Development Class C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Security.Cryptography;
using System.Text;
namespace Dropboxifier
{
    static public class FileUtils
    {
        /// 
        /// Given a directory select a random file from it.
        /// 

        static public string SelectRandomFileFromFolder(string folderName)
        {
            DirectoryInfo di = new DirectoryInfo(folderName);
            if (di.Exists)
            {
                FileInfo[] files = di.GetFiles();
                if (files.Length > 0)
                {
                    Random randGenerator = new Random();
                    int index = randGenerator.Next(0, files.Length - 1);
                    return files[index].FullName;
                }
            }
            return null;
        }
    }
}