using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"(\[a\])([^\[]+)(\[\/a\])";
string substitution = @"<a href='$2'>$2</a>";
string input = @"[a]http://first.com/hi_underscoredot.htm[/a] [a]http://secondinoneline.com/hi_.htm[/a]";
Regex regex = new Regex(pattern);
string result = regex.Replace(input, substitution);
}
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx