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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.
I'm trying to capture the attribute "description" in this XML:
<ProductoModel xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/WebApi.Models">
<descripcion>descripcion 1</descripcion>
<fecha_registro>2016-03-01</fecha_registro>
<id_producto>1</id_producto>
<id_proveedor>1</id_proveedor>
<nombre_producto>producto 1</nombre_producto>
<precio>200</precio>
</ProductoModel>
My Code :
XmlDocument xDoc = new XmlDocument();
xDoc.LoadXml(content);
XmlNamespaceManager manager = new XmlNamespaceManager(xDoc.NameTable);
manager.AddNamespace("MYNS", "http://schemas.datacontract.org/2004/07/WebApi.Models");
XmlNode node = xDoc.DocumentElement.SelectSingleNode("MYNS:ProductoModel", manager);
MessageBox.Show(node.Attributes.GetNamedItem("descripcion").Value);
The problem is I can not capture the attribute "descripcion" and get the following error:
Object reference not set to an instance of an object.
As I can capture the required attribute?
<descripcion> is not attribute. It is element.
You can get any element (or attribute) with a single xpath query.
XmlNode node = xDoc.DocumentElement.SelectSingleNode("/MYNS:ProductoModel/MYNS:descripcion", manager);
MessageBox.Show(node.InnerText);
Note the character / at the beginning of the xpath expression.
If you want another easy way operate XML, check this out. This is a little tool for xml operate, it's much easier to use and understand than XmlNode.
I am using c# console app to get xml document. Now once xmldocument is loaded i want to search for specific href tag:
href="/abc/def
inside the xml document.
once that node is found i want to strip tag completly and just show Hello.
Hello
I think i can simply get the tag using regex. But can anyone please tell me how can i remove the href tag completly using regex?
xml & html same difference: tagged content. xml is stricter in it's formatting.
for this use case I would use transformations and xpath queries rebuild the document. As #Yahia stated, regex on tagged documents is typically a bad idea. the regex for parsing is far to complex to be affective as a generic solution.
The most popular technology for similar tasks is called XPath. (It is also a key component of XQuery and XSLT.) Would the following perhaps solve your task, too?
root.SelectSingleNode("//a[#href='/abc/def']").InnerText = "Hello";
You could try
string x = #"<?xml version='1.0'?>
<EXAMPLE>
<a href='/abc/def'>Hello</a>
</EXAMPLE>";
System.Xml.XmlDocument doc = new XmlDocument();
doc.LoadXml(x);
XmlNode n = doc.SelectSingleNode("//a[#href='/abc/def']");
XmlNode p = n.ParentNode;
p.RemoveChild(n);
System.Xml.XmlNode newNode = doc.CreateNode("element", "a", "");
newNode.InnerXml = "Hello";
p.AppendChild(newNode);
Not really sure if this is what you are trying to do but it should be enough to get you headed in right direction.
I am parsing an XML document in C# ASP.NET. Is there a way/function that I don't know of to get all the elements of the tag "course"?
The format of the XML is like so:
<a>
<g1>
<course></course>
<g9>
<course></course>
... more course elements
</g9>
<course></course>
<g2>
<g3>
<course></course>
...
</g3>
</g2>
</g1>
</a>
When I do the following code I get back no "course" elements, is there a simple function that can grab all these elements in one go?
XmlDocument xdoc = new XmlDocument();
xdoc.Load("http://kjkjkj.com");
XmlNodeList list = xdoc.DocumentElement.SelectNodes("course");
// if I debug: list.count = 0 but if I look at xdoc.DocumentElement.outerXml
// its the correct XML so I did parse the file & get XML contents.
// Is there any C# equivalent of document.getElementsByTagName("course"); ???
You were close:
XmlNodeList list = xdoc.DocumentElement.SelectNodes("//course");
Prefixing with // will grab all the nodes in the document named course, no matter where they are.
As an alternative you should consider parsing your XML with Linq to Xml which integrates nicely with Linq to objects. The equivalent syntax for the same there is
var courses = xdoc.Descendants("course");
i have a scenario where i need to check for the node count in a XML file. Since the XPath may vary for different scenarios, i would like to configure this in a xml / text file
I checked at XQuery but I hardly find any implementation in C#.
Since LINQ also does the similar thing, i am thinking of using it.
Ex. XML:
<ROOT><NODE1><TXT>ABC</TXT></NODE1><NODE1><TXT>DEF</TXT></NODE1></ROOT>
I would like to configure my condition like this (in a text file):
/ROOT/NODE1/TXT [COUNT=2]
there will n-number of xpath like this
How easily can I use LINQ, Check for XPATH and get the count?
Thanks in advance
Cheers,
Karthik
Check the reference System.Xml.Xpath which allows you to use xpath to work with Xml data.
XDocument doc = XDocument.Load(filePath);
var xPath = #"/ROOT/NODE1/TXT";
int count = doc.XPathSelectElements(xPath).Count();
XDocument doc = XDocument.Load(xmlFilePath);
int count = doc.Descendants("TXT").Count();
In this case you can do:
XDocument doc = XDocument.Load(filePath);
var xPath = #"/ROOT/NODE1/TXT";
int count = doc.Descendants(xPath.Substring(xPath.LastIndexOf("//") + 1)).Count();
but it's not general case, whould you explain more details about your condition to force using XPath strings?