument xDoc = XDocument.Load(path);
XElement xElement = XElement.Parse(xDoc.ToString());
List<Category> lstCategory = xElement.Elements("Product").Select(d => new Category
{
Code = Convert.ToString(d.Element("CategoryCode").Value),
CategoryPath = d.Element("CategoryPath").Value,
Name = GetCateOrSubCategory(d.Element("CategoryPath").Value, 0), // Category
SubCategoryName = GetCateOrSubCategory(d.Element("CategoryPath").Value, 1) // Sub Category
}).GroupBy(x => new { x.Code, x.SubCategoryName }).Select(x => x.First()).ToList();
CatSubCatList catSubCatList = GetFinalCategoryListFromXML(lstCategory);
return catSubCatList;
}

You can use ExtendedXmlSerializer to serialize and deserialize.
Instalation
You can install ExtendedXmlSerializer from nuget or run the following command:
Install-Package ExtendedXmlSerializer
Serialization:
ExtendedXmlSerializer serializer = new ExtendedXmlSerializer();
var obj = new Message();
var xml = serializer.Serialize(obj);
Deserialization
var obj2 = serializer.Deserialize<Message>(xml);
Standard XML Serializer in .NET is very limited.
Does not support serialization of class with circular reference or class with interface property,
Does not support Dictionaries,
There is no mechanism for reading the old version of XML,
If you want create custom serializer, your class must inherit from IXmlSerializable. This means that your class will not be a POCO class,
Does not support IoC.
ExtendedXmlSerializer can do this and much more.
ExtendedXmlSerializer support .NET 4.5 or higher and .NET Core. You can integrate it with WebApi and AspCore.

You can use XmlDocument and for manipulating or retrieve data from attributes you can Linq to XML classes.

Read Particular XML Node (values, not just InnerText) AND put the values in TextBox

I have been struggling for a week now and because I can not resolve this issue on my own I ask for your assistance.
I am making a C# WinForm project and am to the point where I have to read a specific part of an xml node ( mostly with 2 properties ) and have to put the 2 properties into 2 different textboxes. I have tried with the standard XML commands and the LINQ to XML commands both don't work. I will paste the part of the xml with the part of my code. Thank you all for the assistance and guidance.
XML:
<xsd xmlns="https://www.imsglobal.org/sites/default/files/xsd/ims_qtiasiv1p2p1.xsd">
<title title="SMALL TEST 1" ident="0">
<intro> SOME INTRO TEXT </intro>
<item title="Single_choice 1" ident="1">
C# code:
FileStream READER =
new FileStream(ShowPath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
XmlDocument Test = new XmlDocument();
Test.Load(READER);
Test.Load(ShowPath);
XmlNodeList NodeList = Test.GetElementsByTagName("xsd");
XmlNode Title = Test.SelectSingleNode("//title[#title='SMALL TEST 1']");
And also I have not managed to find how to navigate to a specific node in the xml. The XElement just returns some errors. Thank you all again for the help!

"..And also I have not managed to find how to navigate to a specific node in the xml"
The core problem here is, that your XML has default namespace :
xmlns="https://www.imsglobal.org/sites/default/files/xsd/ims_qtiasiv1p2p1.xsd"
That means all XML elements shown in the question are considered in this namespace (because descendant elements without prefix inherit ancestor's default namespace implicitly). This concept applies whether you're using XmlDocument or the more favorable LINQ-to-XML.
Now, to access elements in namespace with XPath, you need to use XmlNamespaceManager, register a prefix to reference your XML default namespace, and then use the registered prefix properly in your XPath, something like this :
var nsMgr = new XmlNamespaceManager(new NameTable());
nsMgr.AddNamespace("d", "https://www.imsglobal.org/sites/default/files/xsd/ims_qtiasiv1p2p1.xsd");
XmlNode Title = Test.SelectSingleNode("//d:title[#title='SMALL TEST 1']");

Trying to answer your second question, that is on a comment, I would say, that on the code you post ( please, next time use coding frame for that ), inside the Test element, there is, I assume, an namespace
https://www.imsglobal.org/sites/default/files/xsd/ims_qtiasiv1p2p1.xsd
So, if you ask for the "title" element of test, you would not obtain what you expect, unless you set first the namespace by using XmlNamespaceManager, and then
//NameSpaceAssociatedString:title
with SelectSingleNode
That is because, xml methods needs some way of finding identical tags between different namespaces.
For example
<xsd xmlns="namespace1">
<title title="SMALL TEST 1" ident="0">
</xsd>
<xsd xmlns="namespace2">
<title title="SMALL TEST 1" ident="0">
</xsd>
PD:
The code you put on comments, it works for me under .net 4.5 c# console app. No idea why it would not work for you.
Hope it helps,
Jose
Moralzarzal - Madrid
Spain

How to deal with namespaces in XML in XmlDocument c#

I have several XML documents, all of which have the same structure (element names, attribute names and hierarchy).
However, some of the elements and attribute have custom namespaces in each XML document which are not known at design time. They change, don't ask...
How can I deal with this when traversing the documents using a single set of XPath?
Should I remove all the namespaces before processing?
Can I automatically register all namespaces with an XmlNamespaceManager?
Any thoughts?
Update: some examples (with namespace declarations omitted for clarity):
<root>
<child attr="val" />
</root>
<root>
<x:child attr="val" />
</root>
<root>
<y:child z:attr="val" />
</root>
Thanks

Suppose you have following xml:
<root xmlns="first">
<el1 xmlns="second">
<el2 xmlns="third">...
You can write you queries to ignore namespaces in the following way:
/*[local-name()='root']/*[local-name()='el1']/*[local-name()='el2']
etc.
Of course you can iterate over the whole document to get namespaces and load them into nsmanager. But in general case this will cause you to evaluate every node in the document. In this case it will be faster to just treat document as a tree of objects and don't use XPath.

