Cannot insert the node in the specified location in xml

Question

I am creating xml from c# code.I am gettign the following error: Cannot insert the node in the specified location.

My code to do so is:

  try {           
        XmlDocument doc = new XmlDocument();
        XmlNode docNode = doc.CreateXmlDeclaration("1.0", "utf-8", null);
        doc.AppendChild(docNode);

        // XmlNode openerpNode = doc.CreateElement("open");
        doc.AppendChild(openerpNode);

        XmlElement dataNode = doc.CreateElement("dataex");
        openerpNode.AppendChild(dataNode);
        doc.PrependChild(colName.GenerateColumnsForTable("code", doc, dataNode));  //THIS LINE CAUSES ERROR AND THIS FUNCTON RETURNS A XmlNode TYPE OBJECT "dataNode"
//I use PrependChild here because i will call this function again passing another string in first parameter and it should attach the same xml
        Console.WriteLine("string is : " + doc);
        Console.ReadKey();
        doc.Save("C:/cod.xml");
        return true;
    } catch (Exception ex) {
        Console.WriteLine("The error is :" + ex);
        Console.ReadKey();
        return false;
    }



public class ReturnColumnName
    {
        public XmlNode GenerateColumnsForTable(string tableName, XmlDocument doc, XmlNode dataNode)
        {

          //Here i am using the same doc and dataNode to create xml
          return dataNode;
        }
    }

EDIT: I changed the code from this

 doc.PrependChild(colName.GenerateColumnsForTable("code_pays_iso", doc, dataNode));

to

 XmlNode nod = colName.GenerateColumnsForTable("code_colisage", doc,dataNode);
 doc.AppendChild(doc.OwnerDocument.ImportNode(nod, true));

Now it gives this error :

The error is :System.NullReferenceException: Object reference not set to an instance of an object.

Could some one please help me in finding the cause of error

Does it help if instead of passing doc and dataNode by value you pass them by reference and don't return: public void GenerateColumnsForTable(string tableName, ref XmlDocument doc, ref XmlNode dataNode) — Neal, Sep 01 '15 at 12:05

score 0 · Answer 1 · answered Sep 01 '15 at 14:52

You can't add a node to itself

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {

            try
            {
                ReturnColumnName colName = new ReturnColumnName();
                string input = "<?xml version=\"1.0\"?><open></open>";
                XmlDocument doc = new XmlDocument();
                doc.LoadXml(input);
                XmlElement opener = (XmlElement)doc.GetElementsByTagName("open")[0];

                XmlElement dataNode = doc.CreateElement("dataex");

                XmlElement child = (XmlElement)colName.GenerateColumnsForTable("code", doc, dataNode);
                if (opener.ChildNodes.Count == 0)
                {
                    opener.AppendChild(child);
                }
                else
                {
                    opener.PrependChild(child);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("The error is :" + ex);
                Console.ReadKey();
            }

        }
        public class ReturnColumnName
        {
            public XmlNode GenerateColumnsForTable(string tableName, XmlDocument doc, XmlNode dataNode)
            {

                //Here i am using the same doc and dataNode to create xml
                return dataNode;
            }
        }
    }
}

Cannot insert the node in the specified location in xml

1 Answers1