Benchmark for reversing strings

/*
 * Created by SharpDevelop.
 * User: Hanpari
 * Date: 15. 3. 2015
 * Time: 18:10
 *
 * To change this template use Tools | Options | Coding | Edit Standard Headers.
 */
using System;
using System.Collections.Generic;
using System.Linq;

namespace csharp
{
    /// <summary>
    /// Description of Benchmark.
    /// </summary>
    public class Benchmark
    {

        private int Repeat;
        private int LengthOfString;
        private string SentenceForReverse;
        private Dictionary<string, TimeSpan> Results;
        private delegate string ReverseStringDelegate(string Sentence);

        public Benchmark(int LengthOfString, int Repeat)
        {
            this.Repeat = Repeat;
            this.LengthOfString = LengthOfString;
            this.SentenceForReverse = CreateString();
            this.Results = new Dictionary<string, TimeSpan>();

        }

        private TimeSpan Timeit(ReverseStringDelegate ReverseString)
        {
            var start = DateTime.Now;
            for (int i = 0; i < this.Repeat; i++)
            {
                ReverseString(this.SentenceForReverse);
            }
            return DateTime.Now - start;

        }

        private string CreateString()
        {
            var r = new Random();
            string newstr = "";
            for (int i = 0; i < this.LengthOfString; i++)
            {
                newstr += Char.ConvertFromUtf32(r.Next(65, 122));
            }
            return newstr;
        }


        private string ReverseByIteration(string ToBeReversed)
        {
            char[] pole = ToBeReversed.ToCharArray();
            int i = 0, j = pole.Length - 1;
            while (i < j)
                {
                 char tmp = pole[i];
                 pole[i] = pole[j];
                 pole[j] = tmp;
                 i++;
                 j--;
                }
            return new string(pole);
        }

        private string ReverseByCharArray(string ToBeReversed)
        {
            var arr = ToBeReversed.ToCharArray();
            Array.Reverse(arr);
            return new string(arr);
        }

        private string ReverseByList(string ToBeReversed)
        {

             var tmp = ToBeReversed.ToCharArray().ToList();
             tmp.Reverse();
             return new string(tmp.ToArray());

        }

        private string ReverseByEnumeration(string ToBeReversed)
        {
            return new string(ToBeReversed.Reverse().ToArray());
        }

        public void PrintResults()
        {
            Console.WriteLine("Length of tested sentence is: {0} chars.", this.LengthOfString);
            Console.WriteLine("Number of repetion is: {0}", this.Repeat);
            Console.WriteLine("Starting to evaluate...");
            this.Evaluate();
            var results = from entry in this.Results
                            orderby entry.Value descending
                            select entry;

            foreach (var entry in results)
            {
                Console.WriteLine(entry);
            }
            Console.ReadKey();

        }

        private void Evaluate()
        {
            this.Results.Add("Iterace",
                             Timeit(new ReverseStringDelegate(ReverseByIteration)));
            this.Results.Add("CharArray",
                             Timeit(new ReverseStringDelegate(ReverseByCharArray)));
            this.Results.Add("ListMethod",
                             Timeit(new ReverseStringDelegate(ReverseByList)));
            this.Results.Add("Enumerace",
                             Timeit(new ReverseStringDelegate(ReverseByEnumeration)));

        }

    }

}