using System;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        // Create a pattern to get text between <pre> tags  

        string pattern = @"(?<=<pre>)(.*?)(?=<\/pre>)";

        // Create a Regex  

        Regex rg = new Regex(pattern);

        // Long string  

        string html = "<h1>test</h1> some example text and stuff <pre>This is some text</pre>";

        // Get all matches  

        MatchCollection matchedHTML = rg.Matches(html);

        // Get the first value of the matched array. There could be multiple matches but we will print the first (index 0)

        Console.WriteLine(matchedHTML[0].Value);

    }

}