using System;

using System.Text.RegularExpressions;

​

namespace RegularExpressionPlayground

{

    class Program

    {

        const string text = "Professional C# 6 and .NET Core 1.0 provides complete coverage " + "of the latest updates, features, and capabilities, giving you " + "everything you need for C#. Get expert instruction on the latest " + "changes to Visual Studio 2015, Windows Runtime, ADO.NET, ASP.NET, " + "Windows Store Apps, Windows Workflow Foundation, and more, with " + "clear explanations, no-nonsense pacing, and valuable expert insight. " + "This incredibly useful guide serves as both tutorial and desk " + "reference, providing a professional-level review of C# architecture " + "and its application in a number of areas. You'll gain a solid " + "background in managed code and .NET constructs within the context of " + "the 2015 release, so you can get acclimated quickly and get back to work.";

        static void Main()

        {

            Find1(text);

        }

​

        public static void Find1(string text)

        {

            Console.WriteLine(nameof(Find1) + "\n");

            //const string pattern = "ion";           // Contenga la secuencia de caracteres "ion"

            //const string pattern = @"\ba";          //Inicia con "a" 

            const string pattern = @"\ba\S{8}ure\b"; //Inicia con "a" y termina con "ure"  S* indica cualquier cantidad de caracteres entre la a y ure, eso si omite los espacios en blanco.

            //const string pattern = @"\.";

            MatchCollection matches = Regex.Matches(text, pattern, RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture);

            WriteMatches(text, matches);

            Console.WriteLine();

        }

​

        public static void WriteMatches(string text, MatchCollection matches)

        {

            Console.WriteLine($"Original text was: \n\n{text}\n");

            Console.WriteLine($"No. of matches: {matches.Count}");

            foreach (Match nextMatch in matches)

            {

                int index = nextMatch.Index;

                string result = nextMatch.ToString();

                int charsBefore = (index < 5) ? index : 5;

                int fromEnd = text.Length - index - result.Length;

                int charsAfter = (fromEnd < 5) ? fromEnd : 5;

                int charsToDisplay = charsBefore + charsAfter + result.Length;

                Console.WriteLine($"Index: {index}, \tString: {result}, \t" + $"{text.Substring(index - charsBefore, charsToDisplay)}");

            }

        }

    }

}