Parsing XML file C#

Question

I can't parse the attribute value from this file, I used Linq and the standard library. Object reference error. Need attribut's value "RequeryNumber".

XML file

Excel Query:

exctract = XML.DocumentElement
    .SelectSingleNode("//KPOKS/ReestrExtract/DeclarAttribute")
    .Attributes
    .getNamedItem("RequeryNumber").Text

Answer 1

SelectSingleNode() uses XPath to find XML nodes that fulfill the filter. There are several ways to get what you want. If RequeryNumber only exists on one node, you could do like this:

var attribute = xDoc.DocumentElement
    .SelectSingleNode("//*[@RequeryNumber]/@RequeryNumber");

MessageBox.Show("text" + attribute.InnerText);

[@RequeryNumber] finds the node which has an attribute named "RequeryNumber".

/@RequeryNumber extracts that specific attribute, on which you can get the value using the InnerText property.

I would suggest you take a look at: XPath cheatsheet

Answer 2

I had one error on following line in the xml that I fixed

I parsed below your xml and needed to add the namespace to get the XElement using Xml Linq.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.Xml.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        const string FILENAME = @"c:\temp\test.xml";
        static void Main(string[] args)
        {
            XDocument doc = XDocument.Load(FILENAME);
            XNamespace ns = doc.Root.GetDefaultNamespace();

            XElement declarAttribute = doc.Descendants(ns + "DeclarAttribute").FirstOrDefault();
        }
    }
}