RandomString - A class containing methods to produce some handy random string combinations.

RandomString.cs

using System;
using System.Text;

namespace RandomString
{
    public class RandomString : IDisposable
    {
		// Can use the BetterRandom class here or just use the built-in System.Random class.
        private BetterRandom random = new BetterRandom();
        private const string alpha_selection = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
        private const string numeric_selection = "1234567890";
        private const string symbol_selection = "!£$%^&*()-+=";

        public string GenerateRandomString()
        {
            var length = random.Next(5, 15);
            return GenerateRandomString(length);
        }

        public string GenerateRandomString(int length, bool onlyUseAlphaNumerics = false)
        {
            var alphanumeric_selection = alpha_selection + numeric_selection;
            var characterSelection = onlyUseAlphaNumerics ? alphanumeric_selection : alphanumeric_selection + symbol_selection;
            return GenerateRandomString(length, characterSelection);
        }

        public string GenerateRandomString(int length, string characterSelection)
        {
            var result = new StringBuilder();
            for (var i = 0; i < length; i++)
            {
                var chr = characterSelection.Substring(random.Next(0, characterSelection.Length), 1);
                result.Append(chr);
            }
            return result.ToString();
        }

        public string GenerateHashString(string stringToHash)
        {
            using (var crypto = new System.Security.Cryptography.SHA1CryptoServiceProvider())
            {
                return BitConverter.ToString(crypto.ComputeHash(Encoding.Unicode.GetBytes(stringToHash))).Replace("-", string.Empty);
            }
        }

        public string GenerateRandomHashString()
        {
            return GenerateHashString(GenerateRandomString(1024));
        }


        public void Dispose()
        {
            Dispose(true);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (random != null)
                {
                    random.Dispose();
                    random = null;
                }
            }
            GC.SuppressFinalize(this);
        }
    }
}