SHA1

using System;
using System.Security.Cryptography;
using System.Text;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            string source = "Hello World!";
            using (SHA1 sha1Hash = SHA1.Create())
            {
                //From String to byte array
                byte[] sourceBytes = Encoding.UTF8.GetBytes(source);
                byte[] hashBytes = sha1Hash.ComputeHash(sourceBytes);
                string hash = BitConverter.ToString(hashBytes).Replace("-",String.Empty);

                Console.WriteLine("The SHA1 hash of " + source + " is: " + hash);     
            }
        } 
    }
 }

输出：

Hello Word 的 SHA1 哈希值！ 是：2EF7BDE608CE5404E97D5F042F95F89F1C232871