using System;

using System.Text;

using System.Security.Cryptography;

​

public class Program

{

    public static void Main()

    {

        var s = "123456789";

        var hash = ComputeSHA256(s);

        Console.WriteLine($"Sha256 of {s} computes to {hash}");

    }

​

    static string ComputeSHA256(string s)

    {

        using (SHA256 sha256 = SHA256.Create())

        {

            byte[] hashValue = sha256.ComputeHash(Encoding.UTF8.GetBytes(s));

            return Convert.ToHexString(hashValue);

        }

    }

}