How to validate XML dataset when hexadecimal invalid character arrives

Question

I am processing some xml document. while reading xml value through dataset, I am getting below error.

System.Xml.XmlException: ''', hexadecimal value 0x02, is an invalid character. Line 1, position 989.'

How to avoid this...? How to validate and handle this error. I am stuck in the project and not able to proceed due to this error...it is very urgent

Answer 1

Hi @BeUnique , Welcome to Microsoft Q&A,

The xml must not contain any errors when read. The correct way is to read it as a string and process anything unrecognizable first. One method is to use regular expressions to blank out all illegal characters.

As follows:

using System;
using System.Data;
using System.IO;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using System.Xml;

namespace _9_22_x
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string xmlData = @"<?xml version='1.0'?>
<!-- This file represents a fragment of a book store inventory database -->
<bookstore>
  <book genre=""autobiography"" publicationdate=""1981"" ISBN=""1-861003-11-0"">
    <title>The Autobiography of Benjamin Franklin</title>
    <author>
      <first-name>Benjamin</first-name>
      <last-name>Franklin</last-name>
    </author>
    <price>8.99</price>
  </book>
  <book genre=""novel"" publicationdate=""1967"" ISBN=""0-201-63361-2"">
    <title>The Confidence Man</title>
    <author>
      <first-name>Herman</first-name>
      <last-name>Melville</last-name>
    </author>
    <price>11.99</price>
  </book>
  <book genre=""philosophy"" publicationdate=""1991"" ISBN=""1-861001-57-6"">
    <title>The Gorgias</title>
    <author>
      <name>Plato</name>
    </author>
    <price>9.99</price>
  </book>
</bookstore>";
            //xmlData = xmlData.Replace(@"", "");
            string cleanedXml = RemoveUnrecognizedCharacters(xmlData);
            DataSet dataSet = new DataSet();
            try
            {
                dataSet.ReadXml(new StringReader(cleanedXml));
                dataGridView1.DataSource = dataSet.Tables[0];
                listBox1.DataSource = dataSet.Tables[0];
            }
            catch (XmlException ex)
            {
                Console.WriteLine("XML parsing error: " + ex.Message);
            }
        }
        static string RemoveUnrecognizedCharacters(string input)
        {
            return Regex.Replace(input, @"[^\x09\x0A\x0D\x20-\xD7FF\xE000-\xFFFD\x10000-x10FFFF]", string.Empty);
        }
    }
}

Best Regards,

Jiale

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