Need help in parsing a huge XML file in windows application

Aisha Iyer

Hi,
I have a huge XML file which is a collection of nodes. I want to extract each node and then extract the required field information from it. I am currently reading this file in a string which is so large that I can have only 1 copy of the string in memory. Even a Split operation on the string throws "Out of memory" exception. So I am using Substring() method to read each of the fileDocument node in loop. Is there a better data structure (than string) to read the XML file. Using XMLDocument() , throws an error that "0x1C Hexadecimal character found". So I am not able to use any XML functions on this XML file. Please help.
P.S. The reason for looking for an alternate data structure is to get an improvement in performance. Is there a way I can get that improvement using string itself?

5 Replies

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15y ago
Accepted answer
Good.. :)
If my post helped you please Mark As Answer !
Sam Hobbs15y ago
Are you familiar with try/catch blocks? You perhaps could have solved the problem of thrown exceptions that way. I don't know the details of how you were using XMLDocument but the "0x1C Hexadecimal character found" exception can perhaps be ignored using try/catch blocks.
Aisha Iyer15y ago
Thanks Murali, I just tried the suggestions given in
http://seattlesoftware.wordpress.com/2008/09/11/hexadecimal-value-0-is-an-invalid-character/
and it worked for me. Thanks a lot :)
15y ago
Please see the below links....
http://seattlesoftware.wordpress.com/2008/09/11/hexadecimal-value-0-is-an-invalid-character/
http://old.nabble.com/An-invalid-XML-character-(Unicode%3A-0x1c)-td14105005.html
Please try use to Linq to XML.
Shankey15y ago
hi aisha,

u can try something as shown below.

XmlReader _sReader = openXmlFile(filepath);

             #region try

            try

            { // loop continue till reaches end of file

                while (!_sReader.EOF)

                { // check Node type,node name

                    if ((_xReader.MoveToContent() == XmlNodeType.Element) && _sReader.Name == "Filedocument")

                    {

                        XmlDocument doc = new XmlDocument();

                        // get node

                        XmlNode snode = doc.ReadNode(_sReader);

                        // play attribute

                        InitialiseSubNodes (snode);

                    }

                    else

                    {

                        _sReader.Read();

                    }

                }

            }

            catch (Exception ex)

            {

                Console.Write(ex.Message);

            }

            finally

            {

                _sReader.Close();

            }

            #endregion

        public void InitialiseSubNodes(XmlNode node)
        {

            XmlNode snode;

            XmlNodeList list = node.ChildNodes;

            if (xnode.HasChildNodes)

            {

                for (int c = 0; c < list.Count; c++)

                {

                    snode = node.ChildNodes[c];

                    string property = snode.LocalName;

                    switch (property)

                    {

                        case "sub nodes1":

                            break;

                        case "sub node2":

                            break;

                        default:

                            break;

                    }

                }

            }

        }