I believe you'll find some good insight in this Stackoverflow thread
XPath + Namespace Driving me crazy
In my opinion you have either of two solutions:
1- If the set of all possible namespaces are know before hand, then you can register them all in a XmlNamespaceManager before you begin parsing
2- Use Xpath namespace-agnostic selectors
Of course you can always scrub the xml document from any inline namespaces and start your parsing on a clean unfiorm xml without namespace.. but honestly I don't see the gain in adding this overhead step.

Scott Hanselman has a nice article about extracting all of the XML Namespaces in an XML document. Presumably, when you get all of the XML Namespaces, you can just iterate over all of them and register them in your namespace manager.

You could try something like this to strip the namespaces:
//Implemented based on interface, not part of algorithm
public string RemoveAllNamespaces(string xmlDocument)
{
return RemoveAllNamespaces(XElement.Parse(xmlDocument)).ToString();
}
//Core recursion function
private XElement RemoveAllNamespaces(XElement xmlDocument)
{
if (!xmlDocument.HasElements)
{
XElement xElement = new XElement(xmlDocument.Name.LocalName);
xElement.Value = xmlDocument.Value;
return xElement;
}
return new XElement(xmlDocument.Name.LocalName, xmlDocument.Elements().Select(el => RemoveAllNamespaces(el)));
}
See Peter Stegnar's answer here for more details:
How to remove all namespaces from XML with C#?

You can also use direct node tests with wildcards, which will match any namespace (or lack thereof):
$your-document/*:root/*:child/#*:attr

Querying XML Without Worrying about Namespaces

I have XML with and without a prefix on elements, but no namespaces defined for any of them. When I try to load this, it gives me an error on XDocument.Load (at least, I think that's where it happens) that certain prefixes are not defined. Is there a way to tell the framework to ignore any namespace prefixes? I'm using LINQ to XML, but could use something else if available.
I can't necessarily pre-define them because I'm going to be working with a variety of documents that may or may not have a prefix defined and no definitive xmlns declaration.

Aren't prefixes supposed to represent an abbreviation for a namespace? I believe you need to clean up those prefixes that have no namespace associated with them in the first place before processing it, since it isn't valid XML. A quick regex to replace all prefixes of the form </prefix: with </: and <prefix: with < should do it.
To do this, first replace the following regex matches
</.*?: with </
and <.*?: with < (do not change the ordering).

An approach to what you want to do may be using XmlDocument:
XmlDocument d = new XmlDocument();
using (var textReader = new XmlTextReader(#"test.xml"))
{
textReader.Namespaces = false;
d.Load(textReader);
}
You will lose the power of querying the data using the syntax of LINQ to XML.
You can actually use LINQ to XML and ignore the namespace by setting for each prefix in the file the folowing line
nameSpaceManager.AddNamespace("prefixName", "urn:ignore");
where nameSpaceManager is of type XmlNamespaceManager.
But from your question i sense that this is not a reasonable solution.

Parse XML in C#

Hello I want to know how can I parse this simple XML file content in C#. I can have multiple "in" elements, and from those I want to use date, min, max and state child values.
<out>
<in>
<id>16769</id>
<date>29-10-2010</date>
<now>12</now>
<min>12</min>
<max>23</max>
<state>2</state>
<description>enter text</description>
</in>
<in>
<id>7655</id>
<date>12-10-2010</date>
<now>1</now>
<min>1</min>
<max>2</max>
<state>0</state>
<description>enter text</description>
</in>
</out>

The System.XML namespace has all sorts of tools for parsing, reading, and writing XML data. By the way, your XML isn't well-formed; you've got two <out> elements, but only one </out> element.

Linq to xml is also helpful for parsing xml -
http://msdn.microsoft.com/en-us/library/bb387098.aspx
Also -
http://msdn.microsoft.com/library/bb308960.aspx

You need System.XML, starting with XmlDocument.Load(filename).
Once you have the XmlDocument loaded, you can drill down into it as needed using the built-in .Net XML object model, starting from XmlDocument level. You can walk the tree recursively in a pretty intuitive way, capturing what you want from each XmlNode as you go.
Alternatively (and preferably) you can quickly locate all XmlNodes in your XmlDocument that match certain conditions using XPath - examples here. An example of usage in C# is XmlNode.SelectNodes.
using System;
using System.IO;
using System.Xml;
public class Sample {
public static void Main() {
XmlDocument doc = new XmlDocument();
doc.Load("booksort.xml");
XmlNodeList nodeList;
XmlNode root = doc.DocumentElement;
nodeList=root.SelectNodes("descendant::book[author/last-name='Austen']");
//Change the price on the books.
foreach (XmlNode book in nodeList)
{
book.LastChild.InnerText="15.95";
}
Console.WriteLine("Display the modified XML document....");
doc.Save(Console.Out);
}
}

Examples can be found here http://www.c-sharpcorner.com/uploadfile/mahesh/readwritexmltutmellli2111282005041517am/readwritexmltutmellli21.aspx

This might be beyond what you want to do, but worth mentioning...
I hate parsing XML. Seriously, I almost refuse to do it, especially since .NET can do it for me. What I would do is create an "In" object that has the properties above. You probably have one already, or it would take 60 seconds to create. You'll also need a List of In objects called "Out".
Then just deserialze the XML into the objects. This takes just a few lines of code. Here is an example. BTW, this makes changing and re-saving the data just as easy.
How to serialize/deserialize