using System.Text;
using System.Text.RegularExpressions;
public static class StringExtensions
{
public static string ToShortDescription(this string ls, int length)
    {
        if (!string.IsNullOrEmpty(ls.Trim()))
        {
            ls = ls.Trim().StripSpecialCharacters();

            if (ls.Length > length)
            {
                ls = ls.Substring(0, length - 3); //-3 for dots
                ls = ls.Remove(ls.LastIndexOf(" "), (ls.Length - ls.LastIndexOf(" ")));
                ls += "...";
            }

            return ls;
        }
        return string.Empty;
    }


public static string StripSpecialCharacters(this string s)
    {
        if (string.IsNullOrEmpty(s))
            return string.Empty;

        Regex r = new Regex(@"\s+");//remove all whitespace
        s = r.Replace(s, " ");	// to a single space

        MatchCollection mc = Regex.Matches(s, @"[A-Za-z0-9]|\s+", RegexOptions.IgnoreCase);
        s = string.Empty;
        foreach (Match m in mc)
        {
            s += m.ToString();
        }

        return s;
    }
  
}