Parse xml string and replace a particular character in C#

Prasant Jinaga

Hi,

I have a xml value in string which is having almost 500 characters.In that string if there is a character '<' I need to replace it with '>' in C#.Thanks in advance

Thanks,
Prasant

2 Replies

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Jignesh Trivedi14y ago
hi,

If you develped web application then you can also use "HttpUtility.HtmlEncode" which is from "System.Web" name space.

example:

string xml = @"

Tove
Jani
Reminder
1 < 2

Don't forget
";
;
string encodedXml = System.Web.HttpUtility.HtmlEncode(xml);
Output :
<?xml version='1.0' encoding='ISO-8859-1'?>
<note>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<heading>1 < 2</heading>

<body>Don't forget <me this weekend!<br /></body>
</note>
please refer
http://weblogs.sqlteam.com/mladenp/archive/2008/10/21/Different-ways-how-to-escape-an-XML-string-in-C.aspx
hope this will help you.
Vulpes14y ago
I can't promise that this will deal with everything but it should be able to deal with simple cases.

The idea is to first isolate all the tags and replace the '<' with some special character that won't otherwise appear in the XML string. I've used '~' for now but you can use a different character if you wish.

After doing this you can then find the remaining '<' which appear in the text and replace them with the corresponding entity <

Finally, you can replace the '~' with '<' to restore the tags.

using System;
using System.Text.RegularExpressions;

class Test
{
static void Main()
{
string xml = @"
Tove
Jani
Reminder
1 < 2

Don't forget
";

string regExp = @"";
MatchCollection mc = Regex.Matches(xml, regExp);
foreach(Match m in mc)
{
string val = m.Groups[1].Value;
string regExp2 = "<" + val + "( |>)";
Match m2 = Regex.Match(xml, regExp2);
if (m2.Success)
{
char[] chars = xml.ToCharArray();
chars[m2.Index] = '~';
xml = new string(chars);
xml = Regex.Replace(xml, @"", "~/" + val + ">");
}

xml = Regex.Replace(xml, @"<\?", @"~?"); // declarations
xml = Regex.Replace(xml, @"
}

string regExp3 = @"<\w+\s?/>";
Match m3 = Regex.Match(xml, regExp3);
if (m3.Success)
{
char[] chars = xml.ToCharArray();
chars[m3.Index] = '~';
xml = new string(chars);
}
xml = Regex.Replace(xml, "<", "<");
xml = Regex.Replace(xml, "~", "<");
Console.WriteLine(xml);
Console.ReadKey();
}
}

The output should be:

Tove
Jani
Reminder
1 < 2

Don't forget <me this weekend!