转义xml中的特殊字符

Question

Using Regex, how can I escape special characters in xml attribute values?

Given the following xml as string:

"<node attr=\"<Sample>\"></node>"

I want to get:

"<node attr=\"&lt;Sample&gt;\"></node>"

System.Security.SecurityElement.Escape function won't work as it tries to escape every special characters (including tag opening/closing angle brackets).

Answer 1

string text = "<node attr=\"<Sample>\"></node>";

string pattern = @"(?<=\b\w+\s*=\s*"")<\w+>(?="")";

string result = Regex.Replace(text, pattern, m => SecurityElement.Escape(m.Value));

Console.WriteLine(text);
Console.WriteLine(result);

Where:
?<= - positive lookbehind
\\b - start the match at a word boundary
\\w+ - match one or more word characters
\\s* - match zero or more white-space characters
?= - positive lookahead