How do I read and parse an XML file in C

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LINQ to XML Example      Loading from a file  you can also load from a stream var xml   XDocument Load   C  contacts xml         Query the data and write out a subset of contacts var query   from c in xml Root Descendants  contact               where  int c Attribute  id    lt  4             select c Element  firstName   Value                            c Element  lastName   Value    foreach  string name in query        Console WriteLine  Contact s Full Name   0    name       Reference  LINQ to XML at MSDN

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Linq to XML   Also  VB NET has much better xml parsing support via the compiler than C    If you have the option and the desire  check it out

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Check out XmlTextReader class for instance

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Here s an application I wrote for reading xml sitemaps   using System  using System Collections Generic  using System Windows Forms   using System Linq  using System Text  using System Threading Tasks  using System IO  using System Data  using System Xml   namespace SiteMapReader       class Program               static void Main string   args                        Console WriteLine  Please Enter the Location of the file                    get the location we want to get the sitemaps from              string dirLoc   Console ReadLine                    get all the sitemaps              string   sitemaps   Directory GetFiles dirLoc               StreamWriter sw   new StreamWriter Application StartupPath      locs txt   true                   loop through each file              foreach  string sitemap in sitemaps                                try                                          new xdoc instance                      XmlDocument xDoc   new XmlDocument                           load up the xml from the location                      xDoc Load sitemap                           cycle through each child noed                      foreach  XmlNode node in xDoc DocumentElement ChildNodes                                                   first node is the url     have to go to nexted loc node                          foreach  XmlNode locNode in node                                                           thereare a couple child nodes here so only take data from node named loc                              if  locNode Name     loc                                                                    get the content of the loc node                                  string loc   locNode InnerText                                      write it to the console so you can see its working                                  Console WriteLine loc   Environment NewLine                                       write it to the file                                  sw Write loc   Environment NewLine                                                                                                                   catch                               Console WriteLine  All Done  -                  Console ReadLine                        static void readSitemap                                 Code on Paste Bin  http   pastebin com yK7cSNeY

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public void ReadXmlFile                 string path   HttpContext Current Server MapPath    App Data       Finds the location of App Data on server          XmlTextReader reader   new XmlTextReader System IO Path Combine path   XMLFile7 xml       Combines the location of App Data and the file name         while  reader Read                          switch  reader NodeType                                case XmlNodeType Element                      break                  case XmlNodeType Text                      columnNames Add reader Value                       break                  case XmlNodeType EndElement                      break                                  You can avoid the first statement and just specify the path name in constructor of XmlTextReader

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You could use a DataSet to read XML strings   var xmlString   File ReadAllText FILE PATH   var stringReader   new StringReader xmlString   var dsSet   new DataSet    dsSet ReadXml stringReader     Posting this for the sake of information

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You can either    Use XmlSerializer class Use XmlDocument class   Examples are on the msdn pages provided

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There are lots of way  some    XmlSerializer  use a class with the target schema you want to read - use XmlSerializer to get the data in an Xml loaded into an instance of the class  Linq 2 xml XmlTextReader  XmlDocument XPathDocument  read-only access

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There are different ways  depending on where you want to get   XmlDocument is lighter than XDocument  but if you wish to verify minimalistically that a string contains XML  then regular expression is possibly the fastest and lightest choice you can make  For example  I have implemented Smoke Tests with SpecFlow for my API and I wish to test if one of the results in any valid XML - then I would use a regular expression  But if I need to extract values from this XML  then I would parse it with XDocument to do it faster and with less code  Or I would use XmlDocument if I have to work with a big XML  and sometimes I work with XML s that are around 1M lines  even more   then I could even read it line by line  Why  Try opening more than 800MB in private bytes in Visual Studio  even on production you should not have objects bigger than 2GB  You can with a twerk  but you should not  If you would have to parse a document  which contains A LOT of lines  then this documents would probably be CSV    I have written this comment  because I see a lof of examples with XDocument  XDocument is not good for big documents  or when you only want to verify if there the content is XML valid  If you wish to check if the XML itself makes sense  then you need Schema   I also downvoted the suggested answer  because I believe it needs the above information inside itself  Imagine I need to verify if 200M of XML  10 times an hour  is valid XML  XDocument will waste a lof of resources   prasanna venkatesh also states you could try filling the string to a dataset  it will indicate valid XML as well

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If you want to retrive a particular value from an XML file  XmlDocument  LocalInfo Xml   new XmlDocument                 LocalInfo Xml Load fileName               XmlElement  XmlElement               XmlElement    LocalInfo Xml GetElementsByTagName  quot UserId quot   0  as XmlElement              string Value    XmlElement InnerText

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XmlDocument to read an XML from string or from file   XmlDocument doc   new XmlDocument    doc Load  c   temp xml      or  doc LoadXml   lt xml gt something lt  xml gt       then find a node below it ie like this  XmlNode node   doc DocumentElement SelectSingleNode   book title      or  foreach XmlNode node in doc DocumentElement ChildNodes      string text   node InnerText    or loop through its children as well     then read the text inside that node like this  string text   node InnerText    or read an attribute  string attr   node Attributes  theattributename    InnerText   Always check for null on Attributes  something   since it will be null if the attribute does not exist

[c#] How do I read and parse an XML file in C#?

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