解析 EntityName 时出错。 第 1 行，位置 844

Question

I have got the following exception from the below code block.

An error occurred while parsing EntityName. Line1, position 844.

I was trying to parse s set of data retrieved from table to a data set.

public DataSet BindMasterData(string xml)
        {
            DataSet ds = null;
            try
            {
                ds = new DataSet();
                TextReader txtReader = new StringReader(xml);
                XmlReader reader = new XmlTextReader(txtReader);
                ds.ReadXml(reader);
            }
            catch (Exception ex)
            {
                return new DataSet();
            }
            return ds;
        }

I have figured out the reason for the exception, but I couldn't solve it. In this particular situation, the string(which is retrieved from DB) contains a special character (&). That causes exception. How I can solve it. Any help on this would be great.

Answer 1

Just replace them:

Not valid in XML elements:

"   "
'   '
<   &lt;
>   &gt;
&   &amp;

---

  public static string UnescapeXMLValue(string xmlString)
  {
    if (xmlString == null)
        throw new ArgumentNullException("xmlString")

    return xmlString.Replace("&apos;", "'").Replace("&quot;", "\"").Replace("&gt;", ">").Replace("&lt;", "<").Replace("&amp;", "&");
  }

 public static string EscapeXMLValue(string xmlString)
  {

    if (xmlString == null)
        throw new ArgumentNullException("xmlString")

    return xmlString.Replace("'","&apos;").Replace( "\"", "&quot;").Replace(">","&gt;").Replace( "<","&lt;").Replace( "&","&amp;");
  }

Answer 2

This has already been answered, but found a nicer way of achieving the same outcome by doing this in .NET 4.5 by using the Escape method as below:

var xmlWithEscapedCharacters = SecurityElement.Escape(xmlWithoutEscapedCharacters);

and then just plug that string into the XML that is being generated.

Link: MSDN - SecurityElement.Escape Method

Answer 3

If your XML is being constructed with string concatenation then you'll be wanting to escape it. & should become & while < and > should become < and > respectively.

There may be others too. Of course you should really use a proper XML encoder rather than trying to do it yourself for many reasons.

Answer 4

As the data comes from some data base, the problem can be hot-fixed in the context you described, but I would strongly recommend a different approach. The ampersand symbol should not have occured in the xml in the first place, as discussed here . Please clarify how the xml is generated and address the problem there.

Answer 5

You can use: SecurityElement.Escape(XML string)

Reference link: https://msdn.microsoft.com/en-us/library/system.security.securityelement.escape(v=vs.110).aspx