Sha1 Hash generation Tool using C#.NET

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Security.Cryptography;

namespace sha1_csharp
{
    class Program
    {
        static void Main(string[] args)
        {

            string tmpHash;

            tmpHash = SHA1HashEncode("aa", EncodeStyle.Hex);
            Console.WriteLine(tmpHash);
            Console.ReadLine();

        }// main




public enum EncodeStyle
{
  Dig,Hex,Base64
};

static string ByteArrayToString(byte[] arrInput, EncodeStyle encode)
{
  int i;
  StringBuilder sOutput = new StringBuilder(arrInput.Length);
  if(EncodeStyle.Base64 == encode)
  {
     return Convert.ToBase64String(arrInput);
  }
  for (i = 0; i < arrInput.Length; i++)
  {
    switch(encode)
    {
       case EncodeStyle.Dig:
       //encode to decimal with 3 digits so 7 will be 007 (as range of 8 bit is 127 to -128)
       sOutput.Append(arrInput[i].ToString("D3"));
       break;
       case EncodeStyle.Hex:
       sOutput.Append(arrInput[i].ToString("X2"));
       break;
    }
  }
  return sOutput.ToString();
}

static string SHA1HashEncode(string filePath, EncodeStyle encode)
{
  SHA1 a = new SHA1CryptoServiceProvider();
  byte[] arr = new byte[60];
 //  string hash = "aa";
  string hash = "";
  arr = a.ComputeHash(ASCIIEncoding.ASCII.GetBytes(filePath)); // burası benden :D !!!!!!!!!!!!!!!!!!!!


    /*
  filePath = "aa";
  filePath = System.Text.Encoding.UTF8.GetString(arr);      * /
    /*
  using (StreamReader sr = new StreamReader(filePath))
  {
     arr = a.ComputeHash(sr.BaseStream);
     hash = ByteArrayToString(arr, encode);
  }
     */

  hash = ByteArrayToString(arr, encode);

  return hash;
}





    }// class **

}// namespace