using System;
using System.Text.RegularExpressions;
public class Example
{
public static void Main()
{
string pattern = @"<if>(.*?)<\/if>";
string input = @"Lorem ipsum dolor sit amet, consectetuer adipiscing elit, sed diam nonummy nibh euismod tincidunt ut<if>abc</if> laoreet dolore magna aliquam erat volutpat. Ut wisi enim ad minim veniam, quis nostrud exerci tation ullamcorper suscipit lobortis nisl ut aliquip ex {{test}}ea commodo consequat. Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse<if>123</if> molestie consequat, vel {{test}} illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio dignissim qui blandit praesent luptatum zzril delenit augue duis dolore te feugait nulla facilisi.
";
foreach (Match m in Regex.Matches(input, pattern))
{
Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index);
}
}
}
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